File: t6036-recursive-corner-cases.sh

package info (click to toggle)
git 1:2.20.1-2+deb10u3
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 45,676 kB
  • sloc: ansic: 210,769; sh: 180,432; perl: 29,102; tcl: 21,663; python: 6,143; makefile: 3,700; sed: 189; php: 120; asm: 98; csh: 45; ruby: 24; lisp: 12
file content (1405 lines) | stat: -rwxr-xr-x 33,437 bytes parent folder | download | duplicates (2)
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
#!/bin/sh

test_description='recursive merge corner cases involving criss-cross merges'

. ./test-lib.sh

#
#  L1  L2
#   o---o
#  / \ / \
# o   X   ?
#  \ / \ /
#   o---o
#  R1  R2
#

test_expect_success 'setup basic criss-cross + rename with no modifications' '
	test_create_repo basic-rename &&
	(
		cd basic-rename &&

		ten="0 1 2 3 4 5 6 7 8 9" &&
		for i in $ten
		do
			echo line $i in a sample file
		done >one &&
		for i in $ten
		do
			echo line $i in another sample file
		done >two &&
		git add one two &&
		test_tick && git commit -m initial &&

		git branch L1 &&
		git checkout -b R1 &&
		git mv one three &&
		test_tick && git commit -m R1 &&

		git checkout L1 &&
		git mv two three &&
		test_tick && git commit -m L1 &&

		git checkout L1^0 &&
		test_tick && git merge -s ours R1 &&
		git tag L2 &&

		git checkout R1^0 &&
		test_tick && git merge -s ours L1 &&
		git tag R2
	)
'

test_expect_success 'merge simple rename+criss-cross with no modifications' '
	(
		cd basic-rename &&

		git reset --hard &&
		git checkout L2^0 &&

		test_must_fail git merge -s recursive R2^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&
		git ls-files -o >out &&
		test_line_count = 3 out &&

		git rev-parse >expect       \
			L2:three   R2:three \
			L2:three   R2:three &&
		git rev-parse   >actual     \
			:2:three   :3:three &&
		git hash-object >>actual    \
			three~HEAD three~R2^0 &&
		test_cmp expect actual
	)
'

#
# Same as before, but modify L1 slightly:
#
#  L1m L2
#   o---o
#  / \ / \
# o   X   ?
#  \ / \ /
#   o---o
#  R1  R2
#

test_expect_success 'setup criss-cross + rename merges with basic modification' '
	test_create_repo rename-modify &&
	(
		cd rename-modify &&

		ten="0 1 2 3 4 5 6 7 8 9" &&
		for i in $ten
		do
			echo line $i in a sample file
		done >one &&
		for i in $ten
		do
			echo line $i in another sample file
		done >two &&
		git add one two &&
		test_tick && git commit -m initial &&

		git branch L1 &&
		git checkout -b R1 &&
		git mv one three &&
		echo more >>two &&
		git add two &&
		test_tick && git commit -m R1 &&

		git checkout L1 &&
		git mv two three &&
		test_tick && git commit -m L1 &&

		git checkout L1^0 &&
		test_tick && git merge -s ours R1 &&
		git tag L2 &&

		git checkout R1^0 &&
		test_tick && git merge -s ours L1 &&
		git tag R2
	)
'

test_expect_success 'merge criss-cross + rename merges with basic modification' '
	(
		cd rename-modify &&

		git checkout L2^0 &&

		test_must_fail git merge -s recursive R2^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&
		git ls-files -o >out &&
		test_line_count = 3 out &&

		git rev-parse >expect       \
			L2:three   R2:three \
			L2:three   R2:three &&
		git rev-parse   >actual     \
			:2:three   :3:three &&
		git hash-object >>actual    \
			three~HEAD three~R2^0 &&
		test_cmp expect actual
	)
'

#
# For the next test, we start with three commits in two lines of development
# which setup a rename/add conflict:
#   Commit A: File 'a' exists
#   Commit B: Rename 'a' -> 'new_a'
#   Commit C: Modify 'a', create different 'new_a'
# Later, two different people merge and resolve differently:
#   Commit D: Merge B & C, ignoring separately created 'new_a'
#   Commit E: Merge B & C making use of some piece of secondary 'new_a'
# Finally, someone goes to merge D & E.  Does git detect the conflict?
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#

test_expect_success 'setup differently handled merges of rename/add conflict' '
	test_create_repo rename-add &&
	(
		cd rename-add &&

		printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n" >a &&
		git add a &&
		test_tick && git commit -m A &&

		git branch B &&
		git checkout -b C &&
		echo 10 >>a &&
		echo "other content" >>new_a &&
		git add a new_a &&
		test_tick && git commit -m C &&

		git checkout B &&
		git mv a new_a &&
		test_tick && git commit -m B &&

		git checkout B^0 &&
		test_must_fail git merge C &&
		git clean -f &&
		test_tick && git commit -m D &&
		git tag D &&

		git checkout C^0 &&
		test_must_fail git merge B &&
		rm new_a~HEAD new_a &&
		printf "Incorrectly merged content" >>new_a &&
		git add -u &&
		test_tick && git commit -m E &&
		git tag E
	)
'

test_expect_success 'git detects differently handled merges conflict' '
	(
		cd rename-add &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 3 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		git rev-parse >expect       \
			D:new_a  E:new_a &&
		git rev-parse   >actual     \
			:2:new_a :3:new_a &&
		test_cmp expect actual &&

		git cat-file -p C:new_a >ours &&
		git cat-file -p B:new_a >theirs &&
		>empty &&
		test_must_fail git merge-file \
			-L "Temporary merge branch 1" \
			-L "" \
			-L "Temporary merge branch 2" \
			ours empty theirs &&
		sed -e "s/^\([<=>]\)/\1\1\1/" ours >expect &&
		git cat-file -p :1:new_a >actual &&
		test_cmp expect actual
	)
'

#
# criss-cross + modify/delete:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: file with contents 'A\n'
#   Commit B: file with contents 'B\n'
#   Commit C: file not present
#   Commit D: file with contents 'B\n'
#   Commit E: file not present
#
# Merging commits D & E should result in modify/delete conflict.

test_expect_success 'setup criss-cross + modify/delete resolved differently' '
	test_create_repo modify-delete &&
	(
		cd modify-delete &&

		echo A >file &&
		git add file &&
		test_tick &&
		git commit -m A &&

		git branch B &&
		git checkout -b C &&
		git rm file &&
		test_tick &&
		git commit -m C &&

		git checkout B &&
		echo B >file &&
		git add file &&
		test_tick &&
		git commit -m B &&

		git checkout B^0 &&
		test_must_fail git merge C &&
		echo B >file &&
		git add file &&
		test_tick &&
		git commit -m D &&
		git tag D &&

		git checkout C^0 &&
		test_must_fail git merge B &&
		git rm file &&
		test_tick &&
		git commit -m E &&
		git tag E
	)
'

test_expect_success 'git detects conflict merging criss-cross+modify/delete' '
	(
		cd modify-delete &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&

		git rev-parse >expect       \
			master:file  B:file &&
		git rev-parse   >actual      \
			:1:file      :2:file &&
		test_cmp expect actual
	)
'

test_expect_success 'git detects conflict merging criss-cross+modify/delete, reverse direction' '
	(
		cd modify-delete &&

		git reset --hard &&
		git checkout E^0 &&

		test_must_fail git merge -s recursive D^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&

		git rev-parse >expect       \
			master:file  B:file &&
		git rev-parse   >actual      \
			:1:file      :3:file &&
		test_cmp expect actual
	)
'

#      SORRY FOR THE SUPER LONG DESCRIPTION, BUT THIS NEXT ONE IS HAIRY
#
# criss-cross + d/f conflict via add/add:
#   Commit A: Neither file 'a' nor directory 'a/' exists.
#   Commit B: Introduce 'a'
#   Commit C: Introduce 'a/file'
#   Commit D1: Merge B & C, keeping 'a'    and deleting 'a/'
#   Commit E1: Merge B & C, deleting 'a' but keeping 'a/file'
#
#      B   D1 or D2
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E1 or E2 or E3
#
# I'll describe D2, E2, & E3 (which are alternatives for D1 & E1) more below...
#
# Merging D1 & E1 requires we first create a virtual merge base X from
# merging A & B in memory.  There are several possibilities for the merge-base:
#   1: Keep both 'a' and 'a/file' (assuming crazy filesystem allowing a tree
#      with a directory and file at same path): results in merge of D1 & E1
#      being clean with both files deleted.  Bad (no conflict detected).
#   2: Keep 'a' but not 'a/file': Merging D1 & E1 is clean and matches E1.  Bad.
#   3: Keep 'a/file' but not 'a': Merging D1 & E1 is clean and matches D1.  Bad.
#   4: Keep neither file: Merging D1 & E1 reports the D/F add/add conflict.
#
# So 4 sounds good for this case, but if we were to merge D1 & E3, where E3
# is defined as:
#   Commit E3: Merge B & C, keeping modified a, and deleting a/
# then we'd get an add/add conflict for 'a', which seems suboptimal.  A little
# creativity leads us to an alternate choice:
#   5: Keep 'a' as 'a~$UNIQUE' and a/file; results:
#        Merge D1 & E1: rename/delete conflict for 'a'; a/file silently deleted
#        Merge D1 & E3 is clean, as expected.
#
# So choice 5 at least provides some kind of conflict for the original case,
# and can merge cleanly as expected with D1 and E3.  It also made things just
# slightly funny for merging D1 and e$, where E4 is defined as:
#   Commit E4: Merge B & C, modifying 'a' and renaming to 'a2', and deleting 'a/'
# in this case, we'll get a rename/rename(1to2) conflict because a~$UNIQUE
# gets renamed to 'a' in D1 and to 'a2' in E4.  But that's better than having
# two files (both 'a' and 'a2') sitting around without the user being notified
# that we could detect they were related and need to be merged.  Also, choice
# 5 makes the handling of 'a/file' seem suboptimal.  What if we were to merge
# D2 and E4, where D2 is:
#   Commit D2: Merge B & C, renaming 'a'->'a2', keeping 'a/file'
# This would result in a clean merge with 'a2' having three-way merged
# contents (good), and deleting 'a/' (bad) -- it doesn't detect the
# conflict in how the different sides treated a/file differently.
# Continuing down the creative route:
#   6: Keep 'a' as 'a~$UNIQUE1' and keep 'a/' as 'a~$UNIQUE2/'; results:
#        Merge D1 & E1: rename/delete conflict for 'a' and each path under 'a/'.
#        Merge D1 & E3: clean, as expected.
#        Merge D1 & E4: rename/rename(1to2) conflict on 'a' vs 'a2'.
#        Merge D2 & E4: clean for 'a2', rename/delete for a/file
#
# Choice 6 could cause rename detection to take longer (providing more targets
# that need to be searched).  Also, the conflict message for each path under
# 'a/' might be annoying unless we can detect it at the directory level, print
# it once, and then suppress it for individual filepaths underneath.
#
#
# As of time of writing, git uses choice 5.  Directory rename detection and
# rename detection performance improvements might make choice 6 a desirable
# improvement.  But we can at least document where we fall short for now...
#
#
# Historically, this testcase also used:
#   Commit E2: Merge B & C, deleting 'a' but keeping slightly modified 'a/file'
# The merge of D1 & E2 is very similar to D1 & E1 -- it has similar issues for
# path 'a', but should always result in a modify/delete conflict for path
# 'a/file'.  These tests ran the two merges
#   D1 & E1
#   D1 & E2
# in both directions, to check for directional issues with D/F conflict
# handling. Later we added
#   D1 & E3
#   D1 & E4
#   D2 & E4
# for good measure, though we only ran those one way because we had pretty
# good confidence in merge-recursive's directional handling of D/F issues.
#
# Just to summarize all the intermediate merge commits:
#   Commit D1: Merge B & C, keeping a    and deleting a/
#   Commit D2: Merge B & C, renaming a->a2, keeping a/file
#   Commit E1: Merge B & C, deleting a but keeping a/file
#   Commit E2: Merge B & C, deleting a but keeping slightly modified a/file
#   Commit E3: Merge B & C, keeping modified a, and deleting a/
#   Commit E4: Merge B & C, modifying 'a' and renaming to 'a2', and deleting 'a/'
#

test_expect_success 'setup differently handled merges of directory/file conflict' '
	test_create_repo directory-file &&
	(
		cd directory-file &&

		>ignore-me &&
		git add ignore-me &&
		test_tick &&
		git commit -m A &&
		git tag A &&

		git branch B &&
		git checkout -b C &&
		mkdir a &&
		test_write_lines a b c d e f g >a/file &&
		git add a/file &&
		test_tick &&
		git commit -m C &&

		git checkout B &&
		test_write_lines 1 2 3 4 5 6 7 >a &&
		git add a &&
		test_tick &&
		git commit -m B &&

		git checkout B^0 &&
		git merge -s ours -m D1 C^0 &&
		git tag D1 &&

		git checkout B^0 &&
		test_must_fail git merge C^0 &&
		git clean -fd &&
		git rm -rf a/ &&
		git rm a &&
		git cat-file -p B:a >a2 &&
		git add a2 &&
		git commit -m D2 &&
		git tag D2 &&

		git checkout C^0 &&
		git merge -s ours -m E1 B^0 &&
		git tag E1 &&

		git checkout C^0 &&
		git merge -s ours -m E2 B^0 &&
		test_write_lines a b c d e f g h >a/file &&
		git add a/file &&
		git commit --amend -C HEAD &&
		git tag E2 &&

		git checkout C^0 &&
		test_must_fail git merge B^0 &&
		git clean -fd &&
		git rm -rf a/ &&
		test_write_lines 1 2 3 4 5 6 7 8 >a &&
		git add a &&
		git commit -m E3 &&
		git tag E3 &&

		git checkout C^0 &&
		test_must_fail git merge B^0 &&
		git clean -fd &&
		git rm -rf a/ &&
		git rm a &&
		test_write_lines 1 2 3 4 5 6 7 8 >a2 &&
		git add a2 &&
		git commit -m E4 &&
		git tag E4
	)
'

test_expect_success 'merge of D1 & E1 fails but has appropriate contents' '
	test_when_finished "git -C directory-file reset --hard" &&
	test_when_finished "git -C directory-file clean -fdqx" &&
	(
		cd directory-file &&

		git checkout D1^0 &&

		test_must_fail git merge -s recursive E1^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 1 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		git rev-parse >expect    \
			A:ignore-me  B:a &&
		git rev-parse   >actual   \
			:0:ignore-me :2:a &&
		test_cmp expect actual
	)
'

test_expect_success 'merge of E1 & D1 fails but has appropriate contents' '
	test_when_finished "git -C directory-file reset --hard" &&
	test_when_finished "git -C directory-file clean -fdqx" &&
	(
		cd directory-file &&

		git checkout E1^0 &&

		test_must_fail git merge -s recursive D1^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 1 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		git rev-parse >expect    \
			A:ignore-me  B:a &&
		git rev-parse   >actual   \
			:0:ignore-me :3:a &&
		test_cmp expect actual
	)
'

test_expect_success 'merge of D1 & E2 fails but has appropriate contents' '
	test_when_finished "git -C directory-file reset --hard" &&
	test_when_finished "git -C directory-file clean -fdqx" &&
	(
		cd directory-file &&

		git checkout D1^0 &&

		test_must_fail git merge -s recursive E2^0 &&

		git ls-files -s >out &&
		test_line_count = 4 out &&
		git ls-files -u >out &&
		test_line_count = 3 out &&
		git ls-files -o >out &&
		test_line_count = 2 out &&

		git rev-parse >expect    \
			B:a   E2:a/file  C:a/file   A:ignore-me &&
		git rev-parse   >actual   \
			:2:a  :3:a/file  :1:a/file  :0:ignore-me &&
		test_cmp expect actual &&

		test_path_is_file a~HEAD
	)
'

test_expect_success 'merge of E2 & D1 fails but has appropriate contents' '
	test_when_finished "git -C directory-file reset --hard" &&
	test_when_finished "git -C directory-file clean -fdqx" &&
	(
		cd directory-file &&

		git checkout E2^0 &&

		test_must_fail git merge -s recursive D1^0 &&

		git ls-files -s >out &&
		test_line_count = 4 out &&
		git ls-files -u >out &&
		test_line_count = 3 out &&
		git ls-files -o >out &&
		test_line_count = 2 out &&

		git rev-parse >expect    \
			B:a   E2:a/file  C:a/file   A:ignore-me &&
		git rev-parse   >actual   \
			:3:a  :2:a/file  :1:a/file  :0:ignore-me &&
		test_cmp expect actual &&

		test_path_is_file a~D1^0
	)
'

test_expect_success 'merge of D1 & E3 succeeds' '
	test_when_finished "git -C directory-file reset --hard" &&
	test_when_finished "git -C directory-file clean -fdqx" &&
	(
		cd directory-file &&

		git checkout D1^0 &&

		git merge -s recursive E3^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 0 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		git rev-parse >expect    \
			A:ignore-me  E3:a &&
		git rev-parse   >actual   \
			:0:ignore-me :0:a &&
		test_cmp expect actual
	)
'

test_expect_success 'merge of D1 & E4 notifies user a and a2 are related' '
	test_when_finished "git -C directory-file reset --hard" &&
	test_when_finished "git -C directory-file clean -fdqx" &&
	(
		cd directory-file &&

		git checkout D1^0 &&

		test_must_fail git merge -s recursive E4^0 &&

		git ls-files -s >out &&
		test_line_count = 4 out &&
		git ls-files -u >out &&
		test_line_count = 3 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		git rev-parse >expect                  \
			A:ignore-me  B:a   D1:a  E4:a2 &&
		git rev-parse   >actual                \
			:0:ignore-me :1:a~Temporary\ merge\ branch\ 2  :2:a  :3:a2 &&
		test_cmp expect actual
	)
'

test_expect_failure 'merge of D2 & E4 merges a2s & reports conflict for a/file' '
	test_when_finished "git -C directory-file reset --hard" &&
	test_when_finished "git -C directory-file clean -fdqx" &&
	(
		cd directory-file &&

		git checkout D2^0 &&

		test_must_fail git merge -s recursive E4^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 1 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		git rev-parse >expect                 \
			A:ignore-me  E4:a2  D2:a/file &&
		git rev-parse   >actual               \
			:0:ignore-me :0:a2  :2:a/file &&
		test_cmp expect actual
	)
'

#
# criss-cross with rename/rename(1to2)/modify followed by
# rename/rename(2to1)/modify:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: new file: a
#   Commit B: rename a->b, modifying by adding a line
#   Commit C: rename a->c
#   Commit D: merge B&C, resolving conflict by keeping contents in newname
#   Commit E: merge B&C, resolving conflict similar to D but adding another line
#
# There is a conflict merging B & C, but one of filename not of file
# content.  Whoever created D and E chose specific resolutions for that
# conflict resolution.  Now, since: (1) there is no content conflict
# merging B & C, (2) D does not modify that merged content further, and (3)
# both D & E resolve the name conflict in the same way, the modification to
# newname in E should not cause any conflicts when it is merged with D.
# (Note that this can be accomplished by having the virtual merge base have
# the merged contents of b and c stored in a file named a, which seems like
# the most logical choice anyway.)
#
# Comment from Junio: I do not necessarily agree with the choice "a", but
# it feels sound to say "B and C do not agree what the final pathname
# should be, but we know this content was derived from the common A:a so we
# use one path whose name is arbitrary in the virtual merge base X between
# D and E" and then further let the rename detection to notice that that
# arbitrary path gets renamed between X-D to "newname" and X-E also to
# "newname" to resolve it as both sides renaming it to the same new
# name. It is akin to what we do at the content level, i.e. "B and C do not
# agree what the final contents should be, so we leave the conflict marker
# but that may cancel out at the final merge stage".

test_expect_success 'setup rename/rename(1to2)/modify followed by what looks like rename/rename(2to1)/modify' '
	test_create_repo rename-squared-squared &&
	(
		cd rename-squared-squared &&

		printf "1\n2\n3\n4\n5\n6\n" >a &&
		git add a &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		git mv a b &&
		echo 7 >>b &&
		git add -u &&
		git commit -m B &&

		git checkout -b C A &&
		git mv a c &&
		git commit -m C &&

		git checkout -q B^0 &&
		git merge --no-commit -s ours C^0 &&
		git mv b newname &&
		git commit -m "Merge commit C^0 into HEAD" &&
		git tag D &&

		git checkout -q C^0 &&
		git merge --no-commit -s ours B^0 &&
		git mv c newname &&
		printf "7\n8\n" >>newname &&
		git add -u &&
		git commit -m "Merge commit B^0 into HEAD" &&
		git tag E
	)
'

test_expect_success 'handle rename/rename(1to2)/modify followed by what looks like rename/rename(2to1)/modify' '
	(
		cd rename-squared-squared &&

		git checkout D^0 &&

		git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 1 out &&
		git ls-files -u >out &&
		test_line_count = 0 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		test $(git rev-parse HEAD:newname) = $(git rev-parse E:newname)
	)
'

#
# criss-cross with rename/rename(1to2)/add-source + resolvable modify/modify:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: new file: a
#   Commit B: rename a->b
#   Commit C: rename a->c, add different a
#   Commit D: merge B&C, keeping b&c and (new) a modified at beginning
#   Commit E: merge B&C, keeping b&c and (new) a modified at end
#
# Merging commits D & E should result in no conflict; doing so correctly
# requires getting the virtual merge base (from merging B&C) right, handling
# renaming carefully (both in the virtual merge base and later), and getting
# content merge handled.

test_expect_success 'setup criss-cross + rename/rename/add-source + modify/modify' '
	test_create_repo rename-rename-add-source &&
	(
		cd rename-rename-add-source &&

		printf "lots\nof\nwords\nand\ncontent\n" >a &&
		git add a &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		git mv a b &&
		git commit -m B &&

		git checkout -b C A &&
		git mv a c &&
		printf "2\n3\n4\n5\n6\n7\n" >a &&
		git add a &&
		git commit -m C &&

		git checkout B^0 &&
		git merge --no-commit -s ours C^0 &&
		git checkout C -- a c &&
		mv a old_a &&
		echo 1 >a &&
		cat old_a >>a &&
		rm old_a &&
		git add -u &&
		git commit -m "Merge commit C^0 into HEAD" &&
		git tag D &&

		git checkout C^0 &&
		git merge --no-commit -s ours B^0 &&
		git checkout B -- b &&
		echo 8 >>a &&
		git add -u &&
		git commit -m "Merge commit B^0 into HEAD" &&
		git tag E
	)
'

test_expect_failure 'detect rename/rename/add-source for virtual merge-base' '
	(
		cd rename-rename-add-source &&

		git checkout D^0 &&

		git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 0 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		printf "1\n2\n3\n4\n5\n6\n7\n8\n" >correct &&
		git rev-parse >expect \
			A:a   A:a     \
			correct       &&
		git rev-parse   >actual  \
			:0:b  :0:c       &&
		git hash-object >>actual \
			a                &&
		test_cmp expect actual
	)
'

#
# criss-cross with rename/rename(1to2)/add-dest + simple modify:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: new file: a
#   Commit B: rename a->b, add c
#   Commit C: rename a->c
#   Commit D: merge B&C, keeping A:a and B:c
#   Commit E: merge B&C, keeping A:a and slightly modified c from B
#
# Merging commits D & E should result in no conflict.  The virtual merge
# base of B & C needs to not delete B:c for that to work, though...

test_expect_success 'setup criss-cross+rename/rename/add-dest + simple modify' '
	test_create_repo rename-rename-add-dest &&
	(
		cd rename-rename-add-dest &&

		>a &&
		git add a &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		git mv a b &&
		printf "1\n2\n3\n4\n5\n6\n7\n" >c &&
		git add c &&
		git commit -m B &&

		git checkout -b C A &&
		git mv a c &&
		git commit -m C &&

		git checkout B^0 &&
		git merge --no-commit -s ours C^0 &&
		git mv b a &&
		git commit -m "D is like B but renames b back to a" &&
		git tag D &&

		git checkout B^0 &&
		git merge --no-commit -s ours C^0 &&
		git mv b a &&
		echo 8 >>c &&
		git add c &&
		git commit -m "E like D but has mod in c" &&
		git tag E
	)
'

test_expect_success 'virtual merge base handles rename/rename(1to2)/add-dest' '
	(
		cd rename-rename-add-dest &&

		git checkout D^0 &&

		git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 0 out &&
		git ls-files -o >out &&
		test_line_count = 1 out &&

		git rev-parse >expect \
			A:a   E:c     &&
		git rev-parse   >actual \
			:0:a  :0:c      &&
		test_cmp expect actual
	)
'

#
# criss-cross with modify/modify on a symlink:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: simple simlink fickle->lagoon
#   Commit B: redirect fickle->disneyland
#   Commit C: redirect fickle->home
#   Commit D: merge B&C, resolving in favor of B
#   Commit E: merge B&C, resolving in favor of C
#
# This is an obvious modify/modify conflict for the symlink 'fickle'.  Can
# git detect it?

test_expect_success 'setup symlink modify/modify' '
	test_create_repo symlink-modify-modify &&
	(
		cd symlink-modify-modify &&

		test_ln_s_add lagoon fickle &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		git rm fickle &&
		test_ln_s_add disneyland fickle &&
		git commit -m B &&

		git checkout -b C A &&
		git rm fickle &&
		test_ln_s_add home fickle &&
		git add fickle &&
		git commit -m C &&

		git checkout -q B^0 &&
		git merge -s ours -m D C^0 &&
		git tag D &&

		git checkout -q C^0 &&
		git merge -s ours -m E B^0 &&
		git tag E
	)
'

test_expect_failure 'check symlink modify/modify' '
	(
		cd symlink-modify-modify &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 3 out &&
		git ls-files -o >out &&
		test_line_count = 1 out
	)
'

#
# criss-cross with add/add of a symlink:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: No symlink or path exists yet
#   Commit B: set up symlink: fickle->disneyland
#   Commit C: set up symlink: fickle->home
#   Commit D: merge B&C, resolving in favor of B
#   Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add conflict for the symlink 'fickle'.  Can
# git detect it?

test_expect_success 'setup symlink add/add' '
	test_create_repo symlink-add-add &&
	(
		cd symlink-add-add &&

		touch ignoreme &&
		git add ignoreme &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		test_ln_s_add disneyland fickle &&
		git commit -m B &&

		git checkout -b C A &&
		test_ln_s_add home fickle &&
		git add fickle &&
		git commit -m C &&

		git checkout -q B^0 &&
		git merge -s ours -m D C^0 &&
		git tag D &&

		git checkout -q C^0 &&
		git merge -s ours -m E B^0 &&
		git tag E
	)
'

test_expect_failure 'check symlink add/add' '
	(
		cd symlink-add-add &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 2 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&
		git ls-files -o >out &&
		test_line_count = 1 out
	)
'

#
# criss-cross with modify/modify on a submodule:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: simple submodule repo
#   Commit B: update repo
#   Commit C: update repo differently
#   Commit D: merge B&C, resolving in favor of B
#   Commit E: merge B&C, resolving in favor of C
#
# This is an obvious modify/modify conflict for the submodule 'repo'.  Can
# git detect it?

test_expect_success 'setup submodule modify/modify' '
	test_create_repo submodule-modify-modify &&
	(
		cd submodule-modify-modify &&

		test_create_repo submod &&
		(
			cd submod &&
			touch file-A &&
			git add file-A &&
			git commit -m A &&
			git tag A &&

			git checkout -b B A &&
			touch file-B &&
			git add file-B &&
			git commit -m B &&
			git tag B &&

			git checkout -b C A &&
			touch file-C &&
			git add file-C &&
			git commit -m C &&
			git tag C
		) &&

		git -C submod reset --hard A &&
		git add submod &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		git -C submod reset --hard B &&
		git add submod &&
		git commit -m B &&

		git checkout -b C A &&
		git -C submod reset --hard C &&
		git add submod &&
		git commit -m C &&

		git checkout -q B^0 &&
		git merge -s ours -m D C^0 &&
		git tag D &&

		git checkout -q C^0 &&
		git merge -s ours -m E B^0 &&
		git tag E
	)
'

test_expect_failure 'check submodule modify/modify' '
	(
		cd submodule-modify-modify &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 3 out &&
		git ls-files -o >out &&
		test_line_count = 1 out
	)
'

#
# criss-cross with add/add on a submodule:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: nothing of note
#   Commit B: introduce submodule repo
#   Commit C: introduce submodule repo at different commit
#   Commit D: merge B&C, resolving in favor of B
#   Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add conflict for the submodule 'repo'.  Can
# git detect it?

test_expect_success 'setup submodule add/add' '
	test_create_repo submodule-add-add &&
	(
		cd submodule-add-add &&

		test_create_repo submod &&
		(
			cd submod &&
			touch file-A &&
			git add file-A &&
			git commit -m A &&
			git tag A &&

			git checkout -b B A &&
			touch file-B &&
			git add file-B &&
			git commit -m B &&
			git tag B &&

			git checkout -b C A &&
			touch file-C &&
			git add file-C &&
			git commit -m C &&
			git tag C
		) &&

		touch irrelevant-file &&
		git add irrelevant-file &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		git -C submod reset --hard B &&
		git add submod &&
		git commit -m B &&

		git checkout -b C A &&
		git -C submod reset --hard C &&
		git add submod &&
		git commit -m C &&

		git checkout -q B^0 &&
		git merge -s ours -m D C^0 &&
		git tag D &&

		git checkout -q C^0 &&
		git merge -s ours -m E B^0 &&
		git tag E
	)
'

test_expect_failure 'check submodule add/add' '
	(
		cd submodule-add-add &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&
		git ls-files -o >out &&
		test_line_count = 1 out
	)
'

#
# criss-cross with conflicting entry types:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: nothing of note
#   Commit B: introduce submodule 'path'
#   Commit C: introduce symlink 'path'
#   Commit D: merge B&C, resolving in favor of B
#   Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add conflict for 'path'.  Can git detect it?

test_expect_success 'setup conflicting entry types (submodule vs symlink)' '
	test_create_repo submodule-symlink-add-add &&
	(
		cd submodule-symlink-add-add &&

		test_create_repo path &&
		(
			cd path &&
			touch file-B &&
			git add file-B &&
			git commit -m B &&
			git tag B
		) &&

		touch irrelevant-file &&
		git add irrelevant-file &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		git -C path reset --hard B &&
		git add path &&
		git commit -m B &&

		git checkout -b C A &&
		rm -rf path/ &&
		test_ln_s_add irrelevant-file path &&
		git commit -m C &&

		git checkout -q B^0 &&
		git merge -s ours -m D C^0 &&
		git tag D &&

		git checkout -q C^0 &&
		git merge -s ours -m E B^0 &&
		git tag E
	)
'

test_expect_failure 'check conflicting entry types (submodule vs symlink)' '
	(
		cd submodule-symlink-add-add &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&
		git ls-files -o >out &&
		test_line_count = 1 out
	)
'

#
# criss-cross with regular files that have conflicting modes:
#
#      B   D
#      o---o
#     / \ / \
#  A o   X   ? F
#     \ / \ /
#      o---o
#      C   E
#
#   Commit A: nothing of note
#   Commit B: introduce file source_me.bash, not executable
#   Commit C: introduce file source_me.bash, executable
#   Commit D: merge B&C, resolving in favor of B
#   Commit E: merge B&C, resolving in favor of C
#
# This is an obvious add/add mode conflict.  Can git detect it?

test_expect_success 'setup conflicting modes for regular file' '
	test_create_repo regular-file-mode-conflict &&
	(
		cd regular-file-mode-conflict &&

		touch irrelevant-file &&
		git add irrelevant-file &&
		git commit -m A &&
		git tag A &&

		git checkout -b B A &&
		echo "command_to_run" >source_me.bash &&
		git add source_me.bash &&
		git commit -m B &&

		git checkout -b C A &&
		echo "command_to_run" >source_me.bash &&
		git add source_me.bash &&
		test_chmod +x source_me.bash &&
		git commit -m C &&

		git checkout -q B^0 &&
		git merge -s ours -m D C^0 &&
		git tag D &&

		git checkout -q C^0 &&
		git merge -s ours -m E B^0 &&
		git tag E
	)
'

test_expect_failure 'check conflicting modes for regular file' '
	(
		cd regular-file-mode-conflict &&

		git checkout D^0 &&

		test_must_fail git merge -s recursive E^0 &&

		git ls-files -s >out &&
		test_line_count = 3 out &&
		git ls-files -u >out &&
		test_line_count = 2 out &&
		git ls-files -o >out &&
		test_line_count = 1 out
	)
'

test_done