File: memline.c

package info (click to toggle)
vim 1:7.1.314-3+lenny2
  • links: PTS, VCS
  • area: main
  • in suites: lenny
  • size: 39,856 kB
  • ctags: 25,430
  • sloc: ansic: 279,681; cpp: 3,229; makefile: 2,958; perl: 1,232; sh: 857; awk: 715; xml: 507; cs: 458; asm: 114; python: 28; csh: 6
file content (4861 lines) | stat: -rw-r--r-- 131,262 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
/* vi:set ts=8 sts=4 sw=4:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/* for debugging */
/* #define CHECK(c, s)	if (c) EMSG(s) */
#define CHECK(c, s)

/*
 * memline.c: Contains the functions for appending, deleting and changing the
 * text lines. The memfile functions are used to store the information in
 * blocks of memory, backed up by a file. The structure of the information is
 * a tree.  The root of the tree is a pointer block. The leaves of the tree
 * are data blocks. In between may be several layers of pointer blocks,
 * forming branches.
 *
 * Three types of blocks are used:
 * - Block nr 0 contains information for recovery
 * - Pointer blocks contain list of pointers to other blocks.
 * - Data blocks contain the actual text.
 *
 * Block nr 0 contains the block0 structure (see below).
 *
 * Block nr 1 is the first pointer block. It is the root of the tree.
 * Other pointer blocks are branches.
 *
 *  If a line is too big to fit in a single page, the block containing that
 *  line is made big enough to hold the line. It may span several pages.
 *  Otherwise all blocks are one page.
 *
 *  A data block that was filled when starting to edit a file and was not
 *  changed since then, can have a negative block number. This means that it
 *  has not yet been assigned a place in the file. When recovering, the lines
 *  in this data block can be read from the original file. When the block is
 *  changed (lines appended/deleted/changed) or when it is flushed it gets a
 *  positive number. Use mf_trans_del() to get the new number, before calling
 *  mf_get().
 */

#if defined(MSDOS) || defined(WIN32) || defined(_WIN64)
# include "vimio.h"
#endif

#include "vim.h"

#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif
#ifndef UNIX		/* it's in os_unix.h for Unix */
# include <time.h>
#endif

#if defined(SASC) || defined(__amigaos4__)
# include <proto/dos.h>	    /* for Open() and Close() */
#endif

#ifdef HAVE_ERRNO_H
# include <errno.h>
#endif

typedef struct block0		ZERO_BL;    /* contents of the first block */
typedef struct pointer_block	PTR_BL;	    /* contents of a pointer block */
typedef struct data_block	DATA_BL;    /* contents of a data block */
typedef struct pointer_entry	PTR_EN;	    /* block/line-count pair */

#define DATA_ID	    (('d' << 8) + 'a')	    /* data block id */
#define PTR_ID	    (('p' << 8) + 't')	    /* pointer block id */
#define BLOCK0_ID0  'b'			    /* block 0 id 0 */
#define BLOCK0_ID1  '0'			    /* block 0 id 1 */

/*
 * pointer to a block, used in a pointer block
 */
struct pointer_entry
{
    blocknr_T	pe_bnum;	/* block number */
    linenr_T	pe_line_count;	/* number of lines in this branch */
    linenr_T	pe_old_lnum;	/* lnum for this block (for recovery) */
    int		pe_page_count;	/* number of pages in block pe_bnum */
};

/*
 * A pointer block contains a list of branches in the tree.
 */
struct pointer_block
{
    short_u	pb_id;		/* ID for pointer block: PTR_ID */
    short_u	pb_count;	/* number of pointer in this block */
    short_u	pb_count_max;	/* maximum value for pb_count */
    PTR_EN	pb_pointer[1];	/* list of pointers to blocks (actually longer)
				 * followed by empty space until end of page */
};

/*
 * A data block is a leaf in the tree.
 *
 * The text of the lines is at the end of the block. The text of the first line
 * in the block is put at the end, the text of the second line in front of it,
 * etc. Thus the order of the lines is the opposite of the line number.
 */
struct data_block
{
    short_u	db_id;		/* ID for data block: DATA_ID */
    unsigned	db_free;	/* free space available */
    unsigned	db_txt_start;	/* byte where text starts */
    unsigned	db_txt_end;	/* byte just after data block */
    linenr_T	db_line_count;	/* number of lines in this block */
    unsigned	db_index[1];	/* index for start of line (actually bigger)
				 * followed by empty space upto db_txt_start
				 * followed by the text in the lines until
				 * end of page */
};

/*
 * The low bits of db_index hold the actual index. The topmost bit is
 * used for the global command to be able to mark a line.
 * This method is not clean, but otherwise there would be at least one extra
 * byte used for each line.
 * The mark has to be in this place to keep it with the correct line when other
 * lines are inserted or deleted.
 */
#define DB_MARKED	((unsigned)1 << ((sizeof(unsigned) * 8) - 1))
#define DB_INDEX_MASK	(~DB_MARKED)

#define INDEX_SIZE  (sizeof(unsigned))	    /* size of one db_index entry */
#define HEADER_SIZE (sizeof(DATA_BL) - INDEX_SIZE)  /* size of data block header */

#define B0_FNAME_SIZE_ORG	900	/* what it was in older versions */
#define B0_FNAME_SIZE		898
#define B0_UNAME_SIZE		40
#define B0_HNAME_SIZE		40
/*
 * Restrict the numbers to 32 bits, otherwise most compilers will complain.
 * This won't detect a 64 bit machine that only swaps a byte in the top 32
 * bits, but that is crazy anyway.
 */
#define B0_MAGIC_LONG	0x30313233L
#define B0_MAGIC_INT	0x20212223L
#define B0_MAGIC_SHORT	0x10111213L
#define B0_MAGIC_CHAR	0x55

/*
 * Block zero holds all info about the swap file.
 *
 * NOTE: DEFINITION OF BLOCK 0 SHOULD NOT CHANGE! It would make all existing
 * swap files unusable!
 *
 * If size of block0 changes anyway, adjust MIN_SWAP_PAGE_SIZE in vim.h!!
 *
 * This block is built up of single bytes, to make it portable across
 * different machines. b0_magic_* is used to check the byte order and size of
 * variables, because the rest of the swap file is not portable.
 */
struct block0
{
    char_u	b0_id[2];	/* id for block 0: BLOCK0_ID0 and BLOCK0_ID1 */
    char_u	b0_version[10];	/* Vim version string */
    char_u	b0_page_size[4];/* number of bytes per page */
    char_u	b0_mtime[4];	/* last modification time of file */
    char_u	b0_ino[4];	/* inode of b0_fname */
    char_u	b0_pid[4];	/* process id of creator (or 0) */
    char_u	b0_uname[B0_UNAME_SIZE]; /* name of user (uid if no name) */
    char_u	b0_hname[B0_HNAME_SIZE]; /* host name (if it has a name) */
    char_u	b0_fname[B0_FNAME_SIZE_ORG]; /* name of file being edited */
    long	b0_magic_long;	/* check for byte order of long */
    int		b0_magic_int;	/* check for byte order of int */
    short	b0_magic_short;	/* check for byte order of short */
    char_u	b0_magic_char;	/* check for last char */
};

/*
 * Note: b0_dirty and b0_flags are put at the end of the file name.  For very
 * long file names in older versions of Vim they are invalid.
 * The 'fileencoding' comes before b0_flags, with a NUL in front.  But only
 * when there is room, for very long file names it's omitted.
 */
#define B0_DIRTY	0x55
#define b0_dirty	b0_fname[B0_FNAME_SIZE_ORG-1]

/*
 * The b0_flags field is new in Vim 7.0.
 */
#define b0_flags	b0_fname[B0_FNAME_SIZE_ORG-2]

/* The lowest two bits contain the fileformat.  Zero means it's not set
 * (compatible with Vim 6.x), otherwise it's EOL_UNIX + 1, EOL_DOS + 1 or
 * EOL_MAC + 1. */
#define B0_FF_MASK	3

/* Swap file is in directory of edited file.  Used to find the file from
 * different mount points. */
#define B0_SAME_DIR	4

/* The 'fileencoding' is at the end of b0_fname[], with a NUL in front of it.
 * When empty there is only the NUL. */
#define B0_HAS_FENC	8

#define STACK_INCR	5	/* nr of entries added to ml_stack at a time */

/*
 * The line number where the first mark may be is remembered.
 * If it is 0 there are no marks at all.
 * (always used for the current buffer only, no buffer change possible while
 * executing a global command).
 */
static linenr_T	lowest_marked = 0;

/*
 * arguments for ml_find_line()
 */
#define ML_DELETE	0x11	    /* delete line */
#define ML_INSERT	0x12	    /* insert line */
#define ML_FIND		0x13	    /* just find the line */
#define ML_FLUSH	0x02	    /* flush locked block */
#define ML_SIMPLE(x)	(x & 0x10)  /* DEL, INS or FIND */

static void ml_upd_block0 __ARGS((buf_T *buf, int set_fname));
static void set_b0_fname __ARGS((ZERO_BL *, buf_T *buf));
static void set_b0_dir_flag __ARGS((ZERO_BL *b0p, buf_T *buf));
#ifdef FEAT_MBYTE
static void add_b0_fenc __ARGS((ZERO_BL *b0p, buf_T *buf));
#endif
static time_t swapfile_info __ARGS((char_u *));
static int recov_file_names __ARGS((char_u **, char_u *, int prepend_dot));
static int ml_append_int __ARGS((buf_T *, linenr_T, char_u *, colnr_T, int, int));
static int ml_delete_int __ARGS((buf_T *, linenr_T, int));
static char_u *findswapname __ARGS((buf_T *, char_u **, char_u *));
static void ml_flush_line __ARGS((buf_T *));
static bhdr_T *ml_new_data __ARGS((memfile_T *, int, int));
static bhdr_T *ml_new_ptr __ARGS((memfile_T *));
static bhdr_T *ml_find_line __ARGS((buf_T *, linenr_T, int));
static int ml_add_stack __ARGS((buf_T *));
static void ml_lineadd __ARGS((buf_T *, int));
static int b0_magic_wrong __ARGS((ZERO_BL *));
#ifdef CHECK_INODE
static int fnamecmp_ino __ARGS((char_u *, char_u *, long));
#endif
static void long_to_char __ARGS((long, char_u *));
static long char_to_long __ARGS((char_u *));
#if defined(UNIX) || defined(WIN3264)
static char_u *make_percent_swname __ARGS((char_u *dir, char_u *name));
#endif
#ifdef FEAT_BYTEOFF
static void ml_updatechunk __ARGS((buf_T *buf, long line, long len, int updtype));
#endif

/*
 * Open a new memline for "buf".
 *
 * Return FAIL for failure, OK otherwise.
 */
    int
ml_open(buf)
    buf_T	*buf;
{
    memfile_T	*mfp;
    bhdr_T	*hp = NULL;
    ZERO_BL	*b0p;
    PTR_BL	*pp;
    DATA_BL	*dp;

    /*
     * init fields in memline struct
     */
    buf->b_ml.ml_stack_size = 0;	/* no stack yet */
    buf->b_ml.ml_stack = NULL;	/* no stack yet */
    buf->b_ml.ml_stack_top = 0;	/* nothing in the stack */
    buf->b_ml.ml_locked = NULL;	/* no cached block */
    buf->b_ml.ml_line_lnum = 0;	/* no cached line */
#ifdef FEAT_BYTEOFF
    buf->b_ml.ml_chunksize = NULL;
#endif

    /*
     * When 'updatecount' is non-zero swap file may be opened later.
     */
    if (p_uc && buf->b_p_swf)
	buf->b_may_swap = TRUE;
    else
	buf->b_may_swap = FALSE;

    /*
     * Open the memfile.  No swap file is created yet.
     */
    mfp = mf_open(NULL, 0);
    if (mfp == NULL)
	goto error;

    buf->b_ml.ml_mfp = mfp;
    buf->b_ml.ml_flags = ML_EMPTY;
    buf->b_ml.ml_line_count = 1;
#ifdef FEAT_LINEBREAK
    curwin->w_nrwidth_line_count = 0;
#endif

#if defined(MSDOS) && !defined(DJGPP)
    /* for 16 bit MS-DOS create a swapfile now, because we run out of
     * memory very quickly */
    if (p_uc != 0)
	ml_open_file(buf);
#endif

/*
 * fill block0 struct and write page 0
 */
    if ((hp = mf_new(mfp, FALSE, 1)) == NULL)
	goto error;
    if (hp->bh_bnum != 0)
    {
	EMSG(_("E298: Didn't get block nr 0?"));
	goto error;
    }
    b0p = (ZERO_BL *)(hp->bh_data);

    b0p->b0_id[0] = BLOCK0_ID0;
    b0p->b0_id[1] = BLOCK0_ID1;
    b0p->b0_magic_long = (long)B0_MAGIC_LONG;
    b0p->b0_magic_int = (int)B0_MAGIC_INT;
    b0p->b0_magic_short = (short)B0_MAGIC_SHORT;
    b0p->b0_magic_char = B0_MAGIC_CHAR;
    STRNCPY(b0p->b0_version, "VIM ", 4);
    STRNCPY(b0p->b0_version + 4, Version, 6);
    long_to_char((long)mfp->mf_page_size, b0p->b0_page_size);

#ifdef FEAT_SPELL
    if (!buf->b_spell)
#endif
    {
	b0p->b0_dirty = buf->b_changed ? B0_DIRTY : 0;
	b0p->b0_flags = get_fileformat(buf) + 1;
	set_b0_fname(b0p, buf);
	(void)get_user_name(b0p->b0_uname, B0_UNAME_SIZE);
	b0p->b0_uname[B0_UNAME_SIZE - 1] = NUL;
	mch_get_host_name(b0p->b0_hname, B0_HNAME_SIZE);
	b0p->b0_hname[B0_HNAME_SIZE - 1] = NUL;
	long_to_char(mch_get_pid(), b0p->b0_pid);
    }

    /*
     * Always sync block number 0 to disk, so we can check the file name in
     * the swap file in findswapname(). Don't do this for help files though
     * and spell buffer though.
     * Only works when there's a swapfile, otherwise it's done when the file
     * is created.
     */
    mf_put(mfp, hp, TRUE, FALSE);
    if (!buf->b_help && !B_SPELL(buf))
	(void)mf_sync(mfp, 0);

    /*
     * Fill in root pointer block and write page 1.
     */
    if ((hp = ml_new_ptr(mfp)) == NULL)
	goto error;
    if (hp->bh_bnum != 1)
    {
	EMSG(_("E298: Didn't get block nr 1?"));
	goto error;
    }
    pp = (PTR_BL *)(hp->bh_data);
    pp->pb_count = 1;
    pp->pb_pointer[0].pe_bnum = 2;
    pp->pb_pointer[0].pe_page_count = 1;
    pp->pb_pointer[0].pe_old_lnum = 1;
    pp->pb_pointer[0].pe_line_count = 1;    /* line count after insertion */
    mf_put(mfp, hp, TRUE, FALSE);

    /*
     * Allocate first data block and create an empty line 1.
     */
    if ((hp = ml_new_data(mfp, FALSE, 1)) == NULL)
	goto error;
    if (hp->bh_bnum != 2)
    {
	EMSG(_("E298: Didn't get block nr 2?"));
	goto error;
    }

    dp = (DATA_BL *)(hp->bh_data);
    dp->db_index[0] = --dp->db_txt_start;	/* at end of block */
    dp->db_free -= 1 + INDEX_SIZE;
    dp->db_line_count = 1;
    *((char_u *)dp + dp->db_txt_start) = NUL;	/* emtpy line */

    return OK;

error:
    if (mfp != NULL)
    {
	if (hp)
	    mf_put(mfp, hp, FALSE, FALSE);
	mf_close(mfp, TRUE);	    /* will also free(mfp->mf_fname) */
    }
    buf->b_ml.ml_mfp = NULL;
    return FAIL;
}

/*
 * ml_setname() is called when the file name of "buf" has been changed.
 * It may rename the swap file.
 */
    void
ml_setname(buf)
    buf_T	*buf;
{
    int		success = FALSE;
    memfile_T	*mfp;
    char_u	*fname;
    char_u	*dirp;
#if defined(MSDOS) || defined(MSWIN)
    char_u	*p;
#endif

    mfp = buf->b_ml.ml_mfp;
    if (mfp->mf_fd < 0)		    /* there is no swap file yet */
    {
	/*
	 * When 'updatecount' is 0 and 'noswapfile' there is no swap file.
	 * For help files we will make a swap file now.
	 */
	if (p_uc != 0)
	    ml_open_file(buf);	    /* create a swap file */
	return;
    }

    /*
     * Try all directories in the 'directory' option.
     */
    dirp = p_dir;
    for (;;)
    {
	if (*dirp == NUL)	    /* tried all directories, fail */
	    break;
	fname = findswapname(buf, &dirp, mfp->mf_fname);
						    /* alloc's fname */
	if (fname == NULL)	    /* no file name found for this dir */
	    continue;

#if defined(MSDOS) || defined(MSWIN)
	/*
	 * Set full pathname for swap file now, because a ":!cd dir" may
	 * change directory without us knowing it.
	 */
	p = FullName_save(fname, FALSE);
	vim_free(fname);
	fname = p;
	if (fname == NULL)
	    continue;
#endif
	/* if the file name is the same we don't have to do anything */
	if (fnamecmp(fname, mfp->mf_fname) == 0)
	{
	    vim_free(fname);
	    success = TRUE;
	    break;
	}
	/* need to close the swap file before renaming */
	if (mfp->mf_fd >= 0)
	{
	    close(mfp->mf_fd);
	    mfp->mf_fd = -1;
	}

	/* try to rename the swap file */
	if (vim_rename(mfp->mf_fname, fname) == 0)
	{
	    success = TRUE;
	    vim_free(mfp->mf_fname);
	    mfp->mf_fname = fname;
	    vim_free(mfp->mf_ffname);
#if defined(MSDOS) || defined(MSWIN)
	    mfp->mf_ffname = NULL;  /* mf_fname is full pathname already */
#else
	    mf_set_ffname(mfp);
#endif
	    ml_upd_block0(buf, FALSE);
	    break;
	}
	vim_free(fname);	    /* this fname didn't work, try another */
    }

    if (mfp->mf_fd == -1)	    /* need to (re)open the swap file */
    {
	mfp->mf_fd = mch_open((char *)mfp->mf_fname, O_RDWR | O_EXTRA, 0);
	if (mfp->mf_fd < 0)
	{
	    /* could not (re)open the swap file, what can we do???? */
	    EMSG(_("E301: Oops, lost the swap file!!!"));
	    return;
	}
    }
    if (!success)
	EMSG(_("E302: Could not rename swap file"));
}

/*
 * Open a file for the memfile for all buffers that are not readonly or have
 * been modified.
 * Used when 'updatecount' changes from zero to non-zero.
 */
    void
ml_open_files()
{
    buf_T	*buf;

    for (buf = firstbuf; buf != NULL; buf = buf->b_next)
	if (!buf->b_p_ro || buf->b_changed)
	    ml_open_file(buf);
}

/*
 * Open a swap file for an existing memfile, if there is no swap file yet.
 * If we are unable to find a file name, mf_fname will be NULL
 * and the memfile will be in memory only (no recovery possible).
 */
    void
ml_open_file(buf)
    buf_T	*buf;
{
    memfile_T	*mfp;
    char_u	*fname;
    char_u	*dirp;

    mfp = buf->b_ml.ml_mfp;
    if (mfp == NULL || mfp->mf_fd >= 0 || !buf->b_p_swf)
	return;		/* nothing to do */

#ifdef FEAT_SPELL
    /* For a spell buffer use a temp file name. */
    if (buf->b_spell)
    {
	fname = vim_tempname('s');
	if (fname != NULL)
	    (void)mf_open_file(mfp, fname);	/* consumes fname! */
	buf->b_may_swap = FALSE;
	return;
    }
#endif

    /*
     * Try all directories in 'directory' option.
     */
    dirp = p_dir;
    for (;;)
    {
	if (*dirp == NUL)
	    break;
	/* There is a small chance that between chosing the swap file name and
	 * creating it, another Vim creates the file.  In that case the
	 * creation will fail and we will use another directory. */
	fname = findswapname(buf, &dirp, NULL); /* allocates fname */
	if (fname == NULL)
	    continue;
	if (mf_open_file(mfp, fname) == OK)	/* consumes fname! */
	{
#if defined(MSDOS) || defined(MSWIN) || defined(RISCOS)
	    /*
	     * set full pathname for swap file now, because a ":!cd dir" may
	     * change directory without us knowing it.
	     */
	    mf_fullname(mfp);
#endif
	    ml_upd_block0(buf, FALSE);

	    /* Flush block zero, so others can read it */
	    if (mf_sync(mfp, MFS_ZERO) == OK)
	    {
		/* Mark all blocks that should be in the swapfile as dirty.
		 * Needed for when the 'swapfile' option was reset, so that
		 * the swap file was deleted, and then on again. */
		mf_set_dirty(mfp);
		break;
	    }
	    /* Writing block 0 failed: close the file and try another dir */
	    mf_close_file(buf, FALSE);
	}
    }

    if (mfp->mf_fname == NULL)		/* Failed! */
    {
	need_wait_return = TRUE;	/* call wait_return later */
	++no_wait_return;
	(void)EMSG2(_("E303: Unable to open swap file for \"%s\", recovery impossible"),
		    buf_spname(buf) != NULL
			? (char_u *)buf_spname(buf)
			: buf->b_fname);
	--no_wait_return;
    }

    /* don't try to open a swap file again */
    buf->b_may_swap = FALSE;
}

/*
 * If still need to create a swap file, and starting to edit a not-readonly
 * file, or reading into an existing buffer, create a swap file now.
 */
    void
check_need_swap(newfile)
    int	    newfile;		/* reading file into new buffer */
{
    if (curbuf->b_may_swap && (!curbuf->b_p_ro || !newfile))
	ml_open_file(curbuf);
}

/*
 * Close memline for buffer 'buf'.
 * If 'del_file' is TRUE, delete the swap file
 */
    void
ml_close(buf, del_file)
    buf_T	*buf;
    int		del_file;
{
    if (buf->b_ml.ml_mfp == NULL)		/* not open */
	return;
    mf_close(buf->b_ml.ml_mfp, del_file);	/* close the .swp file */
    if (buf->b_ml.ml_line_lnum != 0 && (buf->b_ml.ml_flags & ML_LINE_DIRTY))
	vim_free(buf->b_ml.ml_line_ptr);
    vim_free(buf->b_ml.ml_stack);
#ifdef FEAT_BYTEOFF
    vim_free(buf->b_ml.ml_chunksize);
    buf->b_ml.ml_chunksize = NULL;
#endif
    buf->b_ml.ml_mfp = NULL;

    /* Reset the "recovered" flag, give the ATTENTION prompt the next time
     * this buffer is loaded. */
    buf->b_flags &= ~BF_RECOVERED;
}

/*
 * Close all existing memlines and memfiles.
 * Only used when exiting.
 * When 'del_file' is TRUE, delete the memfiles.
 * But don't delete files that were ":preserve"d when we are POSIX compatible.
 */
    void
ml_close_all(del_file)
    int		del_file;
{
    buf_T	*buf;

    for (buf = firstbuf; buf != NULL; buf = buf->b_next)
	ml_close(buf, del_file && ((buf->b_flags & BF_PRESERVED) == 0
				 || vim_strchr(p_cpo, CPO_PRESERVE) == NULL));
#ifdef TEMPDIRNAMES
    vim_deltempdir();	    /* delete created temp directory */
#endif
}

/*
 * Close all memfiles for not modified buffers.
 * Only use just before exiting!
 */
    void
ml_close_notmod()
{
    buf_T	*buf;

    for (buf = firstbuf; buf != NULL; buf = buf->b_next)
	if (!bufIsChanged(buf))
	    ml_close(buf, TRUE);    /* close all not-modified buffers */
}

/*
 * Update the timestamp in the .swp file.
 * Used when the file has been written.
 */
    void
ml_timestamp(buf)
    buf_T	*buf;
{
    ml_upd_block0(buf, TRUE);
}

/*
 * Update the timestamp or the B0_SAME_DIR flag of the .swp file.
 */
    static void
ml_upd_block0(buf, set_fname)
    buf_T	*buf;
    int		set_fname;
{
    memfile_T	*mfp;
    bhdr_T	*hp;
    ZERO_BL	*b0p;

    mfp = buf->b_ml.ml_mfp;
    if (mfp == NULL || (hp = mf_get(mfp, (blocknr_T)0, 1)) == NULL)
	return;
    b0p = (ZERO_BL *)(hp->bh_data);
    if (b0p->b0_id[0] != BLOCK0_ID0 || b0p->b0_id[1] != BLOCK0_ID1)
	EMSG(_("E304: ml_upd_block0(): Didn't get block 0??"));
    else
    {
	if (set_fname)
	    set_b0_fname(b0p, buf);
	else
	    set_b0_dir_flag(b0p, buf);
    }
    mf_put(mfp, hp, TRUE, FALSE);
}

/*
 * Write file name and timestamp into block 0 of a swap file.
 * Also set buf->b_mtime.
 * Don't use NameBuff[]!!!
 */
    static void
set_b0_fname(b0p, buf)
    ZERO_BL	*b0p;
    buf_T	*buf;
{
    struct stat	st;

    if (buf->b_ffname == NULL)
	b0p->b0_fname[0] = NUL;
    else
    {
#if defined(MSDOS) || defined(MSWIN) || defined(AMIGA) || defined(RISCOS)
	/* Systems that cannot translate "~user" back into a path: copy the
	 * file name unmodified.  Do use slashes instead of backslashes for
	 * portability. */
	vim_strncpy(b0p->b0_fname, buf->b_ffname, B0_FNAME_SIZE - 1);
# ifdef BACKSLASH_IN_FILENAME
	forward_slash(b0p->b0_fname);
# endif
#else
	size_t	flen, ulen;
	char_u	uname[B0_UNAME_SIZE];

	/*
	 * For a file under the home directory of the current user, we try to
	 * replace the home directory path with "~user". This helps when
	 * editing the same file on different machines over a network.
	 * First replace home dir path with "~/" with home_replace().
	 * Then insert the user name to get "~user/".
	 */
	home_replace(NULL, buf->b_ffname, b0p->b0_fname, B0_FNAME_SIZE, TRUE);
	if (b0p->b0_fname[0] == '~')
	{
	    flen = STRLEN(b0p->b0_fname);
	    /* If there is no user name or it is too long, don't use "~/" */
	    if (get_user_name(uname, B0_UNAME_SIZE) == FAIL
			 || (ulen = STRLEN(uname)) + flen > B0_FNAME_SIZE - 1)
		vim_strncpy(b0p->b0_fname, buf->b_ffname, B0_FNAME_SIZE - 1);
	    else
	    {
		mch_memmove(b0p->b0_fname + ulen + 1, b0p->b0_fname + 1, flen);
		mch_memmove(b0p->b0_fname + 1, uname, ulen);
	    }
	}
#endif
	if (mch_stat((char *)buf->b_ffname, &st) >= 0)
	{
	    long_to_char((long)st.st_mtime, b0p->b0_mtime);
#ifdef CHECK_INODE
	    long_to_char((long)st.st_ino, b0p->b0_ino);
#endif
	    buf_store_time(buf, &st, buf->b_ffname);
	    buf->b_mtime_read = buf->b_mtime;
	}
	else
	{
	    long_to_char(0L, b0p->b0_mtime);
#ifdef CHECK_INODE
	    long_to_char(0L, b0p->b0_ino);
#endif
	    buf->b_mtime = 0;
	    buf->b_mtime_read = 0;
	    buf->b_orig_size = 0;
	    buf->b_orig_mode = 0;
	}
    }

#ifdef FEAT_MBYTE
    /* Also add the 'fileencoding' if there is room. */
    add_b0_fenc(b0p, curbuf);
#endif
}

/*
 * Update the B0_SAME_DIR flag of the swap file.  It's set if the file and the
 * swapfile for "buf" are in the same directory.
 * This is fail safe: if we are not sure the directories are equal the flag is
 * not set.
 */
    static void
set_b0_dir_flag(b0p, buf)
    ZERO_BL	*b0p;
    buf_T	*buf;
{
    if (same_directory(buf->b_ml.ml_mfp->mf_fname, buf->b_ffname))
	b0p->b0_flags |= B0_SAME_DIR;
    else
	b0p->b0_flags &= ~B0_SAME_DIR;
}

#ifdef FEAT_MBYTE
/*
 * When there is room, add the 'fileencoding' to block zero.
 */
    static void
add_b0_fenc(b0p, buf)
    ZERO_BL	*b0p;
    buf_T	*buf;
{
    int		n;

    n = (int)STRLEN(buf->b_p_fenc);
    if (STRLEN(b0p->b0_fname) + n + 1 > B0_FNAME_SIZE)
	b0p->b0_flags &= ~B0_HAS_FENC;
    else
    {
	mch_memmove((char *)b0p->b0_fname + B0_FNAME_SIZE - n,
					    (char *)buf->b_p_fenc, (size_t)n);
	*(b0p->b0_fname + B0_FNAME_SIZE - n - 1) = NUL;
	b0p->b0_flags |= B0_HAS_FENC;
    }
}
#endif


/*
 * try to recover curbuf from the .swp file
 */
    void
ml_recover()
{
    buf_T	*buf = NULL;
    memfile_T	*mfp = NULL;
    char_u	*fname;
    bhdr_T	*hp = NULL;
    ZERO_BL	*b0p;
    int		b0_ff;
    char_u	*b0_fenc = NULL;
    PTR_BL	*pp;
    DATA_BL	*dp;
    infoptr_T	*ip;
    blocknr_T	bnum;
    int		page_count;
    struct stat	org_stat, swp_stat;
    int		len;
    int		directly;
    linenr_T	lnum;
    char_u	*p;
    int		i;
    long	error;
    int		cannot_open;
    linenr_T	line_count;
    int		has_error;
    int		idx;
    int		top;
    int		txt_start;
    off_t	size;
    int		called_from_main;
    int		serious_error = TRUE;
    long	mtime;
    int		attr;

    recoverymode = TRUE;
    called_from_main = (curbuf->b_ml.ml_mfp == NULL);
    attr = hl_attr(HLF_E);
/*
 * If the file name ends in ".sw?" we use it directly.
 * Otherwise a search is done to find the swap file(s).
 */
    fname = curbuf->b_fname;
    if (fname == NULL)		    /* When there is no file name */
	fname = (char_u *)"";
    len = (int)STRLEN(fname);
    if (len >= 4 &&
#if defined(VMS) || defined(RISCOS)
	    STRNICMP(fname + len - 4, "_sw" , 3)
#else
	    STRNICMP(fname + len - 4, ".sw" , 3)
#endif
		== 0)
    {
	directly = TRUE;
	fname = vim_strsave(fname); /* make a copy for mf_open() */
    }
    else
    {
	directly = FALSE;

	/* count the number of matching swap files */
	len = recover_names(&fname, FALSE, 0);
	if (len == 0)		    /* no swap files found */
	{
	    EMSG2(_("E305: No swap file found for %s"), fname);
	    goto theend;
	}
	if (len == 1)		    /* one swap file found, use it */
	    i = 1;
	else			    /* several swap files found, choose */
	{
	    /* list the names of the swap files */
	    (void)recover_names(&fname, TRUE, 0);
	    msg_putchar('\n');
	    MSG_PUTS(_("Enter number of swap file to use (0 to quit): "));
	    i = get_number(FALSE, NULL);
	    if (i < 1 || i > len)
		goto theend;
	}
	/* get the swap file name that will be used */
	(void)recover_names(&fname, FALSE, i);
    }
    if (fname == NULL)
	goto theend;			/* out of memory */

    /* When called from main() still need to initialize storage structure */
    if (called_from_main && ml_open(curbuf) == FAIL)
	getout(1);

/*
 * allocate a buffer structure (only the memline in it is really used)
 */
    buf = (buf_T *)alloc((unsigned)sizeof(buf_T));
    if (buf == NULL)
    {
	vim_free(fname);
	goto theend;
    }

/*
 * init fields in memline struct
 */
    buf->b_ml.ml_stack_size = 0;	/* no stack yet */
    buf->b_ml.ml_stack = NULL;		/* no stack yet */
    buf->b_ml.ml_stack_top = 0;		/* nothing in the stack */
    buf->b_ml.ml_line_lnum = 0;		/* no cached line */
    buf->b_ml.ml_locked = NULL;		/* no locked block */
    buf->b_ml.ml_flags = 0;

/*
 * open the memfile from the old swap file
 */
    p = vim_strsave(fname);		/* save fname for the message
					   (mf_open() may free fname) */
    mfp = mf_open(fname, O_RDONLY);	/* consumes fname! */
    if (mfp == NULL || mfp->mf_fd < 0)
    {
	if (p != NULL)
	{
	    EMSG2(_("E306: Cannot open %s"), p);
	    vim_free(p);
	}
	goto theend;
    }
    vim_free(p);
    buf->b_ml.ml_mfp = mfp;

    /*
     * The page size set in mf_open() might be different from the page size
     * used in the swap file, we must get it from block 0.  But to read block
     * 0 we need a page size.  Use the minimal size for block 0 here, it will
     * be set to the real value below.
     */
    mfp->mf_page_size = MIN_SWAP_PAGE_SIZE;

/*
 * try to read block 0
 */
    if ((hp = mf_get(mfp, (blocknr_T)0, 1)) == NULL)
    {
	msg_start();
	MSG_PUTS_ATTR(_("Unable to read block 0 from "), attr | MSG_HIST);
	msg_outtrans_attr(mfp->mf_fname, attr | MSG_HIST);
	MSG_PUTS_ATTR(
	   _("\nMaybe no changes were made or Vim did not update the swap file."),
		attr | MSG_HIST);
	msg_end();
	goto theend;
    }
    b0p = (ZERO_BL *)(hp->bh_data);
    if (STRNCMP(b0p->b0_version, "VIM 3.0", 7) == 0)
    {
	msg_start();
	msg_outtrans_attr(mfp->mf_fname, MSG_HIST);
	MSG_PUTS_ATTR(_(" cannot be used with this version of Vim.\n"),
								    MSG_HIST);
	MSG_PUTS_ATTR(_("Use Vim version 3.0.\n"), MSG_HIST);
	msg_end();
	goto theend;
    }
    if (b0p->b0_id[0] != BLOCK0_ID0 || b0p->b0_id[1] != BLOCK0_ID1)
    {
	EMSG2(_("E307: %s does not look like a Vim swap file"), mfp->mf_fname);
	goto theend;
    }
    if (b0_magic_wrong(b0p))
    {
	msg_start();
	msg_outtrans_attr(mfp->mf_fname, attr | MSG_HIST);
#if defined(MSDOS) || defined(MSWIN)
	if (STRNCMP(b0p->b0_hname, "PC ", 3) == 0)
	    MSG_PUTS_ATTR(_(" cannot be used with this version of Vim.\n"),
							     attr | MSG_HIST);
	else
#endif
	    MSG_PUTS_ATTR(_(" cannot be used on this computer.\n"),
							     attr | MSG_HIST);
	MSG_PUTS_ATTR(_("The file was created on "), attr | MSG_HIST);
	/* avoid going past the end of a currupted hostname */
	b0p->b0_fname[0] = NUL;
	MSG_PUTS_ATTR(b0p->b0_hname, attr | MSG_HIST);
	MSG_PUTS_ATTR(_(",\nor the file has been damaged."), attr | MSG_HIST);
	msg_end();
	goto theend;
    }

    /*
     * If we guessed the wrong page size, we have to recalculate the
     * highest block number in the file.
     */
    if (mfp->mf_page_size != (unsigned)char_to_long(b0p->b0_page_size))
    {
	unsigned previous_page_size = mfp->mf_page_size;

	mf_new_page_size(mfp, (unsigned)char_to_long(b0p->b0_page_size));
	if (mfp->mf_page_size < previous_page_size)
	{
	    msg_start();
	    msg_outtrans_attr(mfp->mf_fname, attr | MSG_HIST);
	    MSG_PUTS_ATTR(_(" has been damaged (page size is smaller than minimum value).\n"),
			attr | MSG_HIST);
	    msg_end();
	    goto theend;
	}
	if ((size = lseek(mfp->mf_fd, (off_t)0L, SEEK_END)) <= 0)
	    mfp->mf_blocknr_max = 0;	    /* no file or empty file */
	else
	    mfp->mf_blocknr_max = (blocknr_T)(size / mfp->mf_page_size);
	mfp->mf_infile_count = mfp->mf_blocknr_max;

	/* need to reallocate the memory used to store the data */
	p = alloc(mfp->mf_page_size);
	if (p == NULL)
	    goto theend;
	mch_memmove(p, hp->bh_data, previous_page_size);
	vim_free(hp->bh_data);
	hp->bh_data = p;
	b0p = (ZERO_BL *)(hp->bh_data);
    }

/*
 * If .swp file name given directly, use name from swap file for buffer.
 */
    if (directly)
    {
	expand_env(b0p->b0_fname, NameBuff, MAXPATHL);
	if (setfname(curbuf, NameBuff, NULL, TRUE) == FAIL)
	    goto theend;
    }

    home_replace(NULL, mfp->mf_fname, NameBuff, MAXPATHL, TRUE);
    smsg((char_u *)_("Using swap file \"%s\""), NameBuff);

    if (buf_spname(curbuf) != NULL)
	STRCPY(NameBuff, buf_spname(curbuf));
    else
	home_replace(NULL, curbuf->b_ffname, NameBuff, MAXPATHL, TRUE);
    smsg((char_u *)_("Original file \"%s\""), NameBuff);
    msg_putchar('\n');

/*
 * check date of swap file and original file
 */
    mtime = char_to_long(b0p->b0_mtime);
    if (curbuf->b_ffname != NULL
	    && mch_stat((char *)curbuf->b_ffname, &org_stat) != -1
	    && ((mch_stat((char *)mfp->mf_fname, &swp_stat) != -1
		    && org_stat.st_mtime > swp_stat.st_mtime)
		|| org_stat.st_mtime != mtime))
    {
	EMSG(_("E308: Warning: Original file may have been changed"));
    }
    out_flush();

    /* Get the 'fileformat' and 'fileencoding' from block zero. */
    b0_ff = (b0p->b0_flags & B0_FF_MASK);
    if (b0p->b0_flags & B0_HAS_FENC)
    {
	for (p = b0p->b0_fname + B0_FNAME_SIZE;
				       p > b0p->b0_fname && p[-1] != NUL; --p)
	    ;
	b0_fenc = vim_strnsave(p, (int)(b0p->b0_fname + B0_FNAME_SIZE - p));
    }

    mf_put(mfp, hp, FALSE, FALSE);	/* release block 0 */
    hp = NULL;

    /*
     * Now that we are sure that the file is going to be recovered, clear the
     * contents of the current buffer.
     */
    while (!(curbuf->b_ml.ml_flags & ML_EMPTY))
	ml_delete((linenr_T)1, FALSE);

    /*
     * Try reading the original file to obtain the values of 'fileformat',
     * 'fileencoding', etc.  Ignore errors.  The text itself is not used.
     */
    if (curbuf->b_ffname != NULL)
    {
	(void)readfile(curbuf->b_ffname, NULL, (linenr_T)0,
			      (linenr_T)0, (linenr_T)MAXLNUM, NULL, READ_NEW);
	while (!(curbuf->b_ml.ml_flags & ML_EMPTY))
	    ml_delete((linenr_T)1, FALSE);
    }

    /* Use the 'fileformat' and 'fileencoding' as stored in the swap file. */
    if (b0_ff != 0)
	set_fileformat(b0_ff - 1, OPT_LOCAL);
    if (b0_fenc != NULL)
    {
	set_option_value((char_u *)"fenc", 0L, b0_fenc, OPT_LOCAL);
	vim_free(b0_fenc);
    }
    unchanged(curbuf, TRUE);

    bnum = 1;		/* start with block 1 */
    page_count = 1;	/* which is 1 page */
    lnum = 0;		/* append after line 0 in curbuf */
    line_count = 0;
    idx = 0;		/* start with first index in block 1 */
    error = 0;
    buf->b_ml.ml_stack_top = 0;
    buf->b_ml.ml_stack = NULL;
    buf->b_ml.ml_stack_size = 0;	/* no stack yet */

    if (curbuf->b_ffname == NULL)
	cannot_open = TRUE;
    else
	cannot_open = FALSE;

    serious_error = FALSE;
    for ( ; !got_int; line_breakcheck())
    {
	if (hp != NULL)
	    mf_put(mfp, hp, FALSE, FALSE);	/* release previous block */

	/*
	 * get block
	 */
	if ((hp = mf_get(mfp, (blocknr_T)bnum, page_count)) == NULL)
	{
	    if (bnum == 1)
	    {
		EMSG2(_("E309: Unable to read block 1 from %s"), mfp->mf_fname);
		goto theend;
	    }
	    ++error;
	    ml_append(lnum++, (char_u *)_("???MANY LINES MISSING"),
							    (colnr_T)0, TRUE);
	}
	else		/* there is a block */
	{
	    pp = (PTR_BL *)(hp->bh_data);
	    if (pp->pb_id == PTR_ID)		/* it is a pointer block */
	    {
		/* check line count when using pointer block first time */
		if (idx == 0 && line_count != 0)
		{
		    for (i = 0; i < (int)pp->pb_count; ++i)
			line_count -= pp->pb_pointer[i].pe_line_count;
		    if (line_count != 0)
		    {
			++error;
			ml_append(lnum++, (char_u *)_("???LINE COUNT WRONG"),
							    (colnr_T)0, TRUE);
		    }
		}

		if (pp->pb_count == 0)
		{
		    ml_append(lnum++, (char_u *)_("???EMPTY BLOCK"),
							    (colnr_T)0, TRUE);
		    ++error;
		}
		else if (idx < (int)pp->pb_count)	/* go a block deeper */
		{
		    if (pp->pb_pointer[idx].pe_bnum < 0)
		    {
			/*
			 * Data block with negative block number.
			 * Try to read lines from the original file.
			 * This is slow, but it works.
			 */
			if (!cannot_open)
			{
			    line_count = pp->pb_pointer[idx].pe_line_count;
			    if (readfile(curbuf->b_ffname, NULL, lnum,
					pp->pb_pointer[idx].pe_old_lnum - 1,
					line_count, NULL, 0) == FAIL)
				cannot_open = TRUE;
			    else
				lnum += line_count;
			}
			if (cannot_open)
			{
			    ++error;
			    ml_append(lnum++, (char_u *)_("???LINES MISSING"),
							    (colnr_T)0, TRUE);
			}
			++idx;	    /* get same block again for next index */
			continue;
		    }

		    /*
		     * going one block deeper in the tree
		     */
		    if ((top = ml_add_stack(buf)) < 0)	/* new entry in stack */
		    {
			++error;
			break;		    /* out of memory */
		    }
		    ip = &(buf->b_ml.ml_stack[top]);
		    ip->ip_bnum = bnum;
		    ip->ip_index = idx;

		    bnum = pp->pb_pointer[idx].pe_bnum;
		    line_count = pp->pb_pointer[idx].pe_line_count;
		    page_count = pp->pb_pointer[idx].pe_page_count;
		    continue;
		}
	    }
	    else	    /* not a pointer block */
	    {
		dp = (DATA_BL *)(hp->bh_data);
		if (dp->db_id != DATA_ID)	/* block id wrong */
		{
		    if (bnum == 1)
		    {
			EMSG2(_("E310: Block 1 ID wrong (%s not a .swp file?)"),
							       mfp->mf_fname);
			goto theend;
		    }
		    ++error;
		    ml_append(lnum++, (char_u *)_("???BLOCK MISSING"),
							    (colnr_T)0, TRUE);
		}
		else
		{
		    /*
		     * it is a data block
		     * Append all the lines in this block
		     */
		    has_error = FALSE;
			/*
			 * check length of block
			 * if wrong, use length in pointer block
			 */
		    if (page_count * mfp->mf_page_size != dp->db_txt_end)
		    {
			ml_append(lnum++, (char_u *)_("??? from here until ???END lines may be messed up"),
							    (colnr_T)0, TRUE);
			++error;
			has_error = TRUE;
			dp->db_txt_end = page_count * mfp->mf_page_size;
		    }

			/* make sure there is a NUL at the end of the block */
		    *((char_u *)dp + dp->db_txt_end - 1) = NUL;

			/*
			 * check number of lines in block
			 * if wrong, use count in data block
			 */
		    if (line_count != dp->db_line_count)
		    {
			ml_append(lnum++, (char_u *)_("??? from here until ???END lines may have been inserted/deleted"),
							    (colnr_T)0, TRUE);
			++error;
			has_error = TRUE;
		    }

		    for (i = 0; i < dp->db_line_count; ++i)
		    {
			txt_start = (dp->db_index[i] & DB_INDEX_MASK);
			if (txt_start <= HEADER_SIZE
					  || txt_start >= (int)dp->db_txt_end)
			{
			    p = (char_u *)"???";
			    ++error;
			}
			else
			    p = (char_u *)dp + txt_start;
			ml_append(lnum++, p, (colnr_T)0, TRUE);
		    }
		    if (has_error)
			ml_append(lnum++, (char_u *)_("???END"), (colnr_T)0, TRUE);
		}
	    }
	}

	if (buf->b_ml.ml_stack_top == 0)	/* finished */
	    break;

	/*
	 * go one block up in the tree
	 */
	ip = &(buf->b_ml.ml_stack[--(buf->b_ml.ml_stack_top)]);
	bnum = ip->ip_bnum;
	idx = ip->ip_index + 1;	    /* go to next index */
	page_count = 1;
    }

    /*
     * The dummy line from the empty buffer will now be after the last line in
     * the buffer. Delete it.
     */
    ml_delete(curbuf->b_ml.ml_line_count, FALSE);
    curbuf->b_flags |= BF_RECOVERED;

    recoverymode = FALSE;
    if (got_int)
	EMSG(_("E311: Recovery Interrupted"));
    else if (error)
    {
	++no_wait_return;
	MSG(">>>>>>>>>>>>>");
	EMSG(_("E312: Errors detected while recovering; look for lines starting with ???"));
	--no_wait_return;
	MSG(_("See \":help E312\" for more information."));
	MSG(">>>>>>>>>>>>>");
    }
    else
    {
	MSG(_("Recovery completed. You should check if everything is OK."));
	MSG_PUTS(_("\n(You might want to write out this file under another name\n"));
	MSG_PUTS(_("and run diff with the original file to check for changes)\n"));
	MSG_PUTS(_("Delete the .swp file afterwards.\n\n"));
	cmdline_row = msg_row;
    }
    redraw_curbuf_later(NOT_VALID);

theend:
    recoverymode = FALSE;
    if (mfp != NULL)
    {
	if (hp != NULL)
	    mf_put(mfp, hp, FALSE, FALSE);
	mf_close(mfp, FALSE);	    /* will also vim_free(mfp->mf_fname) */
    }
    if (buf != NULL)
    {
	vim_free(buf->b_ml.ml_stack);
	vim_free(buf);
    }
    if (serious_error && called_from_main)
	ml_close(curbuf, TRUE);
#ifdef FEAT_AUTOCMD
    else
    {
	apply_autocmds(EVENT_BUFREADPOST, NULL, curbuf->b_fname, FALSE, curbuf);
	apply_autocmds(EVENT_BUFWINENTER, NULL, curbuf->b_fname, FALSE, curbuf);
    }
#endif
    return;
}

/*
 * Find the names of swap files in current directory and the directory given
 * with the 'directory' option.
 *
 * Used to:
 * - list the swap files for "vim -r"
 * - count the number of swap files when recovering
 * - list the swap files when recovering
 * - find the name of the n'th swap file when recovering
 */
    int
recover_names(fname, list, nr)
    char_u	**fname;    /* base for swap file name */
    int		list;	    /* when TRUE, list the swap file names */
    int		nr;	    /* when non-zero, return nr'th swap file name */
{
    int		num_names;
    char_u	*(names[6]);
    char_u	*tail;
    char_u	*p;
    int		num_files;
    int		file_count = 0;
    char_u	**files;
    int		i;
    char_u	*dirp;
    char_u	*dir_name;

    if (list)
    {
	    /* use msg() to start the scrolling properly */
	msg((char_u *)_("Swap files found:"));
	msg_putchar('\n');
    }

    /*
     * Do the loop for every directory in 'directory'.
     * First allocate some memory to put the directory name in.
     */
    dir_name = alloc((unsigned)STRLEN(p_dir) + 1);
    dirp = p_dir;
    while (dir_name != NULL && *dirp)
    {
	/*
	 * Isolate a directory name from *dirp and put it in dir_name (we know
	 * it is large enough, so use 31000 for length).
	 * Advance dirp to next directory name.
	 */
	(void)copy_option_part(&dirp, dir_name, 31000, ",");

	if (dir_name[0] == '.' && dir_name[1] == NUL)	/* check current dir */
	{
	    if (fname == NULL || *fname == NULL)
	    {
#ifdef VMS
		names[0] = vim_strsave((char_u *)"*_sw%");
#else
# ifdef RISCOS
		names[0] = vim_strsave((char_u *)"*_sw#");
# else
		names[0] = vim_strsave((char_u *)"*.sw?");
# endif
#endif
#if defined(UNIX) || defined(WIN3264)
		/* For Unix names starting with a dot are special.  MS-Windows
		 * supports this too, on some file systems. */
		names[1] = vim_strsave((char_u *)".*.sw?");
		names[2] = vim_strsave((char_u *)".sw?");
		num_names = 3;
#else
# ifdef VMS
		names[1] = vim_strsave((char_u *)".*_sw%");
		num_names = 2;
# else
		num_names = 1;
# endif
#endif
	    }
	    else
		num_names = recov_file_names(names, *fname, TRUE);
	}
	else			    /* check directory dir_name */
	{
	    if (fname == NULL || *fname == NULL)
	    {
#ifdef VMS
		names[0] = concat_fnames(dir_name, (char_u *)"*_sw%", TRUE);
#else
# ifdef RISCOS
		names[0] = concat_fnames(dir_name, (char_u *)"*_sw#", TRUE);
# else
		names[0] = concat_fnames(dir_name, (char_u *)"*.sw?", TRUE);
# endif
#endif
#if defined(UNIX) || defined(WIN3264)
		/* For Unix names starting with a dot are special.  MS-Windows
		 * supports this too, on some file systems. */
		names[1] = concat_fnames(dir_name, (char_u *)".*.sw?", TRUE);
		names[2] = concat_fnames(dir_name, (char_u *)".sw?", TRUE);
		num_names = 3;
#else
# ifdef VMS
		names[1] = concat_fnames(dir_name, (char_u *)".*_sw%", TRUE);
		num_names = 2;
# else
		num_names = 1;
# endif
#endif
	    }
	    else
	    {
#if defined(UNIX) || defined(WIN3264)
		p = dir_name + STRLEN(dir_name);
		if (after_pathsep(dir_name, p) && p[-1] == p[-2])
		{
		    /* Ends with '//', Use Full path for swap name */
		    tail = make_percent_swname(dir_name, *fname);
		}
		else
#endif
		{
		    tail = gettail(*fname);
		    tail = concat_fnames(dir_name, tail, TRUE);
		}
		if (tail == NULL)
		    num_names = 0;
		else
		{
		    num_names = recov_file_names(names, tail, FALSE);
		    vim_free(tail);
		}
	    }
	}

	    /* check for out-of-memory */
	for (i = 0; i < num_names; ++i)
	{
	    if (names[i] == NULL)
	    {
		for (i = 0; i < num_names; ++i)
		    vim_free(names[i]);
		num_names = 0;
	    }
	}
	if (num_names == 0)
	    num_files = 0;
	else if (expand_wildcards(num_names, names, &num_files, &files,
					EW_KEEPALL|EW_FILE|EW_SILENT) == FAIL)
	    num_files = 0;

	/*
	 * When no swap file found, wildcard expansion might have failed (e.g.
	 * not able to execute the shell).
	 * Try finding a swap file by simply adding ".swp" to the file name.
	 */
	if (*dirp == NUL && file_count + num_files == 0
					   && fname != NULL && *fname != NULL)
	{
	    struct stat	    st;
	    char_u	    *swapname;

#if defined(VMS) || defined(RISCOS)
	    swapname = modname(*fname, (char_u *)"_swp", FALSE);
#else
	    swapname = modname(*fname, (char_u *)".swp", TRUE);
#endif
	    if (swapname != NULL)
	    {
		if (mch_stat((char *)swapname, &st) != -1)	    /* It exists! */
		{
		    files = (char_u **)alloc((unsigned)sizeof(char_u *));
		    if (files != NULL)
		    {
			files[0] = swapname;
			swapname = NULL;
			num_files = 1;
		    }
		}
		vim_free(swapname);
	    }
	}

	/*
	 * remove swapfile name of the current buffer, it must be ignored
	 */
	if (curbuf->b_ml.ml_mfp != NULL
			       && (p = curbuf->b_ml.ml_mfp->mf_fname) != NULL)
	{
	    for (i = 0; i < num_files; ++i)
		if (fullpathcmp(p, files[i], TRUE) & FPC_SAME)
		{
		    vim_free(files[i]);
		    --num_files;
		    for ( ; i < num_files; ++i)
			files[i] = files[i + 1];
		}
	}
	if (nr > 0)
	{
	    file_count += num_files;
	    if (nr <= file_count)
	    {
		*fname = vim_strsave(files[nr - 1 + num_files - file_count]);
		dirp = (char_u *)"";		    /* stop searching */
	    }
	}
	else if (list)
	{
	    if (dir_name[0] == '.' && dir_name[1] == NUL)
	    {
		if (fname == NULL || *fname == NULL)
		    MSG_PUTS(_("   In current directory:\n"));
		else
		    MSG_PUTS(_("   Using specified name:\n"));
	    }
	    else
	    {
		MSG_PUTS(_("   In directory "));
		msg_home_replace(dir_name);
		MSG_PUTS(":\n");
	    }

	    if (num_files)
	    {
		for (i = 0; i < num_files; ++i)
		{
		    /* print the swap file name */
		    msg_outnum((long)++file_count);
		    MSG_PUTS(".    ");
		    msg_puts(gettail(files[i]));
		    msg_putchar('\n');
		    (void)swapfile_info(files[i]);
		}
	    }
	    else
		MSG_PUTS(_("      -- none --\n"));
	    out_flush();
	}
	else
	    file_count += num_files;

	for (i = 0; i < num_names; ++i)
	    vim_free(names[i]);
	if (num_files > 0)
	    FreeWild(num_files, files);
    }
    vim_free(dir_name);
    return file_count;
}

#if defined(UNIX) || defined(WIN3264)  /* Need _very_ long file names */
/*
 * Append the full path to name with path separators made into percent
 * signs, to dir. An unnamed buffer is handled as "" (<currentdir>/"")
 */
    static char_u *
make_percent_swname(dir, name)
    char_u	*dir;
    char_u	*name;
{
    char_u *d, *s, *f;

    f = fix_fname(name != NULL ? name : (char_u *) "");
    d = NULL;
    if (f != NULL)
    {
	s = alloc((unsigned)(STRLEN(f) + 1));
	if (s != NULL)
	{
	    STRCPY(s, f);
	    for (d = s; *d != NUL; mb_ptr_adv(d))
		if (vim_ispathsep(*d))
		    *d = '%';
	    d = concat_fnames(dir, s, TRUE);
	    vim_free(s);
	}
	vim_free(f);
    }
    return d;
}
#endif

#if (defined(UNIX) || defined(__EMX__) || defined(VMS)) && (defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG))
static int process_still_running;
#endif

/*
 * Give information about an existing swap file.
 * Returns timestamp (0 when unknown).
 */
    static time_t
swapfile_info(fname)
    char_u	*fname;
{
    struct stat	    st;
    int		    fd;
    struct block0   b0;
    time_t	    x = (time_t)0;
    char	    *p;
#ifdef UNIX
    char_u	    uname[B0_UNAME_SIZE];
#endif

    /* print the swap file date */
    if (mch_stat((char *)fname, &st) != -1)
    {
#ifdef UNIX
	/* print name of owner of the file */
	if (mch_get_uname(st.st_uid, uname, B0_UNAME_SIZE) == OK)
	{
	    MSG_PUTS(_("          owned by: "));
	    msg_outtrans(uname);
	    MSG_PUTS(_("   dated: "));
	}
	else
#endif
	    MSG_PUTS(_("             dated: "));
	x = st.st_mtime;		    /* Manx C can't do &st.st_mtime */
	p = ctime(&x);			    /* includes '\n' */
	if (p == NULL)
	    MSG_PUTS("(invalid)\n");
	else
	    MSG_PUTS(p);
    }

    /*
     * print the original file name
     */
    fd = mch_open((char *)fname, O_RDONLY | O_EXTRA, 0);
    if (fd >= 0)
    {
	if (read(fd, (char *)&b0, sizeof(b0)) == sizeof(b0))
	{
	    if (STRNCMP(b0.b0_version, "VIM 3.0", 7) == 0)
	    {
		MSG_PUTS(_("         [from Vim version 3.0]"));
	    }
	    else if (b0.b0_id[0] != BLOCK0_ID0 || b0.b0_id[1] != BLOCK0_ID1)
	    {
		MSG_PUTS(_("         [does not look like a Vim swap file]"));
	    }
	    else
	    {
		MSG_PUTS(_("         file name: "));
		if (b0.b0_fname[0] == NUL)
		    MSG_PUTS(_("[No Name]"));
		else
		    msg_outtrans(b0.b0_fname);

		MSG_PUTS(_("\n          modified: "));
		MSG_PUTS(b0.b0_dirty ? _("YES") : _("no"));

		if (*(b0.b0_uname) != NUL)
		{
		    MSG_PUTS(_("\n         user name: "));
		    msg_outtrans(b0.b0_uname);
		}

		if (*(b0.b0_hname) != NUL)
		{
		    if (*(b0.b0_uname) != NUL)
			MSG_PUTS(_("   host name: "));
		    else
			MSG_PUTS(_("\n         host name: "));
		    msg_outtrans(b0.b0_hname);
		}

		if (char_to_long(b0.b0_pid) != 0L)
		{
		    MSG_PUTS(_("\n        process ID: "));
		    msg_outnum(char_to_long(b0.b0_pid));
#if defined(UNIX) || defined(__EMX__)
		    /* EMX kill() not working correctly, it seems */
		    if (kill((pid_t)char_to_long(b0.b0_pid), 0) == 0)
		    {
			MSG_PUTS(_(" (still running)"));
# if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
			process_still_running = TRUE;
# endif
		    }
#endif
		}

		if (b0_magic_wrong(&b0))
		{
#if defined(MSDOS) || defined(MSWIN)
		    if (STRNCMP(b0.b0_hname, "PC ", 3) == 0)
			MSG_PUTS(_("\n         [not usable with this version of Vim]"));
		    else
#endif
			MSG_PUTS(_("\n         [not usable on this computer]"));
		}
	    }
	}
	else
	    MSG_PUTS(_("         [cannot be read]"));
	close(fd);
    }
    else
	MSG_PUTS(_("         [cannot be opened]"));
    msg_putchar('\n');

    return x;
}

    static int
recov_file_names(names, path, prepend_dot)
    char_u	**names;
    char_u	*path;
    int		prepend_dot;
{
    int		num_names;

#ifdef SHORT_FNAME
    /*
     * (MS-DOS) always short names
     */
    names[0] = modname(path, (char_u *)".sw?", FALSE);
    num_names = 1;
#else /* !SHORT_FNAME */
    /*
     * (Win32 and Win64) never short names, but do prepend a dot.
     * (Not MS-DOS or Win32 or Win64) maybe short name, maybe not: Try both.
     * Only use the short name if it is different.
     */
    char_u	*p;
    int		i;
# ifndef WIN3264
    int	    shortname = curbuf->b_shortname;

    curbuf->b_shortname = FALSE;
# endif

    num_names = 0;

    /*
     * May also add the file name with a dot prepended, for swap file in same
     * dir as original file.
     */
    if (prepend_dot)
    {
	names[num_names] = modname(path, (char_u *)".sw?", TRUE);
	if (names[num_names] == NULL)
	    goto end;
	++num_names;
    }

    /*
     * Form the normal swap file name pattern by appending ".sw?".
     */
#ifdef VMS
    names[num_names] = concat_fnames(path, (char_u *)"_sw%", FALSE);
#else
# ifdef RISCOS
    names[num_names] = concat_fnames(path, (char_u *)"_sw#", FALSE);
# else
    names[num_names] = concat_fnames(path, (char_u *)".sw?", FALSE);
# endif
#endif
    if (names[num_names] == NULL)
	goto end;
    if (num_names >= 1)	    /* check if we have the same name twice */
    {
	p = names[num_names - 1];
	i = (int)STRLEN(names[num_names - 1]) - (int)STRLEN(names[num_names]);
	if (i > 0)
	    p += i;	    /* file name has been expanded to full path */

	if (STRCMP(p, names[num_names]) != 0)
	    ++num_names;
	else
	    vim_free(names[num_names]);
    }
    else
	++num_names;

# ifndef WIN3264
    /*
     * Also try with 'shortname' set, in case the file is on a DOS filesystem.
     */
    curbuf->b_shortname = TRUE;
#ifdef VMS
    names[num_names] = modname(path, (char_u *)"_sw%", FALSE);
#else
# ifdef RISCOS
    names[num_names] = modname(path, (char_u *)"_sw#", FALSE);
# else
    names[num_names] = modname(path, (char_u *)".sw?", FALSE);
# endif
#endif
    if (names[num_names] == NULL)
	goto end;

    /*
     * Remove the one from 'shortname', if it's the same as with 'noshortname'.
     */
    p = names[num_names];
    i = STRLEN(names[num_names]) - STRLEN(names[num_names - 1]);
    if (i > 0)
	p += i;		/* file name has been expanded to full path */
    if (STRCMP(names[num_names - 1], p) == 0)
	vim_free(names[num_names]);
    else
	++num_names;
# endif

end:
# ifndef WIN3264
    curbuf->b_shortname = shortname;
# endif

#endif /* !SHORT_FNAME */

    return num_names;
}

/*
 * sync all memlines
 *
 * If 'check_file' is TRUE, check if original file exists and was not changed.
 * If 'check_char' is TRUE, stop syncing when character becomes available, but
 * always sync at least one block.
 */
    void
ml_sync_all(check_file, check_char)
    int	    check_file;
    int	    check_char;
{
    buf_T		*buf;
    struct stat		st;

    for (buf = firstbuf; buf != NULL; buf = buf->b_next)
    {
	if (buf->b_ml.ml_mfp == NULL || buf->b_ml.ml_mfp->mf_fname == NULL)
	    continue;			    /* no file */

	ml_flush_line(buf);		    /* flush buffered line */
					    /* flush locked block */
	(void)ml_find_line(buf, (linenr_T)0, ML_FLUSH);
	if (bufIsChanged(buf) && check_file && mf_need_trans(buf->b_ml.ml_mfp)
						     && buf->b_ffname != NULL)
	{
	    /*
	     * If the original file does not exist anymore or has been changed
	     * call ml_preserve() to get rid of all negative numbered blocks.
	     */
	    if (mch_stat((char *)buf->b_ffname, &st) == -1
		    || st.st_mtime != buf->b_mtime_read
		    || (size_t)st.st_size != buf->b_orig_size)
	    {
		ml_preserve(buf, FALSE);
		did_check_timestamps = FALSE;
		need_check_timestamps = TRUE;	/* give message later */
	    }
	}
	if (buf->b_ml.ml_mfp->mf_dirty)
	{
	    (void)mf_sync(buf->b_ml.ml_mfp, (check_char ? MFS_STOP : 0)
					| (bufIsChanged(buf) ? MFS_FLUSH : 0));
	    if (check_char && ui_char_avail())	/* character available now */
		break;
	}
    }
}

/*
 * sync one buffer, including negative blocks
 *
 * after this all the blocks are in the swap file
 *
 * Used for the :preserve command and when the original file has been
 * changed or deleted.
 *
 * when message is TRUE the success of preserving is reported
 */
    void
ml_preserve(buf, message)
    buf_T	*buf;
    int		message;
{
    bhdr_T	*hp;
    linenr_T	lnum;
    memfile_T	*mfp = buf->b_ml.ml_mfp;
    int		status;
    int		got_int_save = got_int;

    if (mfp == NULL || mfp->mf_fname == NULL)
    {
	if (message)
	    EMSG(_("E313: Cannot preserve, there is no swap file"));
	return;
    }

    /* We only want to stop when interrupted here, not when interrupted
     * before. */
    got_int = FALSE;

    ml_flush_line(buf);				    /* flush buffered line */
    (void)ml_find_line(buf, (linenr_T)0, ML_FLUSH); /* flush locked block */
    status = mf_sync(mfp, MFS_ALL | MFS_FLUSH);

    /* stack is invalid after mf_sync(.., MFS_ALL) */
    buf->b_ml.ml_stack_top = 0;

    /*
     * Some of the data blocks may have been changed from negative to
     * positive block number. In that case the pointer blocks need to be
     * updated.
     *
     * We don't know in which pointer block the references are, so we visit
     * all data blocks until there are no more translations to be done (or
     * we hit the end of the file, which can only happen in case a write fails,
     * e.g. when file system if full).
     * ml_find_line() does the work by translating the negative block numbers
     * when getting the first line of each data block.
     */
    if (mf_need_trans(mfp) && !got_int)
    {
	lnum = 1;
	while (mf_need_trans(mfp) && lnum <= buf->b_ml.ml_line_count)
	{
	    hp = ml_find_line(buf, lnum, ML_FIND);
	    if (hp == NULL)
	    {
		status = FAIL;
		goto theend;
	    }
	    CHECK(buf->b_ml.ml_locked_low != lnum, "low != lnum");
	    lnum = buf->b_ml.ml_locked_high + 1;
	}
	(void)ml_find_line(buf, (linenr_T)0, ML_FLUSH);	/* flush locked block */
	/* sync the updated pointer blocks */
	if (mf_sync(mfp, MFS_ALL | MFS_FLUSH) == FAIL)
	    status = FAIL;
	buf->b_ml.ml_stack_top = 0;	    /* stack is invalid now */
    }
theend:
    got_int |= got_int_save;

    if (message)
    {
	if (status == OK)
	    MSG(_("File preserved"));
	else
	    EMSG(_("E314: Preserve failed"));
    }
}

/*
 * NOTE: The pointer returned by the ml_get_*() functions only remains valid
 * until the next call!
 *  line1 = ml_get(1);
 *  line2 = ml_get(2);	// line1 is now invalid!
 * Make a copy of the line if necessary.
 */
/*
 * get a pointer to a (read-only copy of a) line
 *
 * On failure an error message is given and IObuff is returned (to avoid
 * having to check for error everywhere).
 */
    char_u  *
ml_get(lnum)
    linenr_T	lnum;
{
    return ml_get_buf(curbuf, lnum, FALSE);
}

/*
 * ml_get_pos: get pointer to position 'pos'
 */
    char_u *
ml_get_pos(pos)
    pos_T	*pos;
{
    return (ml_get_buf(curbuf, pos->lnum, FALSE) + pos->col);
}

/*
 * ml_get_curline: get pointer to cursor line.
 */
    char_u *
ml_get_curline()
{
    return ml_get_buf(curbuf, curwin->w_cursor.lnum, FALSE);
}

/*
 * ml_get_cursor: get pointer to cursor position
 */
    char_u *
ml_get_cursor()
{
    return (ml_get_buf(curbuf, curwin->w_cursor.lnum, FALSE) +
							curwin->w_cursor.col);
}

/*
 * get a pointer to a line in a specific buffer
 *
 * "will_change": if TRUE mark the buffer dirty (chars in the line will be
 * changed)
 */
    char_u  *
ml_get_buf(buf, lnum, will_change)
    buf_T	*buf;
    linenr_T	lnum;
    int		will_change;		/* line will be changed */
{
    bhdr_T	*hp;
    DATA_BL	*dp;
    char_u	*ptr;
    static int	recursive = 0;

    if (lnum > buf->b_ml.ml_line_count)	/* invalid line number */
    {
	if (recursive == 0)
	{
	    /* Avoid giving this message for a recursive call, may happen when
	     * the GUI redraws part of the text. */
	    ++recursive;
	    EMSGN(_("E315: ml_get: invalid lnum: %ld"), lnum);
	    --recursive;
	}
errorret:
	STRCPY(IObuff, "???");
	return IObuff;
    }
    if (lnum <= 0)			/* pretend line 0 is line 1 */
	lnum = 1;

    if (buf->b_ml.ml_mfp == NULL)	/* there are no lines */
	return (char_u *)"";

/*
 * See if it is the same line as requested last time.
 * Otherwise may need to flush last used line.
 * Don't use the last used line when 'swapfile' is reset, need to load all
 * blocks.
 */
    if (buf->b_ml.ml_line_lnum != lnum || mf_dont_release)
    {
	ml_flush_line(buf);

	/*
	 * Find the data block containing the line.
	 * This also fills the stack with the blocks from the root to the data
	 * block and releases any locked block.
	 */
	if ((hp = ml_find_line(buf, lnum, ML_FIND)) == NULL)
	{
	    if (recursive == 0)
	    {
		/* Avoid giving this message for a recursive call, may happen
		 * when the GUI redraws part of the text. */
		++recursive;
		EMSGN(_("E316: ml_get: cannot find line %ld"), lnum);
		--recursive;
	    }
	    goto errorret;
	}

	dp = (DATA_BL *)(hp->bh_data);

	ptr = (char_u *)dp + ((dp->db_index[lnum - buf->b_ml.ml_locked_low]) & DB_INDEX_MASK);
	buf->b_ml.ml_line_ptr = ptr;
	buf->b_ml.ml_line_lnum = lnum;
	buf->b_ml.ml_flags &= ~ML_LINE_DIRTY;
    }
    if (will_change)
	buf->b_ml.ml_flags |= (ML_LOCKED_DIRTY | ML_LOCKED_POS);

    return buf->b_ml.ml_line_ptr;
}

/*
 * Check if a line that was just obtained by a call to ml_get
 * is in allocated memory.
 */
    int
ml_line_alloced()
{
    return (curbuf->b_ml.ml_flags & ML_LINE_DIRTY);
}

/*
 * Append a line after lnum (may be 0 to insert a line in front of the file).
 * "line" does not need to be allocated, but can't be another line in a
 * buffer, unlocking may make it invalid.
 *
 *   newfile: TRUE when starting to edit a new file, meaning that pe_old_lnum
 *		will be set for recovery
 * Check: The caller of this function should probably also call
 * appended_lines().
 *
 * return FAIL for failure, OK otherwise
 */
    int
ml_append(lnum, line, len, newfile)
    linenr_T	lnum;		/* append after this line (can be 0) */
    char_u	*line;		/* text of the new line */
    colnr_T	len;		/* length of new line, including NUL, or 0 */
    int		newfile;	/* flag, see above */
{
    /* When starting up, we might still need to create the memfile */
    if (curbuf->b_ml.ml_mfp == NULL && open_buffer(FALSE, NULL) == FAIL)
	return FAIL;

    if (curbuf->b_ml.ml_line_lnum != 0)
	ml_flush_line(curbuf);
    return ml_append_int(curbuf, lnum, line, len, newfile, FALSE);
}

#if defined(FEAT_SPELL) || defined(PROTO)
/*
 * Like ml_append() but for an arbitrary buffer.  The buffer must already have
 * a memline.
 */
    int
ml_append_buf(buf, lnum, line, len, newfile)
    buf_T	*buf;
    linenr_T	lnum;		/* append after this line (can be 0) */
    char_u	*line;		/* text of the new line */
    colnr_T	len;		/* length of new line, including NUL, or 0 */
    int		newfile;	/* flag, see above */
{
    if (buf->b_ml.ml_mfp == NULL)
	return FAIL;

    if (buf->b_ml.ml_line_lnum != 0)
	ml_flush_line(buf);
    return ml_append_int(buf, lnum, line, len, newfile, FALSE);
}
#endif

    static int
ml_append_int(buf, lnum, line, len, newfile, mark)
    buf_T	*buf;
    linenr_T	lnum;		/* append after this line (can be 0) */
    char_u	*line;		/* text of the new line */
    colnr_T	len;		/* length of line, including NUL, or 0 */
    int		newfile;	/* flag, see above */
    int		mark;		/* mark the new line */
{
    int		i;
    int		line_count;	/* number of indexes in current block */
    int		offset;
    int		from, to;
    int		space_needed;	/* space needed for new line */
    int		page_size;
    int		page_count;
    int		db_idx;		/* index for lnum in data block */
    bhdr_T	*hp;
    memfile_T	*mfp;
    DATA_BL	*dp;
    PTR_BL	*pp;
    infoptr_T	*ip;

					/* lnum out of range */
    if (lnum > buf->b_ml.ml_line_count || buf->b_ml.ml_mfp == NULL)
	return FAIL;

    if (lowest_marked && lowest_marked > lnum)
	lowest_marked = lnum + 1;

    if (len == 0)
	len = (colnr_T)STRLEN(line) + 1;	/* space needed for the text */
    space_needed = len + INDEX_SIZE;	/* space needed for text + index */

    mfp = buf->b_ml.ml_mfp;
    page_size = mfp->mf_page_size;

/*
 * find the data block containing the previous line
 * This also fills the stack with the blocks from the root to the data block
 * This also releases any locked block.
 */
    if ((hp = ml_find_line(buf, lnum == 0 ? (linenr_T)1 : lnum,
							  ML_INSERT)) == NULL)
	return FAIL;

    buf->b_ml.ml_flags &= ~ML_EMPTY;

    if (lnum == 0)		/* got line one instead, correct db_idx */
	db_idx = -1;		/* careful, it is negative! */
    else
	db_idx = lnum - buf->b_ml.ml_locked_low;
		/* get line count before the insertion */
    line_count = buf->b_ml.ml_locked_high - buf->b_ml.ml_locked_low;

    dp = (DATA_BL *)(hp->bh_data);

/*
 * If
 * - there is not enough room in the current block
 * - appending to the last line in the block
 * - not appending to the last line in the file
 * insert in front of the next block.
 */
    if ((int)dp->db_free < space_needed && db_idx == line_count - 1
					    && lnum < buf->b_ml.ml_line_count)
    {
	/*
	 * Now that the line is not going to be inserted in the block that we
	 * expected, the line count has to be adjusted in the pointer blocks
	 * by using ml_locked_lineadd.
	 */
	--(buf->b_ml.ml_locked_lineadd);
	--(buf->b_ml.ml_locked_high);
	if ((hp = ml_find_line(buf, lnum + 1, ML_INSERT)) == NULL)
	    return FAIL;

	db_idx = -1;		    /* careful, it is negative! */
		    /* get line count before the insertion */
	line_count = buf->b_ml.ml_locked_high - buf->b_ml.ml_locked_low;
	CHECK(buf->b_ml.ml_locked_low != lnum + 1, "locked_low != lnum + 1");

	dp = (DATA_BL *)(hp->bh_data);
    }

    ++buf->b_ml.ml_line_count;

    if ((int)dp->db_free >= space_needed)	/* enough room in data block */
    {
/*
 * Insert new line in existing data block, or in data block allocated above.
 */
	dp->db_txt_start -= len;
	dp->db_free -= space_needed;
	++(dp->db_line_count);

	/*
	 * move the text of the lines that follow to the front
	 * adjust the indexes of the lines that follow
	 */
	if (line_count > db_idx + 1)	    /* if there are following lines */
	{
	    /*
	     * Offset is the start of the previous line.
	     * This will become the character just after the new line.
	     */
	    if (db_idx < 0)
		offset = dp->db_txt_end;
	    else
		offset = ((dp->db_index[db_idx]) & DB_INDEX_MASK);
	    mch_memmove((char *)dp + dp->db_txt_start,
					  (char *)dp + dp->db_txt_start + len,
				 (size_t)(offset - (dp->db_txt_start + len)));
	    for (i = line_count - 1; i > db_idx; --i)
		dp->db_index[i + 1] = dp->db_index[i] - len;
	    dp->db_index[db_idx + 1] = offset - len;
	}
	else				    /* add line at the end */
	    dp->db_index[db_idx + 1] = dp->db_txt_start;

	/*
	 * copy the text into the block
	 */
	mch_memmove((char *)dp + dp->db_index[db_idx + 1], line, (size_t)len);
	if (mark)
	    dp->db_index[db_idx + 1] |= DB_MARKED;

	/*
	 * Mark the block dirty.
	 */
	buf->b_ml.ml_flags |= ML_LOCKED_DIRTY;
	if (!newfile)
	    buf->b_ml.ml_flags |= ML_LOCKED_POS;
    }
    else	    /* not enough space in data block */
    {
/*
 * If there is not enough room we have to create a new data block and copy some
 * lines into it.
 * Then we have to insert an entry in the pointer block.
 * If this pointer block also is full, we go up another block, and so on, up
 * to the root if necessary.
 * The line counts in the pointer blocks have already been adjusted by
 * ml_find_line().
 */
	long	    line_count_left, line_count_right;
	int	    page_count_left, page_count_right;
	bhdr_T	    *hp_left;
	bhdr_T	    *hp_right;
	bhdr_T	    *hp_new;
	int	    lines_moved;
	int	    data_moved = 0;	    /* init to shut up gcc */
	int	    total_moved = 0;	    /* init to shut up gcc */
	DATA_BL	    *dp_right, *dp_left;
	int	    stack_idx;
	int	    in_left;
	int	    lineadd;
	blocknr_T   bnum_left, bnum_right;
	linenr_T    lnum_left, lnum_right;
	int	    pb_idx;
	PTR_BL	    *pp_new;

	/*
	 * We are going to allocate a new data block. Depending on the
	 * situation it will be put to the left or right of the existing
	 * block.  If possible we put the new line in the left block and move
	 * the lines after it to the right block. Otherwise the new line is
	 * also put in the right block. This method is more efficient when
	 * inserting a lot of lines at one place.
	 */
	if (db_idx < 0)		/* left block is new, right block is existing */
	{
	    lines_moved = 0;
	    in_left = TRUE;
	    /* space_needed does not change */
	}
	else			/* left block is existing, right block is new */
	{
	    lines_moved = line_count - db_idx - 1;
	    if (lines_moved == 0)
		in_left = FALSE;	/* put new line in right block */
					/* space_needed does not change */
	    else
	    {
		data_moved = ((dp->db_index[db_idx]) & DB_INDEX_MASK) -
							    dp->db_txt_start;
		total_moved = data_moved + lines_moved * INDEX_SIZE;
		if ((int)dp->db_free + total_moved >= space_needed)
		{
		    in_left = TRUE;	/* put new line in left block */
		    space_needed = total_moved;
		}
		else
		{
		    in_left = FALSE;	    /* put new line in right block */
		    space_needed += total_moved;
		}
	    }
	}

	page_count = ((space_needed + HEADER_SIZE) + page_size - 1) / page_size;
	if ((hp_new = ml_new_data(mfp, newfile, page_count)) == NULL)
	{
			/* correct line counts in pointer blocks */
	    --(buf->b_ml.ml_locked_lineadd);
	    --(buf->b_ml.ml_locked_high);
	    return FAIL;
	}
	if (db_idx < 0)		/* left block is new */
	{
	    hp_left = hp_new;
	    hp_right = hp;
	    line_count_left = 0;
	    line_count_right = line_count;
	}
	else			/* right block is new */
	{
	    hp_left = hp;
	    hp_right = hp_new;
	    line_count_left = line_count;
	    line_count_right = 0;
	}
	dp_right = (DATA_BL *)(hp_right->bh_data);
	dp_left = (DATA_BL *)(hp_left->bh_data);
	bnum_left = hp_left->bh_bnum;
	bnum_right = hp_right->bh_bnum;
	page_count_left = hp_left->bh_page_count;
	page_count_right = hp_right->bh_page_count;

	/*
	 * May move the new line into the right/new block.
	 */
	if (!in_left)
	{
	    dp_right->db_txt_start -= len;
	    dp_right->db_free -= len + INDEX_SIZE;
	    dp_right->db_index[0] = dp_right->db_txt_start;
	    if (mark)
		dp_right->db_index[0] |= DB_MARKED;

	    mch_memmove((char *)dp_right + dp_right->db_txt_start,
							   line, (size_t)len);
	    ++line_count_right;
	}
	/*
	 * may move lines from the left/old block to the right/new one.
	 */
	if (lines_moved)
	{
	    /*
	     */
	    dp_right->db_txt_start -= data_moved;
	    dp_right->db_free -= total_moved;
	    mch_memmove((char *)dp_right + dp_right->db_txt_start,
			(char *)dp_left + dp_left->db_txt_start,
			(size_t)data_moved);
	    offset = dp_right->db_txt_start - dp_left->db_txt_start;
	    dp_left->db_txt_start += data_moved;
	    dp_left->db_free += total_moved;

	    /*
	     * update indexes in the new block
	     */
	    for (to = line_count_right, from = db_idx + 1;
					 from < line_count_left; ++from, ++to)
		dp_right->db_index[to] = dp->db_index[from] + offset;
	    line_count_right += lines_moved;
	    line_count_left -= lines_moved;
	}

	/*
	 * May move the new line into the left (old or new) block.
	 */
	if (in_left)
	{
	    dp_left->db_txt_start -= len;
	    dp_left->db_free -= len + INDEX_SIZE;
	    dp_left->db_index[line_count_left] = dp_left->db_txt_start;
	    if (mark)
		dp_left->db_index[line_count_left] |= DB_MARKED;
	    mch_memmove((char *)dp_left + dp_left->db_txt_start,
							   line, (size_t)len);
	    ++line_count_left;
	}

	if (db_idx < 0)		/* left block is new */
	{
	    lnum_left = lnum + 1;
	    lnum_right = 0;
	}
	else			/* right block is new */
	{
	    lnum_left = 0;
	    if (in_left)
		lnum_right = lnum + 2;
	    else
		lnum_right = lnum + 1;
	}
	dp_left->db_line_count = line_count_left;
	dp_right->db_line_count = line_count_right;

	/*
	 * release the two data blocks
	 * The new one (hp_new) already has a correct blocknumber.
	 * The old one (hp, in ml_locked) gets a positive blocknumber if
	 * we changed it and we are not editing a new file.
	 */
	if (lines_moved || in_left)
	    buf->b_ml.ml_flags |= ML_LOCKED_DIRTY;
	if (!newfile && db_idx >= 0 && in_left)
	    buf->b_ml.ml_flags |= ML_LOCKED_POS;
	mf_put(mfp, hp_new, TRUE, FALSE);

	/*
	 * flush the old data block
	 * set ml_locked_lineadd to 0, because the updating of the
	 * pointer blocks is done below
	 */
	lineadd = buf->b_ml.ml_locked_lineadd;
	buf->b_ml.ml_locked_lineadd = 0;
	ml_find_line(buf, (linenr_T)0, ML_FLUSH);   /* flush data block */

	/*
	 * update pointer blocks for the new data block
	 */
	for (stack_idx = buf->b_ml.ml_stack_top - 1; stack_idx >= 0;
								  --stack_idx)
	{
	    ip = &(buf->b_ml.ml_stack[stack_idx]);
	    pb_idx = ip->ip_index;
	    if ((hp = mf_get(mfp, ip->ip_bnum, 1)) == NULL)
		return FAIL;
	    pp = (PTR_BL *)(hp->bh_data);   /* must be pointer block */
	    if (pp->pb_id != PTR_ID)
	    {
		EMSG(_("E317: pointer block id wrong 3"));
		mf_put(mfp, hp, FALSE, FALSE);
		return FAIL;
	    }
	    /*
	     * TODO: If the pointer block is full and we are adding at the end
	     * try to insert in front of the next block
	     */
	    /* block not full, add one entry */
	    if (pp->pb_count < pp->pb_count_max)
	    {
		if (pb_idx + 1 < (int)pp->pb_count)
		    mch_memmove(&pp->pb_pointer[pb_idx + 2],
				&pp->pb_pointer[pb_idx + 1],
			(size_t)(pp->pb_count - pb_idx - 1) * sizeof(PTR_EN));
		++pp->pb_count;
		pp->pb_pointer[pb_idx].pe_line_count = line_count_left;
		pp->pb_pointer[pb_idx].pe_bnum = bnum_left;
		pp->pb_pointer[pb_idx].pe_page_count = page_count_left;
		pp->pb_pointer[pb_idx + 1].pe_line_count = line_count_right;
		pp->pb_pointer[pb_idx + 1].pe_bnum = bnum_right;
		pp->pb_pointer[pb_idx + 1].pe_page_count = page_count_right;

		if (lnum_left != 0)
		    pp->pb_pointer[pb_idx].pe_old_lnum = lnum_left;
		if (lnum_right != 0)
		    pp->pb_pointer[pb_idx + 1].pe_old_lnum = lnum_right;

		mf_put(mfp, hp, TRUE, FALSE);
		buf->b_ml.ml_stack_top = stack_idx + 1;	    /* truncate stack */

		if (lineadd)
		{
		    --(buf->b_ml.ml_stack_top);
		    /* fix line count for rest of blocks in the stack */
		    ml_lineadd(buf, lineadd);
							/* fix stack itself */
		    buf->b_ml.ml_stack[buf->b_ml.ml_stack_top].ip_high +=
								      lineadd;
		    ++(buf->b_ml.ml_stack_top);
		}

		/*
		 * We are finished, break the loop here.
		 */
		break;
	    }
	    else			/* pointer block full */
	    {
		/*
		 * split the pointer block
		 * allocate a new pointer block
		 * move some of the pointer into the new block
		 * prepare for updating the parent block
		 */
		for (;;)	/* do this twice when splitting block 1 */
		{
		    hp_new = ml_new_ptr(mfp);
		    if (hp_new == NULL)	    /* TODO: try to fix tree */
			return FAIL;
		    pp_new = (PTR_BL *)(hp_new->bh_data);

		    if (hp->bh_bnum != 1)
			break;

		    /*
		     * if block 1 becomes full the tree is given an extra level
		     * The pointers from block 1 are moved into the new block.
		     * block 1 is updated to point to the new block
		     * then continue to split the new block
		     */
		    mch_memmove(pp_new, pp, (size_t)page_size);
		    pp->pb_count = 1;
		    pp->pb_pointer[0].pe_bnum = hp_new->bh_bnum;
		    pp->pb_pointer[0].pe_line_count = buf->b_ml.ml_line_count;
		    pp->pb_pointer[0].pe_old_lnum = 1;
		    pp->pb_pointer[0].pe_page_count = 1;
		    mf_put(mfp, hp, TRUE, FALSE);   /* release block 1 */
		    hp = hp_new;		/* new block is to be split */
		    pp = pp_new;
		    CHECK(stack_idx != 0, _("stack_idx should be 0"));
		    ip->ip_index = 0;
		    ++stack_idx;	/* do block 1 again later */
		}
		/*
		 * move the pointers after the current one to the new block
		 * If there are none, the new entry will be in the new block.
		 */
		total_moved = pp->pb_count - pb_idx - 1;
		if (total_moved)
		{
		    mch_memmove(&pp_new->pb_pointer[0],
				&pp->pb_pointer[pb_idx + 1],
				(size_t)(total_moved) * sizeof(PTR_EN));
		    pp_new->pb_count = total_moved;
		    pp->pb_count -= total_moved - 1;
		    pp->pb_pointer[pb_idx + 1].pe_bnum = bnum_right;
		    pp->pb_pointer[pb_idx + 1].pe_line_count = line_count_right;
		    pp->pb_pointer[pb_idx + 1].pe_page_count = page_count_right;
		    if (lnum_right)
			pp->pb_pointer[pb_idx + 1].pe_old_lnum = lnum_right;
		}
		else
		{
		    pp_new->pb_count = 1;
		    pp_new->pb_pointer[0].pe_bnum = bnum_right;
		    pp_new->pb_pointer[0].pe_line_count = line_count_right;
		    pp_new->pb_pointer[0].pe_page_count = page_count_right;
		    pp_new->pb_pointer[0].pe_old_lnum = lnum_right;
		}
		pp->pb_pointer[pb_idx].pe_bnum = bnum_left;
		pp->pb_pointer[pb_idx].pe_line_count = line_count_left;
		pp->pb_pointer[pb_idx].pe_page_count = page_count_left;
		if (lnum_left)
		    pp->pb_pointer[pb_idx].pe_old_lnum = lnum_left;
		lnum_left = 0;
		lnum_right = 0;

		/*
		 * recompute line counts
		 */
		line_count_right = 0;
		for (i = 0; i < (int)pp_new->pb_count; ++i)
		    line_count_right += pp_new->pb_pointer[i].pe_line_count;
		line_count_left = 0;
		for (i = 0; i < (int)pp->pb_count; ++i)
		    line_count_left += pp->pb_pointer[i].pe_line_count;

		bnum_left = hp->bh_bnum;
		bnum_right = hp_new->bh_bnum;
		page_count_left = 1;
		page_count_right = 1;
		mf_put(mfp, hp, TRUE, FALSE);
		mf_put(mfp, hp_new, TRUE, FALSE);
	    }
	}

	/*
	 * Safety check: fallen out of for loop?
	 */
	if (stack_idx < 0)
	{
	    EMSG(_("E318: Updated too many blocks?"));
	    buf->b_ml.ml_stack_top = 0;	/* invalidate stack */
	}
    }

#ifdef FEAT_BYTEOFF
    /* The line was inserted below 'lnum' */
    ml_updatechunk(buf, lnum + 1, (long)len, ML_CHNK_ADDLINE);
#endif
#ifdef FEAT_NETBEANS_INTG
    if (usingNetbeans)
    {
	if (STRLEN(line) > 0)
	    netbeans_inserted(buf, lnum+1, (colnr_T)0, line, (int)STRLEN(line));
	netbeans_inserted(buf, lnum+1, (colnr_T)STRLEN(line),
							   (char_u *)"\n", 1);
    }
#endif
    return OK;
}

/*
 * Replace line lnum, with buffering, in current buffer.
 *
 * If "copy" is TRUE, make a copy of the line, otherwise the line has been
 * copied to allocated memory already.
 *
 * Check: The caller of this function should probably also call
 * changed_lines(), unless update_screen(NOT_VALID) is used.
 *
 * return FAIL for failure, OK otherwise
 */
    int
ml_replace(lnum, line, copy)
    linenr_T	lnum;
    char_u	*line;
    int		copy;
{
    if (line == NULL)		/* just checking... */
	return FAIL;

    /* When starting up, we might still need to create the memfile */
    if (curbuf->b_ml.ml_mfp == NULL && open_buffer(FALSE, NULL) == FAIL)
	return FAIL;

    if (copy && (line = vim_strsave(line)) == NULL) /* allocate memory */
	return FAIL;
#ifdef FEAT_NETBEANS_INTG
    if (usingNetbeans)
    {
	netbeans_removed(curbuf, lnum, 0, (long)STRLEN(ml_get(lnum)));
	netbeans_inserted(curbuf, lnum, 0, line, (int)STRLEN(line));
    }
#endif
    if (curbuf->b_ml.ml_line_lnum != lnum)	    /* other line buffered */
	ml_flush_line(curbuf);			    /* flush it */
    else if (curbuf->b_ml.ml_flags & ML_LINE_DIRTY) /* same line allocated */
	vim_free(curbuf->b_ml.ml_line_ptr);	    /* free it */
    curbuf->b_ml.ml_line_ptr = line;
    curbuf->b_ml.ml_line_lnum = lnum;
    curbuf->b_ml.ml_flags = (curbuf->b_ml.ml_flags | ML_LINE_DIRTY) & ~ML_EMPTY;

    return OK;
}

/*
 * Delete line 'lnum' in the current buffer.
 *
 * Check: The caller of this function should probably also call
 * deleted_lines() after this.
 *
 * return FAIL for failure, OK otherwise
 */
    int
ml_delete(lnum, message)
    linenr_T	lnum;
    int		message;
{
    ml_flush_line(curbuf);
    return ml_delete_int(curbuf, lnum, message);
}

    static int
ml_delete_int(buf, lnum, message)
    buf_T	*buf;
    linenr_T	lnum;
    int		message;
{
    bhdr_T	*hp;
    memfile_T	*mfp;
    DATA_BL	*dp;
    PTR_BL	*pp;
    infoptr_T	*ip;
    int		count;	    /* number of entries in block */
    int		idx;
    int		stack_idx;
    int		text_start;
    int		line_start;
    long	line_size;
    int		i;

    if (lnum < 1 || lnum > buf->b_ml.ml_line_count)
	return FAIL;

    if (lowest_marked && lowest_marked > lnum)
	lowest_marked--;

/*
 * If the file becomes empty the last line is replaced by an empty line.
 */
    if (buf->b_ml.ml_line_count == 1)	    /* file becomes empty */
    {
	if (message
#ifdef FEAT_NETBEANS_INTG
		&& !netbeansSuppressNoLines
#endif
	   )
	    set_keep_msg((char_u *)_(no_lines_msg), 0);

	/* FEAT_BYTEOFF already handled in there, dont worry 'bout it below */
	i = ml_replace((linenr_T)1, (char_u *)"", TRUE);
	buf->b_ml.ml_flags |= ML_EMPTY;

	return i;
    }

/*
 * find the data block containing the line
 * This also fills the stack with the blocks from the root to the data block
 * This also releases any locked block.
 */
    mfp = buf->b_ml.ml_mfp;
    if (mfp == NULL)
	return FAIL;

    if ((hp = ml_find_line(buf, lnum, ML_DELETE)) == NULL)
	return FAIL;

    dp = (DATA_BL *)(hp->bh_data);
    /* compute line count before the delete */
    count = (long)(buf->b_ml.ml_locked_high)
					- (long)(buf->b_ml.ml_locked_low) + 2;
    idx = lnum - buf->b_ml.ml_locked_low;

    --buf->b_ml.ml_line_count;

    line_start = ((dp->db_index[idx]) & DB_INDEX_MASK);
    if (idx == 0)		/* first line in block, text at the end */
	line_size = dp->db_txt_end - line_start;
    else
	line_size = ((dp->db_index[idx - 1]) & DB_INDEX_MASK) - line_start;

#ifdef FEAT_NETBEANS_INTG
    if (usingNetbeans)
	netbeans_removed(buf, lnum, 0, (long)line_size);
#endif

/*
 * special case: If there is only one line in the data block it becomes empty.
 * Then we have to remove the entry, pointing to this data block, from the
 * pointer block. If this pointer block also becomes empty, we go up another
 * block, and so on, up to the root if necessary.
 * The line counts in the pointer blocks have already been adjusted by
 * ml_find_line().
 */
    if (count == 1)
    {
	mf_free(mfp, hp);	/* free the data block */
	buf->b_ml.ml_locked = NULL;

	for (stack_idx = buf->b_ml.ml_stack_top - 1; stack_idx >= 0; --stack_idx)
	{
	    buf->b_ml.ml_stack_top = 0;	    /* stack is invalid when failing */
	    ip = &(buf->b_ml.ml_stack[stack_idx]);
	    idx = ip->ip_index;
	    if ((hp = mf_get(mfp, ip->ip_bnum, 1)) == NULL)
		return FAIL;
	    pp = (PTR_BL *)(hp->bh_data);   /* must be pointer block */
	    if (pp->pb_id != PTR_ID)
	    {
		EMSG(_("E317: pointer block id wrong 4"));
		mf_put(mfp, hp, FALSE, FALSE);
		return FAIL;
	    }
	    count = --(pp->pb_count);
	    if (count == 0)	    /* the pointer block becomes empty! */
		mf_free(mfp, hp);
	    else
	    {
		if (count != idx)	/* move entries after the deleted one */
		    mch_memmove(&pp->pb_pointer[idx], &pp->pb_pointer[idx + 1],
				      (size_t)(count - idx) * sizeof(PTR_EN));
		mf_put(mfp, hp, TRUE, FALSE);

		buf->b_ml.ml_stack_top = stack_idx;	/* truncate stack */
		/* fix line count for rest of blocks in the stack */
		if (buf->b_ml.ml_locked_lineadd != 0)
		{
		    ml_lineadd(buf, buf->b_ml.ml_locked_lineadd);
		    buf->b_ml.ml_stack[buf->b_ml.ml_stack_top].ip_high +=
						  buf->b_ml.ml_locked_lineadd;
		}
		++(buf->b_ml.ml_stack_top);

		break;
	    }
	}
	CHECK(stack_idx < 0, _("deleted block 1?"));
    }
    else
    {
	/*
	 * delete the text by moving the next lines forwards
	 */
	text_start = dp->db_txt_start;
	mch_memmove((char *)dp + text_start + line_size,
		  (char *)dp + text_start, (size_t)(line_start - text_start));

	/*
	 * delete the index by moving the next indexes backwards
	 * Adjust the indexes for the text movement.
	 */
	for (i = idx; i < count - 1; ++i)
	    dp->db_index[i] = dp->db_index[i + 1] + line_size;

	dp->db_free += line_size + INDEX_SIZE;
	dp->db_txt_start += line_size;
	--(dp->db_line_count);

	/*
	 * mark the block dirty and make sure it is in the file (for recovery)
	 */
	buf->b_ml.ml_flags |= (ML_LOCKED_DIRTY | ML_LOCKED_POS);
    }

#ifdef FEAT_BYTEOFF
    ml_updatechunk(buf, lnum, line_size, ML_CHNK_DELLINE);
#endif
    return OK;
}

/*
 * set the B_MARKED flag for line 'lnum'
 */
    void
ml_setmarked(lnum)
    linenr_T lnum;
{
    bhdr_T    *hp;
    DATA_BL *dp;
				    /* invalid line number */
    if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count
					       || curbuf->b_ml.ml_mfp == NULL)
	return;			    /* give error message? */

    if (lowest_marked == 0 || lowest_marked > lnum)
	lowest_marked = lnum;

    /*
     * find the data block containing the line
     * This also fills the stack with the blocks from the root to the data block
     * This also releases any locked block.
     */
    if ((hp = ml_find_line(curbuf, lnum, ML_FIND)) == NULL)
	return;		    /* give error message? */

    dp = (DATA_BL *)(hp->bh_data);
    dp->db_index[lnum - curbuf->b_ml.ml_locked_low] |= DB_MARKED;
    curbuf->b_ml.ml_flags |= ML_LOCKED_DIRTY;
}

/*
 * find the first line with its B_MARKED flag set
 */
    linenr_T
ml_firstmarked()
{
    bhdr_T	*hp;
    DATA_BL	*dp;
    linenr_T	lnum;
    int		i;

    if (curbuf->b_ml.ml_mfp == NULL)
	return (linenr_T) 0;

    /*
     * The search starts with lowest_marked line. This is the last line where
     * a mark was found, adjusted by inserting/deleting lines.
     */
    for (lnum = lowest_marked; lnum <= curbuf->b_ml.ml_line_count; )
    {
	/*
	 * Find the data block containing the line.
	 * This also fills the stack with the blocks from the root to the data
	 * block This also releases any locked block.
	 */
	if ((hp = ml_find_line(curbuf, lnum, ML_FIND)) == NULL)
	    return (linenr_T)0;		    /* give error message? */

	dp = (DATA_BL *)(hp->bh_data);

	for (i = lnum - curbuf->b_ml.ml_locked_low;
			    lnum <= curbuf->b_ml.ml_locked_high; ++i, ++lnum)
	    if ((dp->db_index[i]) & DB_MARKED)
	    {
		(dp->db_index[i]) &= DB_INDEX_MASK;
		curbuf->b_ml.ml_flags |= ML_LOCKED_DIRTY;
		lowest_marked = lnum + 1;
		return lnum;
	    }
    }

    return (linenr_T) 0;
}

#if 0  /* not used */
/*
 * return TRUE if line 'lnum' has a mark
 */
    int
ml_has_mark(lnum)
    linenr_T	lnum;
{
    bhdr_T	*hp;
    DATA_BL	*dp;

    if (curbuf->b_ml.ml_mfp == NULL
			|| (hp = ml_find_line(curbuf, lnum, ML_FIND)) == NULL)
	return FALSE;

    dp = (DATA_BL *)(hp->bh_data);
    return (int)((dp->db_index[lnum - curbuf->b_ml.ml_locked_low]) & DB_MARKED);
}
#endif

/*
 * clear all DB_MARKED flags
 */
    void
ml_clearmarked()
{
    bhdr_T	*hp;
    DATA_BL	*dp;
    linenr_T	lnum;
    int		i;

    if (curbuf->b_ml.ml_mfp == NULL)	    /* nothing to do */
	return;

    /*
     * The search starts with line lowest_marked.
     */
    for (lnum = lowest_marked; lnum <= curbuf->b_ml.ml_line_count; )
    {
	/*
	 * Find the data block containing the line.
	 * This also fills the stack with the blocks from the root to the data
	 * block and releases any locked block.
	 */
	if ((hp = ml_find_line(curbuf, lnum, ML_FIND)) == NULL)
	    return;		/* give error message? */

	dp = (DATA_BL *)(hp->bh_data);

	for (i = lnum - curbuf->b_ml.ml_locked_low;
			    lnum <= curbuf->b_ml.ml_locked_high; ++i, ++lnum)
	    if ((dp->db_index[i]) & DB_MARKED)
	    {
		(dp->db_index[i]) &= DB_INDEX_MASK;
		curbuf->b_ml.ml_flags |= ML_LOCKED_DIRTY;
	    }
    }

    lowest_marked = 0;
    return;
}

/*
 * flush ml_line if necessary
 */
    static void
ml_flush_line(buf)
    buf_T	*buf;
{
    bhdr_T	*hp;
    DATA_BL	*dp;
    linenr_T	lnum;
    char_u	*new_line;
    char_u	*old_line;
    colnr_T	new_len;
    int		old_len;
    int		extra;
    int		idx;
    int		start;
    int		count;
    int		i;

    if (buf->b_ml.ml_line_lnum == 0 || buf->b_ml.ml_mfp == NULL)
	return;		/* nothing to do */

    if (buf->b_ml.ml_flags & ML_LINE_DIRTY)
    {
	lnum = buf->b_ml.ml_line_lnum;
	new_line = buf->b_ml.ml_line_ptr;

	hp = ml_find_line(buf, lnum, ML_FIND);
	if (hp == NULL)
	    EMSGN(_("E320: Cannot find line %ld"), lnum);
	else
	{
	    dp = (DATA_BL *)(hp->bh_data);
	    idx = lnum - buf->b_ml.ml_locked_low;
	    start = ((dp->db_index[idx]) & DB_INDEX_MASK);
	    old_line = (char_u *)dp + start;
	    if (idx == 0)	/* line is last in block */
		old_len = dp->db_txt_end - start;
	    else		/* text of previous line follows */
		old_len = (dp->db_index[idx - 1] & DB_INDEX_MASK) - start;
	    new_len = (colnr_T)STRLEN(new_line) + 1;
	    extra = new_len - old_len;	    /* negative if lines gets smaller */

	    /*
	     * if new line fits in data block, replace directly
	     */
	    if ((int)dp->db_free >= extra)
	    {
		/* if the length changes and there are following lines */
		count = buf->b_ml.ml_locked_high - buf->b_ml.ml_locked_low + 1;
		if (extra != 0 && idx < count - 1)
		{
		    /* move text of following lines */
		    mch_memmove((char *)dp + dp->db_txt_start - extra,
				(char *)dp + dp->db_txt_start,
				(size_t)(start - dp->db_txt_start));

		    /* adjust pointers of this and following lines */
		    for (i = idx + 1; i < count; ++i)
			dp->db_index[i] -= extra;
		}
		dp->db_index[idx] -= extra;

		/* adjust free space */
		dp->db_free -= extra;
		dp->db_txt_start -= extra;

		/* copy new line into the data block */
		mch_memmove(old_line - extra, new_line, (size_t)new_len);
		buf->b_ml.ml_flags |= (ML_LOCKED_DIRTY | ML_LOCKED_POS);
#ifdef FEAT_BYTEOFF
		/* The else case is already covered by the insert and delete */
		ml_updatechunk(buf, lnum, (long)extra, ML_CHNK_UPDLINE);
#endif
	    }
	    else
	    {
		/*
		 * Cannot do it in one data block: Delete and append.
		 * Append first, because ml_delete_int() cannot delete the
		 * last line in a buffer, which causes trouble for a buffer
		 * that has only one line.
		 * Don't forget to copy the mark!
		 */
		/* How about handling errors??? */
		(void)ml_append_int(buf, lnum, new_line, new_len, FALSE,
					     (dp->db_index[idx] & DB_MARKED));
		(void)ml_delete_int(buf, lnum, FALSE);
	    }
	}
	vim_free(new_line);
    }

    buf->b_ml.ml_line_lnum = 0;
}

/*
 * create a new, empty, data block
 */
    static bhdr_T *
ml_new_data(mfp, negative, page_count)
    memfile_T	*mfp;
    int		negative;
    int		page_count;
{
    bhdr_T	*hp;
    DATA_BL	*dp;

    if ((hp = mf_new(mfp, negative, page_count)) == NULL)
	return NULL;

    dp = (DATA_BL *)(hp->bh_data);
    dp->db_id = DATA_ID;
    dp->db_txt_start = dp->db_txt_end = page_count * mfp->mf_page_size;
    dp->db_free = dp->db_txt_start - HEADER_SIZE;
    dp->db_line_count = 0;

    return hp;
}

/*
 * create a new, empty, pointer block
 */
    static bhdr_T *
ml_new_ptr(mfp)
    memfile_T	*mfp;
{
    bhdr_T	*hp;
    PTR_BL	*pp;

    if ((hp = mf_new(mfp, FALSE, 1)) == NULL)
	return NULL;

    pp = (PTR_BL *)(hp->bh_data);
    pp->pb_id = PTR_ID;
    pp->pb_count = 0;
    pp->pb_count_max = (short_u)((mfp->mf_page_size - sizeof(PTR_BL)) / sizeof(PTR_EN) + 1);

    return hp;
}

/*
 * lookup line 'lnum' in a memline
 *
 *   action: if ML_DELETE or ML_INSERT the line count is updated while searching
 *	     if ML_FLUSH only flush a locked block
 *	     if ML_FIND just find the line
 *
 * If the block was found it is locked and put in ml_locked.
 * The stack is updated to lead to the locked block. The ip_high field in
 * the stack is updated to reflect the last line in the block AFTER the
 * insert or delete, also if the pointer block has not been updated yet. But
 * if ml_locked != NULL ml_locked_lineadd must be added to ip_high.
 *
 * return: NULL for failure, pointer to block header otherwise
 */
    static bhdr_T *
ml_find_line(buf, lnum, action)
    buf_T	*buf;
    linenr_T	lnum;
    int		action;
{
    DATA_BL	*dp;
    PTR_BL	*pp;
    infoptr_T	*ip;
    bhdr_T	*hp;
    memfile_T	*mfp;
    linenr_T	t;
    blocknr_T	bnum, bnum2;
    int		dirty;
    linenr_T	low, high;
    int		top;
    int		page_count;
    int		idx;

    mfp = buf->b_ml.ml_mfp;

    /*
     * If there is a locked block check if the wanted line is in it.
     * If not, flush and release the locked block.
     * Don't do this for ML_INSERT_SAME, because the stack need to be updated.
     * Don't do this for ML_FLUSH, because we want to flush the locked block.
     * Don't do this when 'swapfile' is reset, we want to load all the blocks.
     */
    if (buf->b_ml.ml_locked)
    {
	if (ML_SIMPLE(action)
		&& buf->b_ml.ml_locked_low <= lnum
		&& buf->b_ml.ml_locked_high >= lnum
		&& !mf_dont_release)
	{
	    /* remember to update pointer blocks and stack later */
	    if (action == ML_INSERT)
	    {
		++(buf->b_ml.ml_locked_lineadd);
		++(buf->b_ml.ml_locked_high);
	    }
	    else if (action == ML_DELETE)
	    {
		--(buf->b_ml.ml_locked_lineadd);
		--(buf->b_ml.ml_locked_high);
	    }
	    return (buf->b_ml.ml_locked);
	}

	mf_put(mfp, buf->b_ml.ml_locked, buf->b_ml.ml_flags & ML_LOCKED_DIRTY,
					    buf->b_ml.ml_flags & ML_LOCKED_POS);
	buf->b_ml.ml_locked = NULL;

	/*
	 * If lines have been added or deleted in the locked block, need to
	 * update the line count in pointer blocks.
	 */
	if (buf->b_ml.ml_locked_lineadd != 0)
	    ml_lineadd(buf, buf->b_ml.ml_locked_lineadd);
    }

    if (action == ML_FLUSH)	    /* nothing else to do */
	return NULL;

    bnum = 1;			    /* start at the root of the tree */
    page_count = 1;
    low = 1;
    high = buf->b_ml.ml_line_count;

    if (action == ML_FIND)	/* first try stack entries */
    {
	for (top = buf->b_ml.ml_stack_top - 1; top >= 0; --top)
	{
	    ip = &(buf->b_ml.ml_stack[top]);
	    if (ip->ip_low <= lnum && ip->ip_high >= lnum)
	    {
		bnum = ip->ip_bnum;
		low = ip->ip_low;
		high = ip->ip_high;
		buf->b_ml.ml_stack_top = top;	/* truncate stack at prev entry */
		break;
	    }
	}
	if (top < 0)
	    buf->b_ml.ml_stack_top = 0;		/* not found, start at the root */
    }
    else	/* ML_DELETE or ML_INSERT */
	buf->b_ml.ml_stack_top = 0;	/* start at the root */

/*
 * search downwards in the tree until a data block is found
 */
    for (;;)
    {
	if ((hp = mf_get(mfp, bnum, page_count)) == NULL)
	    goto error_noblock;

	/*
	 * update high for insert/delete
	 */
	if (action == ML_INSERT)
	    ++high;
	else if (action == ML_DELETE)
	    --high;

	dp = (DATA_BL *)(hp->bh_data);
	if (dp->db_id == DATA_ID)	/* data block */
	{
	    buf->b_ml.ml_locked = hp;
	    buf->b_ml.ml_locked_low = low;
	    buf->b_ml.ml_locked_high = high;
	    buf->b_ml.ml_locked_lineadd = 0;
	    buf->b_ml.ml_flags &= ~(ML_LOCKED_DIRTY | ML_LOCKED_POS);
	    return hp;
	}

	pp = (PTR_BL *)(dp);		/* must be pointer block */
	if (pp->pb_id != PTR_ID)
	{
	    EMSG(_("E317: pointer block id wrong"));
	    goto error_block;
	}

	if ((top = ml_add_stack(buf)) < 0)	/* add new entry to stack */
	    goto error_block;
	ip = &(buf->b_ml.ml_stack[top]);
	ip->ip_bnum = bnum;
	ip->ip_low = low;
	ip->ip_high = high;
	ip->ip_index = -1;		/* index not known yet */

	dirty = FALSE;
	for (idx = 0; idx < (int)pp->pb_count; ++idx)
	{
	    t = pp->pb_pointer[idx].pe_line_count;
	    CHECK(t == 0, _("pe_line_count is zero"));
	    if ((low += t) > lnum)
	    {
		ip->ip_index = idx;
		bnum = pp->pb_pointer[idx].pe_bnum;
		page_count = pp->pb_pointer[idx].pe_page_count;
		high = low - 1;
		low -= t;

		/*
		 * a negative block number may have been changed
		 */
		if (bnum < 0)
		{
		    bnum2 = mf_trans_del(mfp, bnum);
		    if (bnum != bnum2)
		    {
			bnum = bnum2;
			pp->pb_pointer[idx].pe_bnum = bnum;
			dirty = TRUE;
		    }
		}

		break;
	    }
	}
	if (idx >= (int)pp->pb_count)	    /* past the end: something wrong! */
	{
	    if (lnum > buf->b_ml.ml_line_count)
		EMSGN(_("E322: line number out of range: %ld past the end"),
					      lnum - buf->b_ml.ml_line_count);

	    else
		EMSGN(_("E323: line count wrong in block %ld"), bnum);
	    goto error_block;
	}
	if (action == ML_DELETE)
	{
	    pp->pb_pointer[idx].pe_line_count--;
	    dirty = TRUE;
	}
	else if (action == ML_INSERT)
	{
	    pp->pb_pointer[idx].pe_line_count++;
	    dirty = TRUE;
	}
	mf_put(mfp, hp, dirty, FALSE);
    }

error_block:
    mf_put(mfp, hp, FALSE, FALSE);
error_noblock:
/*
 * If action is ML_DELETE or ML_INSERT we have to correct the tree for
 * the incremented/decremented line counts, because there won't be a line
 * inserted/deleted after all.
 */
    if (action == ML_DELETE)
	ml_lineadd(buf, 1);
    else if (action == ML_INSERT)
	ml_lineadd(buf, -1);
    buf->b_ml.ml_stack_top = 0;
    return NULL;
}

/*
 * add an entry to the info pointer stack
 *
 * return -1 for failure, number of the new entry otherwise
 */
    static int
ml_add_stack(buf)
    buf_T	*buf;
{
    int		top;
    infoptr_T	*newstack;

    top = buf->b_ml.ml_stack_top;

	/* may have to increase the stack size */
    if (top == buf->b_ml.ml_stack_size)
    {
	CHECK(top > 0, _("Stack size increases"));	/* more than 5 levels??? */

	newstack = (infoptr_T *)alloc((unsigned)sizeof(infoptr_T) *
					(buf->b_ml.ml_stack_size + STACK_INCR));
	if (newstack == NULL)
	    return -1;
	mch_memmove(newstack, buf->b_ml.ml_stack, (size_t)top * sizeof(infoptr_T));
	vim_free(buf->b_ml.ml_stack);
	buf->b_ml.ml_stack = newstack;
	buf->b_ml.ml_stack_size += STACK_INCR;
    }

    buf->b_ml.ml_stack_top++;
    return top;
}

/*
 * Update the pointer blocks on the stack for inserted/deleted lines.
 * The stack itself is also updated.
 *
 * When a insert/delete line action fails, the line is not inserted/deleted,
 * but the pointer blocks have already been updated. That is fixed here by
 * walking through the stack.
 *
 * Count is the number of lines added, negative if lines have been deleted.
 */
    static void
ml_lineadd(buf, count)
    buf_T	*buf;
    int		count;
{
    int		idx;
    infoptr_T	*ip;
    PTR_BL	*pp;
    memfile_T	*mfp = buf->b_ml.ml_mfp;
    bhdr_T	*hp;

    for (idx = buf->b_ml.ml_stack_top - 1; idx >= 0; --idx)
    {
	ip = &(buf->b_ml.ml_stack[idx]);
	if ((hp = mf_get(mfp, ip->ip_bnum, 1)) == NULL)
	    break;
	pp = (PTR_BL *)(hp->bh_data);	/* must be pointer block */
	if (pp->pb_id != PTR_ID)
	{
	    mf_put(mfp, hp, FALSE, FALSE);
	    EMSG(_("E317: pointer block id wrong 2"));
	    break;
	}
	pp->pb_pointer[ip->ip_index].pe_line_count += count;
	ip->ip_high += count;
	mf_put(mfp, hp, TRUE, FALSE);
    }
}

#ifdef HAVE_READLINK
static int resolve_symlink __ARGS((char_u *fname, char_u *buf));

/*
 * Resolve a symlink in the last component of a file name.
 * Note that f_resolve() does it for every part of the path, we don't do that
 * here.
 * If it worked returns OK and the resolved link in "buf[MAXPATHL]".
 * Otherwise returns FAIL.
 */
    static int
resolve_symlink(fname, buf)
    char_u	*fname;
    char_u	*buf;
{
    char_u	tmp[MAXPATHL];
    int		ret;
    int		depth = 0;

    if (fname == NULL)
	return FAIL;

    /* Put the result so far in tmp[], starting with the original name. */
    vim_strncpy(tmp, fname, MAXPATHL - 1);

    for (;;)
    {
	/* Limit symlink depth to 100, catch recursive loops. */
	if (++depth == 100)
	{
	    EMSG2(_("E773: Symlink loop for \"%s\""), fname);
	    return FAIL;
	}

	ret = readlink((char *)tmp, (char *)buf, MAXPATHL - 1);
	if (ret <= 0)
	{
	    if (errno == EINVAL || errno == ENOENT)
	    {
		/* Found non-symlink or not existing file, stop here.
		 * When at the first level use the unmodifed name, skip the
		 * call to vim_FullName(). */
		if (depth == 1)
		    return FAIL;

		/* Use the resolved name in tmp[]. */
		break;
	    }

	    /* There must be some error reading links, use original name. */
	    return FAIL;
	}
	buf[ret] = NUL;

	/*
	 * Check whether the symlink is relative or absolute.
	 * If it's relative, build a new path based on the directory
	 * portion of the filename (if any) and the path the symlink
	 * points to.
	 */
	if (mch_isFullName(buf))
	    STRCPY(tmp, buf);
	else
	{
	    char_u *tail;

	    tail = gettail(tmp);
	    if (STRLEN(tail) + STRLEN(buf) >= MAXPATHL)
		return FAIL;
	    STRCPY(tail, buf);
	}
    }

    /*
     * Try to resolve the full name of the file so that the swapfile name will
     * be consistent even when opening a relative symlink from different
     * working directories.
     */
    return vim_FullName(tmp, buf, MAXPATHL, TRUE);
}
#endif

/*
 * Make swap file name out of the file name and a directory name.
 * Returns pointer to allocated memory or NULL.
 */
/*ARGSUSED*/
    char_u *
makeswapname(fname, ffname, buf, dir_name)
    char_u	*fname;
    char_u	*ffname;
    buf_T	*buf;
    char_u	*dir_name;
{
    char_u	*r, *s;
#ifdef HAVE_READLINK
    char_u	fname_buf[MAXPATHL];
    char_u	*fname_res;
#endif

#if defined(UNIX) || defined(WIN3264)  /* Need _very_ long file names */
    s = dir_name + STRLEN(dir_name);
    if (after_pathsep(dir_name, s) && s[-1] == s[-2])
    {			       /* Ends with '//', Use Full path */
	r = NULL;
	if ((s = make_percent_swname(dir_name, fname)) != NULL)
	{
	    r = modname(s, (char_u *)".swp", FALSE);
	    vim_free(s);
	}
	return r;
    }
#endif

#ifdef HAVE_READLINK
    /* Expand symlink in the file name, so that we put the swap file with the
     * actual file instead of with the symlink. */
    if (resolve_symlink(fname, fname_buf) == OK)
	fname_res = fname_buf;
    else
	fname_res = fname;
#endif

    r = buf_modname(
#ifdef SHORT_FNAME
	    TRUE,
#else
	    (buf->b_p_sn || buf->b_shortname),
#endif
#ifdef RISCOS
	    /* Avoid problems if fname has special chars, eg <Wimp$Scrap> */
	    ffname,
#else
# ifdef HAVE_READLINK
	    fname_res,
# else
	    fname,
# endif
#endif
	    (char_u *)
#if defined(VMS) || defined(RISCOS)
	    "_swp",
#else
	    ".swp",
#endif
#ifdef SHORT_FNAME		/* always 8.3 file name */
	    FALSE
#else
	    /* Prepend a '.' to the swap file name for the current directory. */
	    dir_name[0] == '.' && dir_name[1] == NUL
#endif
	       );
    if (r == NULL)	    /* out of memory */
	return NULL;

    s = get_file_in_dir(r, dir_name);
    vim_free(r);
    return s;
}

/*
 * Get file name to use for swap file or backup file.
 * Use the name of the edited file "fname" and an entry in the 'dir' or 'bdir'
 * option "dname".
 * - If "dname" is ".", return "fname" (swap file in dir of file).
 * - If "dname" starts with "./", insert "dname" in "fname" (swap file
 *   relative to dir of file).
 * - Otherwise, prepend "dname" to the tail of "fname" (swap file in specific
 *   dir).
 *
 * The return value is an allocated string and can be NULL.
 */
    char_u *
get_file_in_dir(fname, dname)
    char_u  *fname;
    char_u  *dname;	/* don't use "dirname", it is a global for Alpha */
{
    char_u	*t;
    char_u	*tail;
    char_u	*retval;
    int		save_char;

    tail = gettail(fname);

    if (dname[0] == '.' && dname[1] == NUL)
	retval = vim_strsave(fname);
    else if (dname[0] == '.' && vim_ispathsep(dname[1]))
    {
	if (tail == fname)	    /* no path before file name */
	    retval = concat_fnames(dname + 2, tail, TRUE);
	else
	{
	    save_char = *tail;
	    *tail = NUL;
	    t = concat_fnames(fname, dname + 2, TRUE);
	    *tail = save_char;
	    if (t == NULL)	    /* out of memory */
		retval = NULL;
	    else
	    {
		retval = concat_fnames(t, tail, TRUE);
		vim_free(t);
	    }
	}
    }
    else
	retval = concat_fnames(dname, tail, TRUE);

    return retval;
}

static void attention_message __ARGS((buf_T *buf, char_u *fname));

/*
 * Print the ATTENTION message: info about an existing swap file.
 */
    static void
attention_message(buf, fname)
    buf_T   *buf;	/* buffer being edited */
    char_u  *fname;	/* swap file name */
{
    struct stat st;
    time_t	x, sx;
    char	*p;

    ++no_wait_return;
    (void)EMSG(_("E325: ATTENTION"));
    MSG_PUTS(_("\nFound a swap file by the name \""));
    msg_home_replace(fname);
    MSG_PUTS("\"\n");
    sx = swapfile_info(fname);
    MSG_PUTS(_("While opening file \""));
    msg_outtrans(buf->b_fname);
    MSG_PUTS("\"\n");
    if (mch_stat((char *)buf->b_fname, &st) != -1)
    {
	MSG_PUTS(_("             dated: "));
	x = st.st_mtime;    /* Manx C can't do &st.st_mtime */
	p = ctime(&x);			    /* includes '\n' */
	if (p == NULL)
	    MSG_PUTS("(invalid)\n");
	else
	    MSG_PUTS(p);
	if (sx != 0 && x > sx)
	    MSG_PUTS(_("      NEWER than swap file!\n"));
    }
    /* Some of these messages are long to allow translation to
     * other languages. */
    MSG_PUTS(_("\n(1) Another program may be editing the same file.\n    If this is the case, be careful not to end up with two\n    different instances of the same file when making changes.\n"));
    MSG_PUTS(_("    Quit, or continue with caution.\n"));
    MSG_PUTS(_("\n(2) An edit session for this file crashed.\n"));
    MSG_PUTS(_("    If this is the case, use \":recover\" or \"vim -r "));
    msg_outtrans(buf->b_fname);
    MSG_PUTS(_("\"\n    to recover the changes (see \":help recovery\").\n"));
    MSG_PUTS(_("    If you did this already, delete the swap file \""));
    msg_outtrans(fname);
    MSG_PUTS(_("\"\n    to avoid this message.\n"));
    cmdline_row = msg_row;
    --no_wait_return;
}

#ifdef FEAT_AUTOCMD
static int do_swapexists __ARGS((buf_T *buf, char_u *fname));

/*
 * Trigger the SwapExists autocommands.
 * Returns a value for equivalent to do_dialog() (see below):
 * 0: still need to ask for a choice
 * 1: open read-only
 * 2: edit anyway
 * 3: recover
 * 4: delete it
 * 5: quit
 * 6: abort
 */
    static int
do_swapexists(buf, fname)
    buf_T	*buf;
    char_u	*fname;
{
    set_vim_var_string(VV_SWAPNAME, fname, -1);
    set_vim_var_string(VV_SWAPCHOICE, NULL, -1);

    /* Trigger SwapExists autocommands with <afile> set to the file being
     * edited. */
    apply_autocmds(EVENT_SWAPEXISTS, buf->b_fname, NULL, FALSE, NULL);

    set_vim_var_string(VV_SWAPNAME, NULL, -1);

    switch (*get_vim_var_str(VV_SWAPCHOICE))
    {
	case 'o': return 1;
	case 'e': return 2;
	case 'r': return 3;
	case 'd': return 4;
	case 'q': return 5;
	case 'a': return 6;
    }

    return 0;
}
#endif

/*
 * Find out what name to use for the swap file for buffer 'buf'.
 *
 * Several names are tried to find one that does not exist
 * Returns the name in allocated memory or NULL.
 *
 * Note: If BASENAMELEN is not correct, you will get error messages for
 *	 not being able to open the swapfile
 */
    static char_u *
findswapname(buf, dirp, old_fname)
    buf_T	*buf;
    char_u	**dirp;		/* pointer to list of directories */
    char_u	*old_fname;	/* don't give warning for this file name */
{
    char_u	*fname;
    int		n;
    char_u	*dir_name;
#ifdef AMIGA
    BPTR	fh;
#endif
#ifndef SHORT_FNAME
    int		r;
#endif

#if !defined(SHORT_FNAME) \
		     && ((!defined(UNIX) && !defined(OS2)) || defined(ARCHIE))
# define CREATE_DUMMY_FILE
    FILE	*dummyfd = NULL;

/*
 * If we start editing a new file, e.g. "test.doc", which resides on an MSDOS
 * compatible filesystem, it is possible that the file "test.doc.swp" which we
 * create will be exactly the same file. To avoid this problem we temporarily
 * create "test.doc".
 * Don't do this when the check below for a 8.3 file name is used.
 */
    if (!(buf->b_p_sn || buf->b_shortname) && buf->b_fname != NULL
					     && mch_getperm(buf->b_fname) < 0)
	dummyfd = mch_fopen((char *)buf->b_fname, "w");
#endif

/*
 * Isolate a directory name from *dirp and put it in dir_name.
 * First allocate some memory to put the directory name in.
 */
    dir_name = alloc((unsigned)STRLEN(*dirp) + 1);
    if (dir_name != NULL)
	(void)copy_option_part(dirp, dir_name, 31000, ",");

/*
 * we try different names until we find one that does not exist yet
 */
    if (dir_name == NULL)	    /* out of memory */
	fname = NULL;
    else
	fname = makeswapname(buf->b_fname, buf->b_ffname, buf, dir_name);

    for (;;)
    {
	if (fname == NULL)	/* must be out of memory */
	    break;
	if ((n = (int)STRLEN(fname)) == 0)	/* safety check */
	{
	    vim_free(fname);
	    fname = NULL;
	    break;
	}
#if (defined(UNIX) || defined(OS2)) && !defined(ARCHIE) && !defined(SHORT_FNAME)
/*
 * Some systems have a MS-DOS compatible filesystem that use 8.3 character
 * file names. If this is the first try and the swap file name does not fit in
 * 8.3, detect if this is the case, set shortname and try again.
 */
	if (fname[n - 2] == 'w' && fname[n - 1] == 'p'
					&& !(buf->b_p_sn || buf->b_shortname))
	{
	    char_u	    *tail;
	    char_u	    *fname2;
	    struct stat	    s1, s2;
	    int		    f1, f2;
	    int		    created1 = FALSE, created2 = FALSE;
	    int		    same = FALSE;

	    /*
	     * Check if swapfile name does not fit in 8.3:
	     * It either contains two dots, is longer than 8 chars, or starts
	     * with a dot.
	     */
	    tail = gettail(buf->b_fname);
	    if (       vim_strchr(tail, '.') != NULL
		    || STRLEN(tail) > (size_t)8
		    || *gettail(fname) == '.')
	    {
		fname2 = alloc(n + 2);
		if (fname2 != NULL)
		{
		    STRCPY(fname2, fname);
		    /* if fname == "xx.xx.swp",	    fname2 = "xx.xx.swx"
		     * if fname == ".xx.swp",	    fname2 = ".xx.swpx"
		     * if fname == "123456789.swp", fname2 = "12345678x.swp"
		     */
		    if (vim_strchr(tail, '.') != NULL)
			fname2[n - 1] = 'x';
		    else if (*gettail(fname) == '.')
		    {
			fname2[n] = 'x';
			fname2[n + 1] = NUL;
		    }
		    else
			fname2[n - 5] += 1;
		    /*
		     * may need to create the files to be able to use mch_stat()
		     */
		    f1 = mch_open((char *)fname, O_RDONLY | O_EXTRA, 0);
		    if (f1 < 0)
		    {
			f1 = mch_open_rw((char *)fname,
					       O_RDWR|O_CREAT|O_EXCL|O_EXTRA);
#if defined(OS2)
			if (f1 < 0 && errno == ENOENT)
			    same = TRUE;
#endif
			created1 = TRUE;
		    }
		    if (f1 >= 0)
		    {
			f2 = mch_open((char *)fname2, O_RDONLY | O_EXTRA, 0);
			if (f2 < 0)
			{
			    f2 = mch_open_rw((char *)fname2,
					       O_RDWR|O_CREAT|O_EXCL|O_EXTRA);
			    created2 = TRUE;
			}
			if (f2 >= 0)
			{
			    /*
			     * Both files exist now. If mch_stat() returns the
			     * same device and inode they are the same file.
			     */
			    if (mch_fstat(f1, &s1) != -1
				    && mch_fstat(f2, &s2) != -1
				    && s1.st_dev == s2.st_dev
				    && s1.st_ino == s2.st_ino)
				same = TRUE;
			    close(f2);
			    if (created2)
				mch_remove(fname2);
			}
			close(f1);
			if (created1)
			    mch_remove(fname);
		    }
		    vim_free(fname2);
		    if (same)
		    {
			buf->b_shortname = TRUE;
			vim_free(fname);
			fname = makeswapname(buf->b_fname, buf->b_ffname,
							       buf, dir_name);
			continue;	/* try again with b_shortname set */
		    }
		}
	    }
	}
#endif
	/*
	 * check if the swapfile already exists
	 */
	if (mch_getperm(fname) < 0)	/* it does not exist */
	{
#ifdef HAVE_LSTAT
	    struct stat sb;

	    /*
	     * Extra security check: When a swap file is a symbolic link, this
	     * is most likely a symlink attack.
	     */
	    if (mch_lstat((char *)fname, &sb) < 0)
#else
# ifdef AMIGA
	    fh = Open((UBYTE *)fname, (long)MODE_NEWFILE);
	    /*
	     * on the Amiga mch_getperm() will return -1 when the file exists
	     * but is being used by another program. This happens if you edit
	     * a file twice.
	     */
	    if (fh != (BPTR)NULL)	/* can open file, OK */
	    {
		Close(fh);
		mch_remove(fname);
		break;
	    }
	    if (IoErr() != ERROR_OBJECT_IN_USE
					    && IoErr() != ERROR_OBJECT_EXISTS)
# endif
#endif
		break;
	}

	/*
	 * A file name equal to old_fname is OK to use.
	 */
	if (old_fname != NULL && fnamecmp(fname, old_fname) == 0)
	    break;

	/*
	 * get here when file already exists
	 */
	if (fname[n - 2] == 'w' && fname[n - 1] == 'p')	/* first try */
	{
#ifndef SHORT_FNAME
	    /*
	     * on MS-DOS compatible filesystems (e.g. messydos) file.doc.swp
	     * and file.doc are the same file. To guess if this problem is
	     * present try if file.doc.swx exists. If it does, we set
	     * buf->b_shortname and try file_doc.swp (dots replaced by
	     * underscores for this file), and try again. If it doesn't we
	     * assume that "file.doc.swp" already exists.
	     */
	    if (!(buf->b_p_sn || buf->b_shortname))	/* not tried yet */
	    {
		fname[n - 1] = 'x';
		r = mch_getperm(fname);		/* try "file.swx" */
		fname[n - 1] = 'p';
		if (r >= 0)		    /* "file.swx" seems to exist */
		{
		    buf->b_shortname = TRUE;
		    vim_free(fname);
		    fname = makeswapname(buf->b_fname, buf->b_ffname,
							       buf, dir_name);
		    continue;	    /* try again with '.' replaced with '_' */
		}
	    }
#endif
	    /*
	     * If we get here the ".swp" file really exists.
	     * Give an error message, unless recovering, no file name, we are
	     * viewing a help file or when the path of the file is different
	     * (happens when all .swp files are in one directory).
	     */
	    if (!recoverymode && buf->b_fname != NULL
				&& !buf->b_help && !(buf->b_flags & BF_DUMMY))
	    {
		int		fd;
		struct block0	b0;
		int		differ = FALSE;

		/*
		 * Try to read block 0 from the swap file to get the original
		 * file name (and inode number).
		 */
		fd = mch_open((char *)fname, O_RDONLY | O_EXTRA, 0);
		if (fd >= 0)
		{
		    if (read(fd, (char *)&b0, sizeof(b0)) == sizeof(b0))
		    {
			/*
			 * If the swapfile has the same directory as the
			 * buffer don't compare the directory names, they can
			 * have a different mountpoint.
			 */
			if (b0.b0_flags & B0_SAME_DIR)
			{
			    if (fnamecmp(gettail(buf->b_ffname),
						   gettail(b0.b0_fname)) != 0
				    || !same_directory(fname, buf->b_ffname))
			    {
#ifdef CHECK_INODE
				/* Symlinks may point to the same file even
				 * when the name differs, need to check the
				 * inode too. */
				expand_env(b0.b0_fname, NameBuff, MAXPATHL);
				if (fnamecmp_ino(buf->b_ffname, NameBuff,
						     char_to_long(b0.b0_ino)))
#endif
				    differ = TRUE;
			    }
			}
			else
			{
			    /*
			     * The name in the swap file may be
			     * "~user/path/file".  Expand it first.
			     */
			    expand_env(b0.b0_fname, NameBuff, MAXPATHL);
#ifdef CHECK_INODE
			    if (fnamecmp_ino(buf->b_ffname, NameBuff,
						     char_to_long(b0.b0_ino)))
				differ = TRUE;
#else
			    if (fnamecmp(NameBuff, buf->b_ffname) != 0)
				differ = TRUE;
#endif
			}
		    }
		    close(fd);
		}
#ifdef RISCOS
		else
		    /* Can't open swap file, though it does exist.
		     * Assume that the user is editing two files with
		     * the same name in different directories. No error.
		     */
		    differ = TRUE;
#endif

		/* give the ATTENTION message when there is an old swap file
		 * for the current file, and the buffer was not recovered. */
		if (differ == FALSE && !(curbuf->b_flags & BF_RECOVERED)
			&& vim_strchr(p_shm, SHM_ATTENTION) == NULL)
		{
#if defined(HAS_SWAP_EXISTS_ACTION)
		    int		choice = 0;
#endif
#ifdef CREATE_DUMMY_FILE
		    int		did_use_dummy = FALSE;

		    /* Avoid getting a warning for the file being created
		     * outside of Vim, it was created at the start of this
		     * function.  Delete the file now, because Vim might exit
		     * here if the window is closed. */
		    if (dummyfd != NULL)
		    {
			fclose(dummyfd);
			dummyfd = NULL;
			mch_remove(buf->b_fname);
			did_use_dummy = TRUE;
		    }
#endif

#if (defined(UNIX) || defined(__EMX__) || defined(VMS)) && (defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG))
		    process_still_running = FALSE;
#endif
#ifdef FEAT_AUTOCMD
		    /*
		     * If there is an SwapExists autocommand and we can handle
		     * the response, trigger it.  It may return 0 to ask the
		     * user anyway.
		     */
		    if (swap_exists_action != SEA_NONE
			    && has_autocmd(EVENT_SWAPEXISTS, buf->b_fname, buf))
			choice = do_swapexists(buf, fname);

		    if (choice == 0)
#endif
		    {
#ifdef FEAT_GUI
			/* If we are supposed to start the GUI but it wasn't
			 * completely started yet, start it now.  This makes
			 * the messages displayed in the Vim window when
			 * loading a session from the .gvimrc file. */
			if (gui.starting && !gui.in_use)
			    gui_start();
#endif
			/* Show info about the existing swap file. */
			attention_message(buf, fname);

			/* We don't want a 'q' typed at the more-prompt
			 * interrupt loading a file. */
			got_int = FALSE;
		    }

#if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
		    if (swap_exists_action != SEA_NONE && choice == 0)
		    {
			char_u	*name;

			name = alloc((unsigned)(STRLEN(fname)
				+ STRLEN(_("Swap file \""))
				+ STRLEN(_("\" already exists!")) + 5));
			if (name != NULL)
			{
			    STRCPY(name, _("Swap file \""));
			    home_replace(NULL, fname, name + STRLEN(name),
								  1000, TRUE);
			    STRCAT(name, _("\" already exists!"));
			}
			choice = do_dialog(VIM_WARNING,
				    (char_u *)_("VIM - ATTENTION"),
				    name == NULL
					?  (char_u *)_("Swap file already exists!")
					: name,
# if defined(UNIX) || defined(__EMX__) || defined(VMS)
				    process_still_running
					? (char_u *)_("&Open Read-Only\n&Edit anyway\n&Recover\n&Quit\n&Abort") :
# endif
					(char_u *)_("&Open Read-Only\n&Edit anyway\n&Recover\n&Delete it\n&Quit\n&Abort"), 1, NULL);

# if defined(UNIX) || defined(__EMX__) || defined(VMS)
			if (process_still_running && choice >= 4)
			    choice++;	/* Skip missing "Delete it" button */
# endif
			vim_free(name);

			/* pretend screen didn't scroll, need redraw anyway */
			msg_scrolled = 0;
			redraw_all_later(NOT_VALID);
		    }
#endif

#if defined(HAS_SWAP_EXISTS_ACTION)
		    if (choice > 0)
		    {
			switch (choice)
			{
			    case 1:
				buf->b_p_ro = TRUE;
				break;
			    case 2:
				break;
			    case 3:
				swap_exists_action = SEA_RECOVER;
				break;
			    case 4:
				mch_remove(fname);
				break;
			    case 5:
				swap_exists_action = SEA_QUIT;
				break;
			    case 6:
				swap_exists_action = SEA_QUIT;
				got_int = TRUE;
				break;
			}

			/* If the file was deleted this fname can be used. */
			if (mch_getperm(fname) < 0)
			    break;
		    }
		    else
#endif
		    {
			MSG_PUTS("\n");
			if (msg_silent == 0)
			    /* call wait_return() later */
			    need_wait_return = TRUE;
		    }

#ifdef CREATE_DUMMY_FILE
		    /* Going to try another name, need the dummy file again. */
		    if (did_use_dummy)
			dummyfd = mch_fopen((char *)buf->b_fname, "w");
#endif
		}
	    }
	}

	/*
	 * Change the ".swp" extension to find another file that can be used.
	 * First decrement the last char: ".swo", ".swn", etc.
	 * If that still isn't enough decrement the last but one char: ".svz"
	 * Can happen when editing many "No Name" buffers.
	 */
	if (fname[n - 1] == 'a')	/* ".s?a" */
	{
	    if (fname[n - 2] == 'a')    /* ".saa": tried enough, give up */
	    {
		EMSG(_("E326: Too many swap files found"));
		vim_free(fname);
		fname = NULL;
		break;
	    }
	    --fname[n - 2];		/* ".svz", ".suz", etc. */
	    fname[n - 1] = 'z' + 1;
	}
	--fname[n - 1];			/* ".swo", ".swn", etc. */
    }

    vim_free(dir_name);
#ifdef CREATE_DUMMY_FILE
    if (dummyfd != NULL)	/* file has been created temporarily */
    {
	fclose(dummyfd);
	mch_remove(buf->b_fname);
    }
#endif
    return fname;
}

    static int
b0_magic_wrong(b0p)
    ZERO_BL *b0p;
{
    return (b0p->b0_magic_long != (long)B0_MAGIC_LONG
	    || b0p->b0_magic_int != (int)B0_MAGIC_INT
	    || b0p->b0_magic_short != (short)B0_MAGIC_SHORT
	    || b0p->b0_magic_char != B0_MAGIC_CHAR);
}

#ifdef CHECK_INODE
/*
 * Compare current file name with file name from swap file.
 * Try to use inode numbers when possible.
 * Return non-zero when files are different.
 *
 * When comparing file names a few things have to be taken into consideration:
 * - When working over a network the full path of a file depends on the host.
 *   We check the inode number if possible.  It is not 100% reliable though,
 *   because the device number cannot be used over a network.
 * - When a file does not exist yet (editing a new file) there is no inode
 *   number.
 * - The file name in a swap file may not be valid on the current host.  The
 *   "~user" form is used whenever possible to avoid this.
 *
 * This is getting complicated, let's make a table:
 *
 *		ino_c  ino_s  fname_c  fname_s	differ =
 *
 * both files exist -> compare inode numbers:
 *		!= 0   != 0	X	 X	ino_c != ino_s
 *
 * inode number(s) unknown, file names available -> compare file names
 *		== 0	X	OK	 OK	fname_c != fname_s
 *		 X     == 0	OK	 OK	fname_c != fname_s
 *
 * current file doesn't exist, file for swap file exist, file name(s) not
 * available -> probably different
 *		== 0   != 0    FAIL	 X	TRUE
 *		== 0   != 0	X	FAIL	TRUE
 *
 * current file exists, inode for swap unknown, file name(s) not
 * available -> probably different
 *		!= 0   == 0    FAIL	 X	TRUE
 *		!= 0   == 0	X	FAIL	TRUE
 *
 * current file doesn't exist, inode for swap unknown, one file name not
 * available -> probably different
 *		== 0   == 0    FAIL	 OK	TRUE
 *		== 0   == 0	OK	FAIL	TRUE
 *
 * current file doesn't exist, inode for swap unknown, both file names not
 * available -> probably same file
 *		== 0   == 0    FAIL	FAIL	FALSE
 *
 * Note that when the ino_t is 64 bits, only the last 32 will be used.  This
 * can't be changed without making the block 0 incompatible with 32 bit
 * versions.
 */

    static int
fnamecmp_ino(fname_c, fname_s, ino_block0)
    char_u	*fname_c;	    /* current file name */
    char_u	*fname_s;	    /* file name from swap file */
    long	ino_block0;
{
    struct stat	st;
    ino_t	ino_c = 0;	    /* ino of current file */
    ino_t	ino_s;		    /* ino of file from swap file */
    char_u	buf_c[MAXPATHL];    /* full path of fname_c */
    char_u	buf_s[MAXPATHL];    /* full path of fname_s */
    int		retval_c;	    /* flag: buf_c valid */
    int		retval_s;	    /* flag: buf_s valid */

    if (mch_stat((char *)fname_c, &st) == 0)
	ino_c = (ino_t)st.st_ino;

    /*
     * First we try to get the inode from the file name, because the inode in
     * the swap file may be outdated.  If that fails (e.g. this path is not
     * valid on this machine), use the inode from block 0.
     */
    if (mch_stat((char *)fname_s, &st) == 0)
	ino_s = (ino_t)st.st_ino;
    else
	ino_s = (ino_t)ino_block0;

    if (ino_c && ino_s)
	return (ino_c != ino_s);

    /*
     * One of the inode numbers is unknown, try a forced vim_FullName() and
     * compare the file names.
     */
    retval_c = vim_FullName(fname_c, buf_c, MAXPATHL, TRUE);
    retval_s = vim_FullName(fname_s, buf_s, MAXPATHL, TRUE);
    if (retval_c == OK && retval_s == OK)
	return (STRCMP(buf_c, buf_s) != 0);

    /*
     * Can't compare inodes or file names, guess that the files are different,
     * unless both appear not to exist at all.
     */
    if (ino_s == 0 && ino_c == 0 && retval_c == FAIL && retval_s == FAIL)
	return FALSE;
    return TRUE;
}
#endif /* CHECK_INODE */

/*
 * Move a long integer into a four byte character array.
 * Used for machine independency in block zero.
 */
    static void
long_to_char(n, s)
    long    n;
    char_u  *s;
{
    s[0] = (char_u)(n & 0xff);
    n = (unsigned)n >> 8;
    s[1] = (char_u)(n & 0xff);
    n = (unsigned)n >> 8;
    s[2] = (char_u)(n & 0xff);
    n = (unsigned)n >> 8;
    s[3] = (char_u)(n & 0xff);
}

    static long
char_to_long(s)
    char_u  *s;
{
    long    retval;

    retval = s[3];
    retval <<= 8;
    retval |= s[2];
    retval <<= 8;
    retval |= s[1];
    retval <<= 8;
    retval |= s[0];

    return retval;
}

/*
 * Set the flags in the first block of the swap file:
 * - file is modified or not: buf->b_changed
 * - 'fileformat'
 * - 'fileencoding'
 */
    void
ml_setflags(buf)
    buf_T	*buf;
{
    bhdr_T	*hp;
    ZERO_BL	*b0p;

    if (!buf->b_ml.ml_mfp)
	return;
    for (hp = buf->b_ml.ml_mfp->mf_used_last; hp != NULL; hp = hp->bh_prev)
    {
	if (hp->bh_bnum == 0)
	{
	    b0p = (ZERO_BL *)(hp->bh_data);
	    b0p->b0_dirty = buf->b_changed ? B0_DIRTY : 0;
	    b0p->b0_flags = (b0p->b0_flags & ~B0_FF_MASK)
						  | (get_fileformat(buf) + 1);
#ifdef FEAT_MBYTE
	    add_b0_fenc(b0p, buf);
#endif
	    hp->bh_flags |= BH_DIRTY;
	    mf_sync(buf->b_ml.ml_mfp, MFS_ZERO);
	    break;
	}
    }
}

#if defined(FEAT_BYTEOFF) || defined(PROTO)

#define MLCS_MAXL 800	/* max no of lines in chunk */
#define MLCS_MINL 400   /* should be half of MLCS_MAXL */

/*
 * Keep information for finding byte offset of a line, updtytpe may be one of:
 * ML_CHNK_ADDLINE: Add len to parent chunk, possibly splitting it
 *	   Careful: ML_CHNK_ADDLINE may cause ml_find_line() to be called.
 * ML_CHNK_DELLINE: Subtract len from parent chunk, possibly deleting it
 * ML_CHNK_UPDLINE: Add len to parent chunk, as a signed entity.
 */
    static void
ml_updatechunk(buf, line, len, updtype)
    buf_T	*buf;
    linenr_T	line;
    long	len;
    int		updtype;
{
    static buf_T	*ml_upd_lastbuf = NULL;
    static linenr_T	ml_upd_lastline;
    static linenr_T	ml_upd_lastcurline;
    static int		ml_upd_lastcurix;

    linenr_T		curline = ml_upd_lastcurline;
    int			curix = ml_upd_lastcurix;
    long		size;
    chunksize_T		*curchnk;
    int			rest;
    bhdr_T		*hp;
    DATA_BL		*dp;

    if (buf->b_ml.ml_usedchunks == -1 || len == 0)
	return;
    if (buf->b_ml.ml_chunksize == NULL)
    {
	buf->b_ml.ml_chunksize = (chunksize_T *)
				  alloc((unsigned)sizeof(chunksize_T) * 100);
	if (buf->b_ml.ml_chunksize == NULL)
	{
	    buf->b_ml.ml_usedchunks = -1;
	    return;
	}
	buf->b_ml.ml_numchunks = 100;
	buf->b_ml.ml_usedchunks = 1;
	buf->b_ml.ml_chunksize[0].mlcs_numlines = 1;
	buf->b_ml.ml_chunksize[0].mlcs_totalsize = 1;
    }

    if (updtype == ML_CHNK_UPDLINE && buf->b_ml.ml_line_count == 1)
    {
	/*
	 * First line in empty buffer from ml_flush_line() -- reset
	 */
	buf->b_ml.ml_usedchunks = 1;
	buf->b_ml.ml_chunksize[0].mlcs_numlines = 1;
	buf->b_ml.ml_chunksize[0].mlcs_totalsize =
				  (long)STRLEN(buf->b_ml.ml_line_ptr) + 1;
	return;
    }

    /*
     * Find chunk that our line belongs to, curline will be at start of the
     * chunk.
     */
    if (buf != ml_upd_lastbuf || line != ml_upd_lastline + 1
	    || updtype != ML_CHNK_ADDLINE)
    {
	for (curline = 1, curix = 0;
	     curix < buf->b_ml.ml_usedchunks - 1
	     && line >= curline + buf->b_ml.ml_chunksize[curix].mlcs_numlines;
	     curix++)
	{
	    curline += buf->b_ml.ml_chunksize[curix].mlcs_numlines;
	}
    }
    else if (line >= curline + buf->b_ml.ml_chunksize[curix].mlcs_numlines
		 && curix < buf->b_ml.ml_usedchunks - 1)
    {
	/* Adjust cached curix & curline */
	curline += buf->b_ml.ml_chunksize[curix].mlcs_numlines;
	curix++;
    }
    curchnk = buf->b_ml.ml_chunksize + curix;

    if (updtype == ML_CHNK_DELLINE)
	len = -len;
    curchnk->mlcs_totalsize += len;
    if (updtype == ML_CHNK_ADDLINE)
    {
	curchnk->mlcs_numlines++;

	/* May resize here so we don't have to do it in both cases below */
	if (buf->b_ml.ml_usedchunks + 1 >= buf->b_ml.ml_numchunks)
	{
	    buf->b_ml.ml_numchunks = buf->b_ml.ml_numchunks * 3 / 2;
	    buf->b_ml.ml_chunksize = (chunksize_T *)
		vim_realloc(buf->b_ml.ml_chunksize,
			    sizeof(chunksize_T) * buf->b_ml.ml_numchunks);
	    if (buf->b_ml.ml_chunksize == NULL)
	    {
		/* Hmmmm, Give up on offset for this buffer */
		buf->b_ml.ml_usedchunks = -1;
		return;
	    }
	}

	if (buf->b_ml.ml_chunksize[curix].mlcs_numlines >= MLCS_MAXL)
	{
	    int	    count;	    /* number of entries in block */
	    int	    idx;
	    int	    text_end;
	    int	    linecnt;

	    mch_memmove(buf->b_ml.ml_chunksize + curix + 1,
			buf->b_ml.ml_chunksize + curix,
			(buf->b_ml.ml_usedchunks - curix) *
			sizeof(chunksize_T));
	    /* Compute length of first half of lines in the splitted chunk */
	    size = 0;
	    linecnt = 0;
	    while (curline < buf->b_ml.ml_line_count
			&& linecnt < MLCS_MINL)
	    {
		if ((hp = ml_find_line(buf, curline, ML_FIND)) == NULL)
		{
		    buf->b_ml.ml_usedchunks = -1;
		    return;
		}
		dp = (DATA_BL *)(hp->bh_data);
		count = (long)(buf->b_ml.ml_locked_high) -
			(long)(buf->b_ml.ml_locked_low) + 1;
		idx = curline - buf->b_ml.ml_locked_low;
		curline = buf->b_ml.ml_locked_high + 1;
		if (idx == 0)/* first line in block, text at the end */
		    text_end = dp->db_txt_end;
		else
		    text_end = ((dp->db_index[idx - 1]) & DB_INDEX_MASK);
		/* Compute index of last line to use in this MEMLINE */
		rest = count - idx;
		if (linecnt + rest > MLCS_MINL)
		{
		    idx += MLCS_MINL - linecnt - 1;
		    linecnt = MLCS_MINL;
		}
		else
		{
		    idx = count - 1;
		    linecnt += rest;
		}
		size += text_end - ((dp->db_index[idx]) & DB_INDEX_MASK);
	    }
	    buf->b_ml.ml_chunksize[curix].mlcs_numlines = linecnt;
	    buf->b_ml.ml_chunksize[curix + 1].mlcs_numlines -= linecnt;
	    buf->b_ml.ml_chunksize[curix].mlcs_totalsize = size;
	    buf->b_ml.ml_chunksize[curix + 1].mlcs_totalsize -= size;
	    buf->b_ml.ml_usedchunks++;
	    ml_upd_lastbuf = NULL;   /* Force recalc of curix & curline */
	    return;
	}
	else if (buf->b_ml.ml_chunksize[curix].mlcs_numlines >= MLCS_MINL
		     && curix == buf->b_ml.ml_usedchunks - 1
		     && buf->b_ml.ml_line_count - line <= 1)
	{
	    /*
	     * We are in the last chunk and it is cheap to crate a new one
	     * after this. Do it now to avoid the loop above later on
	     */
	    curchnk = buf->b_ml.ml_chunksize + curix + 1;
	    buf->b_ml.ml_usedchunks++;
	    if (line == buf->b_ml.ml_line_count)
	    {
		curchnk->mlcs_numlines = 0;
		curchnk->mlcs_totalsize = 0;
	    }
	    else
	    {
		/*
		 * Line is just prior to last, move count for last
		 * This is the common case  when loading a new file
		 */
		hp = ml_find_line(buf, buf->b_ml.ml_line_count, ML_FIND);
		if (hp == NULL)
		{
		    buf->b_ml.ml_usedchunks = -1;
		    return;
		}
		dp = (DATA_BL *)(hp->bh_data);
		if (dp->db_line_count == 1)
		    rest = dp->db_txt_end - dp->db_txt_start;
		else
		    rest =
			((dp->db_index[dp->db_line_count - 2]) & DB_INDEX_MASK)
			- dp->db_txt_start;
		curchnk->mlcs_totalsize = rest;
		curchnk->mlcs_numlines = 1;
		curchnk[-1].mlcs_totalsize -= rest;
		curchnk[-1].mlcs_numlines -= 1;
	    }
	}
    }
    else if (updtype == ML_CHNK_DELLINE)
    {
	curchnk->mlcs_numlines--;
	ml_upd_lastbuf = NULL;   /* Force recalc of curix & curline */
	if (curix < (buf->b_ml.ml_usedchunks - 1)
		&& (curchnk->mlcs_numlines + curchnk[1].mlcs_numlines)
		   <= MLCS_MINL)
	{
	    curix++;
	    curchnk = buf->b_ml.ml_chunksize + curix;
	}
	else if (curix == 0 && curchnk->mlcs_numlines <= 0)
	{
	    buf->b_ml.ml_usedchunks--;
	    mch_memmove(buf->b_ml.ml_chunksize, buf->b_ml.ml_chunksize + 1,
			buf->b_ml.ml_usedchunks * sizeof(chunksize_T));
	    return;
	}
	else if (curix == 0 || (curchnk->mlcs_numlines > 10
		    && (curchnk->mlcs_numlines + curchnk[-1].mlcs_numlines)
		       > MLCS_MINL))
	{
	    return;
	}

	/* Collapse chunks */
	curchnk[-1].mlcs_numlines += curchnk->mlcs_numlines;
	curchnk[-1].mlcs_totalsize += curchnk->mlcs_totalsize;
	buf->b_ml.ml_usedchunks--;
	if (curix < buf->b_ml.ml_usedchunks)
	{
	    mch_memmove(buf->b_ml.ml_chunksize + curix,
			buf->b_ml.ml_chunksize + curix + 1,
			(buf->b_ml.ml_usedchunks - curix) *
			sizeof(chunksize_T));
	}
	return;
    }
    ml_upd_lastbuf = buf;
    ml_upd_lastline = line;
    ml_upd_lastcurline = curline;
    ml_upd_lastcurix = curix;
}

/*
 * Find offset for line or line with offset.
 * Find line with offset if "lnum" is 0; return remaining offset in offp
 * Find offset of line if "lnum" > 0
 * return -1 if information is not available
 */
    long
ml_find_line_or_offset(buf, lnum, offp)
    buf_T	*buf;
    linenr_T	lnum;
    long	*offp;
{
    linenr_T	curline;
    int		curix;
    long	size;
    bhdr_T	*hp;
    DATA_BL	*dp;
    int		count;		/* number of entries in block */
    int		idx;
    int		start_idx;
    int		text_end;
    long	offset;
    int		len;
    int		ffdos = (get_fileformat(buf) == EOL_DOS);
    int		extra = 0;

    /* take care of cached line first */
    ml_flush_line(curbuf);

    if (buf->b_ml.ml_usedchunks == -1
	    || buf->b_ml.ml_chunksize == NULL
	    || lnum < 0)
	return -1;

    if (offp == NULL)
	offset = 0;
    else
	offset = *offp;
    if (lnum == 0 && offset <= 0)
	return 1;   /* Not a "find offset" and offset 0 _must_ be in line 1 */
    /*
     * Find the last chunk before the one containing our line. Last chunk is
     * special because it will never qualify
     */
    curline = 1;
    curix = size = 0;
    while (curix < buf->b_ml.ml_usedchunks - 1
	    && ((lnum != 0
	     && lnum >= curline + buf->b_ml.ml_chunksize[curix].mlcs_numlines)
		|| (offset != 0
	       && offset > size + buf->b_ml.ml_chunksize[curix].mlcs_totalsize
		      + ffdos * buf->b_ml.ml_chunksize[curix].mlcs_numlines)))
    {
	curline += buf->b_ml.ml_chunksize[curix].mlcs_numlines;
	size += buf->b_ml.ml_chunksize[curix].mlcs_totalsize;
	if (offset && ffdos)
	    size += buf->b_ml.ml_chunksize[curix].mlcs_numlines;
	curix++;
    }

    while ((lnum != 0 && curline < lnum) || (offset != 0 && size < offset))
    {
	if (curline > buf->b_ml.ml_line_count
		|| (hp = ml_find_line(buf, curline, ML_FIND)) == NULL)
	    return -1;
	dp = (DATA_BL *)(hp->bh_data);
	count = (long)(buf->b_ml.ml_locked_high) -
		(long)(buf->b_ml.ml_locked_low) + 1;
	start_idx = idx = curline - buf->b_ml.ml_locked_low;
	if (idx == 0)/* first line in block, text at the end */
	    text_end = dp->db_txt_end;
	else
	    text_end = ((dp->db_index[idx - 1]) & DB_INDEX_MASK);
	/* Compute index of last line to use in this MEMLINE */
	if (lnum != 0)
	{
	    if (curline + (count - idx) >= lnum)
		idx += lnum - curline - 1;
	    else
		idx = count - 1;
	}
	else
	{
	    extra = 0;
	    while (offset >= size
		       + text_end - (int)((dp->db_index[idx]) & DB_INDEX_MASK)
								      + ffdos)
	    {
		if (ffdos)
		    size++;
		if (idx == count - 1)
		{
		    extra = 1;
		    break;
		}
		idx++;
	    }
	}
	len = text_end - ((dp->db_index[idx]) & DB_INDEX_MASK);
	size += len;
	if (offset != 0 && size >= offset)
	{
	    if (size + ffdos == offset)
		*offp = 0;
	    else if (idx == start_idx)
		*offp = offset - size + len;
	    else
		*offp = offset - size + len
		     - (text_end - ((dp->db_index[idx - 1]) & DB_INDEX_MASK));
	    curline += idx - start_idx + extra;
	    if (curline > buf->b_ml.ml_line_count)
		return -1;	/* exactly one byte beyond the end */
	    return curline;
	}
	curline = buf->b_ml.ml_locked_high + 1;
    }

    if (lnum != 0)
    {
	/* Count extra CR characters. */
	if (ffdos)
	    size += lnum - 1;

	/* Don't count the last line break if 'bin' and 'noeol'. */
	if (buf->b_p_bin && !buf->b_p_eol)
	    size -= ffdos + 1;
    }

    return size;
}

/*
 * Goto byte in buffer with offset 'cnt'.
 */
    void
goto_byte(cnt)
    long	cnt;
{
    long	boff = cnt;
    linenr_T	lnum;

    ml_flush_line(curbuf);	/* cached line may be dirty */
    setpcmark();
    if (boff)
	--boff;
    lnum = ml_find_line_or_offset(curbuf, (linenr_T)0, &boff);
    if (lnum < 1)	/* past the end */
    {
	curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
	curwin->w_curswant = MAXCOL;
	coladvance((colnr_T)MAXCOL);
    }
    else
    {
	curwin->w_cursor.lnum = lnum;
	curwin->w_cursor.col = (colnr_T)boff;
# ifdef FEAT_VIRTUALEDIT
	curwin->w_cursor.coladd = 0;
# endif
	curwin->w_set_curswant = TRUE;
    }
    check_cursor();

# ifdef FEAT_MBYTE
    /* Make sure the cursor is on the first byte of a multi-byte char. */
    if (has_mbyte)
	mb_adjust_cursor();
# endif
}
#endif