File: histedit.py

package info (click to toggle)
mercurial 4.0-1%2Bdeb9u1
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 32,100 kB
  • ctags: 13,376
  • sloc: python: 94,424; ansic: 8,392; tcl: 3,715; lisp: 1,448; sh: 999; makefile: 375; xml: 35
file content (1604 lines) | stat: -rw-r--r-- 57,261 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
# histedit.py - interactive history editing for mercurial
#
# Copyright 2009 Augie Fackler <raf@durin42.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""interactive history editing

With this extension installed, Mercurial gains one new command: histedit. Usage
is as follows, assuming the following history::

 @  3[tip]   7c2fd3b9020c   2009-04-27 18:04 -0500   durin42
 |    Add delta
 |
 o  2   030b686bedc4   2009-04-27 18:04 -0500   durin42
 |    Add gamma
 |
 o  1   c561b4e977df   2009-04-27 18:04 -0500   durin42
 |    Add beta
 |
 o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
      Add alpha

If you were to run ``hg histedit c561b4e977df``, you would see the following
file open in your editor::

 pick c561b4e977df Add beta
 pick 030b686bedc4 Add gamma
 pick 7c2fd3b9020c Add delta

 # Edit history between c561b4e977df and 7c2fd3b9020c
 #
 # Commits are listed from least to most recent
 #
 # Commands:
 #  p, pick = use commit
 #  e, edit = use commit, but stop for amending
 #  f, fold = use commit, but combine it with the one above
 #  r, roll = like fold, but discard this commit's description
 #  d, drop = remove commit from history
 #  m, mess = edit commit message without changing commit content
 #

In this file, lines beginning with ``#`` are ignored. You must specify a rule
for each revision in your history. For example, if you had meant to add gamma
before beta, and then wanted to add delta in the same revision as beta, you
would reorganize the file to look like this::

 pick 030b686bedc4 Add gamma
 pick c561b4e977df Add beta
 fold 7c2fd3b9020c Add delta

 # Edit history between c561b4e977df and 7c2fd3b9020c
 #
 # Commits are listed from least to most recent
 #
 # Commands:
 #  p, pick = use commit
 #  e, edit = use commit, but stop for amending
 #  f, fold = use commit, but combine it with the one above
 #  r, roll = like fold, but discard this commit's description
 #  d, drop = remove commit from history
 #  m, mess = edit commit message without changing commit content
 #

At which point you close the editor and ``histedit`` starts working. When you
specify a ``fold`` operation, ``histedit`` will open an editor when it folds
those revisions together, offering you a chance to clean up the commit message::

 Add beta
 ***
 Add delta

Edit the commit message to your liking, then close the editor. For
this example, let's assume that the commit message was changed to
``Add beta and delta.`` After histedit has run and had a chance to
remove any old or temporary revisions it needed, the history looks
like this::

 @  2[tip]   989b4d060121   2009-04-27 18:04 -0500   durin42
 |    Add beta and delta.
 |
 o  1   081603921c3f   2009-04-27 18:04 -0500   durin42
 |    Add gamma
 |
 o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
      Add alpha

Note that ``histedit`` does *not* remove any revisions (even its own temporary
ones) until after it has completed all the editing operations, so it will
probably perform several strip operations when it's done. For the above example,
it had to run strip twice. Strip can be slow depending on a variety of factors,
so you might need to be a little patient. You can choose to keep the original
revisions by passing the ``--keep`` flag.

The ``edit`` operation will drop you back to a command prompt,
allowing you to edit files freely, or even use ``hg record`` to commit
some changes as a separate commit. When you're done, any remaining
uncommitted changes will be committed as well. When done, run ``hg
histedit --continue`` to finish this step. You'll be prompted for a
new commit message, but the default commit message will be the
original message for the ``edit`` ed revision.

The ``message`` operation will give you a chance to revise a commit
message without changing the contents. It's a shortcut for doing
``edit`` immediately followed by `hg histedit --continue``.

If ``histedit`` encounters a conflict when moving a revision (while
handling ``pick`` or ``fold``), it'll stop in a similar manner to
``edit`` with the difference that it won't prompt you for a commit
message when done. If you decide at this point that you don't like how
much work it will be to rearrange history, or that you made a mistake,
you can use ``hg histedit --abort`` to abandon the new changes you
have made and return to the state before you attempted to edit your
history.

If we clone the histedit-ed example repository above and add four more
changes, such that we have the following history::

   @  6[tip]   038383181893   2009-04-27 18:04 -0500   stefan
   |    Add theta
   |
   o  5   140988835471   2009-04-27 18:04 -0500   stefan
   |    Add eta
   |
   o  4   122930637314   2009-04-27 18:04 -0500   stefan
   |    Add zeta
   |
   o  3   836302820282   2009-04-27 18:04 -0500   stefan
   |    Add epsilon
   |
   o  2   989b4d060121   2009-04-27 18:04 -0500   durin42
   |    Add beta and delta.
   |
   o  1   081603921c3f   2009-04-27 18:04 -0500   durin42
   |    Add gamma
   |
   o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
        Add alpha

If you run ``hg histedit --outgoing`` on the clone then it is the same
as running ``hg histedit 836302820282``. If you need plan to push to a
repository that Mercurial does not detect to be related to the source
repo, you can add a ``--force`` option.

Config
------

Histedit rule lines are truncated to 80 characters by default. You
can customize this behavior by setting a different length in your
configuration file::

  [histedit]
  linelen = 120      # truncate rule lines at 120 characters

``hg histedit`` attempts to automatically choose an appropriate base
revision to use. To change which base revision is used, define a
revset in your configuration file::

  [histedit]
  defaultrev = only(.) & draft()

By default each edited revision needs to be present in histedit commands.
To remove revision you need to use ``drop`` operation. You can configure
the drop to be implicit for missing commits by adding::

  [histedit]
  dropmissing = True

"""

from __future__ import absolute_import

import errno
import os
import sys

from mercurial.i18n import _
from mercurial import (
    bundle2,
    cmdutil,
    context,
    copies,
    destutil,
    discovery,
    error,
    exchange,
    extensions,
    hg,
    lock,
    merge as mergemod,
    node,
    obsolete,
    repair,
    scmutil,
    util,
)

pickle = util.pickle
release = lock.release
cmdtable = {}
command = cmdutil.command(cmdtable)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

actiontable = {}
primaryactions = set()
secondaryactions = set()
tertiaryactions = set()
internalactions = set()

def geteditcomment(ui, first, last):
    """ construct the editor comment
    The comment includes::
     - an intro
     - sorted primary commands
     - sorted short commands
     - sorted long commands
     - additional hints

    Commands are only included once.
    """
    intro = _("""Edit history between %s and %s

Commits are listed from least to most recent

You can reorder changesets by reordering the lines

Commands:
""")
    actions = []
    def addverb(v):
        a = actiontable[v]
        lines = a.message.split("\n")
        if len(a.verbs):
            v = ', '.join(sorted(a.verbs, key=lambda v: len(v)))
        actions.append(" %s = %s" % (v, lines[0]))
        actions.extend(['  %s' for l in lines[1:]])

    for v in (
         sorted(primaryactions) +
         sorted(secondaryactions) +
         sorted(tertiaryactions)
        ):
        addverb(v)
    actions.append('')

    hints = []
    if ui.configbool('histedit', 'dropmissing'):
        hints.append("Deleting a changeset from the list "
                     "will DISCARD it from the edited history!")

    lines = (intro % (first, last)).split('\n') + actions + hints

    return ''.join(['# %s\n' % l if l else '#\n' for l in lines])

class histeditstate(object):
    def __init__(self, repo, parentctxnode=None, actions=None, keep=None,
            topmost=None, replacements=None, lock=None, wlock=None):
        self.repo = repo
        self.actions = actions
        self.keep = keep
        self.topmost = topmost
        self.parentctxnode = parentctxnode
        self.lock = lock
        self.wlock = wlock
        self.backupfile = None
        if replacements is None:
            self.replacements = []
        else:
            self.replacements = replacements

    def read(self):
        """Load histedit state from disk and set fields appropriately."""
        try:
            state = self.repo.vfs.read('histedit-state')
        except IOError as err:
            if err.errno != errno.ENOENT:
                raise
            cmdutil.wrongtooltocontinue(self.repo, _('histedit'))

        if state.startswith('v1\n'):
            data = self._load()
            parentctxnode, rules, keep, topmost, replacements, backupfile = data
        else:
            data = pickle.loads(state)
            parentctxnode, rules, keep, topmost, replacements = data
            backupfile = None

        self.parentctxnode = parentctxnode
        rules = "\n".join(["%s %s" % (verb, rest) for [verb, rest] in rules])
        actions = parserules(rules, self)
        self.actions = actions
        self.keep = keep
        self.topmost = topmost
        self.replacements = replacements
        self.backupfile = backupfile

    def write(self):
        fp = self.repo.vfs('histedit-state', 'w')
        fp.write('v1\n')
        fp.write('%s\n' % node.hex(self.parentctxnode))
        fp.write('%s\n' % node.hex(self.topmost))
        fp.write('%s\n' % self.keep)
        fp.write('%d\n' % len(self.actions))
        for action in self.actions:
            fp.write('%s\n' % action.tostate())
        fp.write('%d\n' % len(self.replacements))
        for replacement in self.replacements:
            fp.write('%s%s\n' % (node.hex(replacement[0]), ''.join(node.hex(r)
                for r in replacement[1])))
        backupfile = self.backupfile
        if not backupfile:
            backupfile = ''
        fp.write('%s\n' % backupfile)
        fp.close()

    def _load(self):
        fp = self.repo.vfs('histedit-state', 'r')
        lines = [l[:-1] for l in fp.readlines()]

        index = 0
        lines[index] # version number
        index += 1

        parentctxnode = node.bin(lines[index])
        index += 1

        topmost = node.bin(lines[index])
        index += 1

        keep = lines[index] == 'True'
        index += 1

        # Rules
        rules = []
        rulelen = int(lines[index])
        index += 1
        for i in xrange(rulelen):
            ruleaction = lines[index]
            index += 1
            rule = lines[index]
            index += 1
            rules.append((ruleaction, rule))

        # Replacements
        replacements = []
        replacementlen = int(lines[index])
        index += 1
        for i in xrange(replacementlen):
            replacement = lines[index]
            original = node.bin(replacement[:40])
            succ = [node.bin(replacement[i:i + 40]) for i in
                    range(40, len(replacement), 40)]
            replacements.append((original, succ))
            index += 1

        backupfile = lines[index]
        index += 1

        fp.close()

        return parentctxnode, rules, keep, topmost, replacements, backupfile

    def clear(self):
        if self.inprogress():
            self.repo.vfs.unlink('histedit-state')

    def inprogress(self):
        return self.repo.vfs.exists('histedit-state')


class histeditaction(object):
    def __init__(self, state, node):
        self.state = state
        self.repo = state.repo
        self.node = node

    @classmethod
    def fromrule(cls, state, rule):
        """Parses the given rule, returning an instance of the histeditaction.
        """
        rulehash = rule.strip().split(' ', 1)[0]
        try:
            rev = node.bin(rulehash)
        except TypeError:
            raise error.ParseError("invalid changeset %s" % rulehash)
        return cls(state, rev)

    def verify(self, prev, expected, seen):
        """ Verifies semantic correctness of the rule"""
        repo = self.repo
        ha = node.hex(self.node)
        try:
            self.node = repo[ha].node()
        except error.RepoError:
            raise error.ParseError(_('unknown changeset %s listed')
                              % ha[:12])
        if self.node is not None:
            self._verifynodeconstraints(prev, expected, seen)

    def _verifynodeconstraints(self, prev, expected, seen):
        # by default command need a node in the edited list
        if self.node not in expected:
            raise error.ParseError(_('%s "%s" changeset was not a candidate')
                                   % (self.verb, node.short(self.node)),
                                   hint=_('only use listed changesets'))
        # and only one command per node
        if self.node in seen:
            raise error.ParseError(_('duplicated command for changeset %s') %
                                   node.short(self.node))

    def torule(self):
        """build a histedit rule line for an action

        by default lines are in the form:
        <hash> <rev> <summary>
        """
        ctx = self.repo[self.node]
        summary = _getsummary(ctx)
        line = '%s %s %d %s' % (self.verb, ctx, ctx.rev(), summary)
        # trim to 75 columns by default so it's not stupidly wide in my editor
        # (the 5 more are left for verb)
        maxlen = self.repo.ui.configint('histedit', 'linelen', default=80)
        maxlen = max(maxlen, 22) # avoid truncating hash
        return util.ellipsis(line, maxlen)

    def tostate(self):
        """Print an action in format used by histedit state files
           (the first line is a verb, the remainder is the second)
        """
        return "%s\n%s" % (self.verb, node.hex(self.node))

    def run(self):
        """Runs the action. The default behavior is simply apply the action's
        rulectx onto the current parentctx."""
        self.applychange()
        self.continuedirty()
        return self.continueclean()

    def applychange(self):
        """Applies the changes from this action's rulectx onto the current
        parentctx, but does not commit them."""
        repo = self.repo
        rulectx = repo[self.node]
        repo.ui.pushbuffer(error=True, labeled=True)
        hg.update(repo, self.state.parentctxnode, quietempty=True)
        stats = applychanges(repo.ui, repo, rulectx, {})
        if stats and stats[3] > 0:
            buf = repo.ui.popbuffer()
            repo.ui.write(*buf)
            raise error.InterventionRequired(
                _('Fix up the change (%s %s)') %
                (self.verb, node.short(self.node)),
                hint=_('hg histedit --continue to resume'))
        else:
            repo.ui.popbuffer()

    def continuedirty(self):
        """Continues the action when changes have been applied to the working
        copy. The default behavior is to commit the dirty changes."""
        repo = self.repo
        rulectx = repo[self.node]

        editor = self.commiteditor()
        commit = commitfuncfor(repo, rulectx)

        commit(text=rulectx.description(), user=rulectx.user(),
               date=rulectx.date(), extra=rulectx.extra(), editor=editor)

    def commiteditor(self):
        """The editor to be used to edit the commit message."""
        return False

    def continueclean(self):
        """Continues the action when the working copy is clean. The default
        behavior is to accept the current commit as the new version of the
        rulectx."""
        ctx = self.repo['.']
        if ctx.node() == self.state.parentctxnode:
            self.repo.ui.warn(_('%s: skipping changeset (no changes)\n') %
                              node.short(self.node))
            return ctx, [(self.node, tuple())]
        if ctx.node() == self.node:
            # Nothing changed
            return ctx, []
        return ctx, [(self.node, (ctx.node(),))]

def commitfuncfor(repo, src):
    """Build a commit function for the replacement of <src>

    This function ensure we apply the same treatment to all changesets.

    - Add a 'histedit_source' entry in extra.

    Note that fold has its own separated logic because its handling is a bit
    different and not easily factored out of the fold method.
    """
    phasemin = src.phase()
    def commitfunc(**kwargs):
        phasebackup = repo.ui.backupconfig('phases', 'new-commit')
        try:
            repo.ui.setconfig('phases', 'new-commit', phasemin,
                              'histedit')
            extra = kwargs.get('extra', {}).copy()
            extra['histedit_source'] = src.hex()
            kwargs['extra'] = extra
            return repo.commit(**kwargs)
        finally:
            repo.ui.restoreconfig(phasebackup)
    return commitfunc

def applychanges(ui, repo, ctx, opts):
    """Merge changeset from ctx (only) in the current working directory"""
    wcpar = repo.dirstate.parents()[0]
    if ctx.p1().node() == wcpar:
        # edits are "in place" we do not need to make any merge,
        # just applies changes on parent for editing
        cmdutil.revert(ui, repo, ctx, (wcpar, node.nullid), all=True)
        stats = None
    else:
        try:
            # ui.forcemerge is an internal variable, do not document
            repo.ui.setconfig('ui', 'forcemerge', opts.get('tool', ''),
                              'histedit')
            stats = mergemod.graft(repo, ctx, ctx.p1(), ['local', 'histedit'])
        finally:
            repo.ui.setconfig('ui', 'forcemerge', '', 'histedit')
    return stats

def collapse(repo, first, last, commitopts, skipprompt=False):
    """collapse the set of revisions from first to last as new one.

    Expected commit options are:
        - message
        - date
        - username
    Commit message is edited in all cases.

    This function works in memory."""
    ctxs = list(repo.set('%d::%d', first, last))
    if not ctxs:
        return None
    for c in ctxs:
        if not c.mutable():
            raise error.ParseError(
                _("cannot fold into public change %s") % node.short(c.node()))
    base = first.parents()[0]

    # commit a new version of the old changeset, including the update
    # collect all files which might be affected
    files = set()
    for ctx in ctxs:
        files.update(ctx.files())

    # Recompute copies (avoid recording a -> b -> a)
    copied = copies.pathcopies(base, last)

    # prune files which were reverted by the updates
    files = [f for f in files if not cmdutil.samefile(f, last, base)]
    # commit version of these files as defined by head
    headmf = last.manifest()
    def filectxfn(repo, ctx, path):
        if path in headmf:
            fctx = last[path]
            flags = fctx.flags()
            mctx = context.memfilectx(repo,
                                      fctx.path(), fctx.data(),
                                      islink='l' in flags,
                                      isexec='x' in flags,
                                      copied=copied.get(path))
            return mctx
        return None

    if commitopts.get('message'):
        message = commitopts['message']
    else:
        message = first.description()
    user = commitopts.get('user')
    date = commitopts.get('date')
    extra = commitopts.get('extra')

    parents = (first.p1().node(), first.p2().node())
    editor = None
    if not skipprompt:
        editor = cmdutil.getcommiteditor(edit=True, editform='histedit.fold')
    new = context.memctx(repo,
                         parents=parents,
                         text=message,
                         files=files,
                         filectxfn=filectxfn,
                         user=user,
                         date=date,
                         extra=extra,
                         editor=editor)
    return repo.commitctx(new)

def _isdirtywc(repo):
    return repo[None].dirty(missing=True)

def abortdirty():
    raise error.Abort(_('working copy has pending changes'),
        hint=_('amend, commit, or revert them and run histedit '
            '--continue, or abort with histedit --abort'))

def action(verbs, message, priority=False, internal=False):
    def wrap(cls):
        assert not priority or not internal
        verb = verbs[0]
        if priority:
            primaryactions.add(verb)
        elif internal:
            internalactions.add(verb)
        elif len(verbs) > 1:
            secondaryactions.add(verb)
        else:
            tertiaryactions.add(verb)

        cls.verb = verb
        cls.verbs = verbs
        cls.message = message
        for verb in verbs:
            actiontable[verb] = cls
        return cls
    return wrap

@action(['pick', 'p'],
        _('use commit'),
        priority=True)
class pick(histeditaction):
    def run(self):
        rulectx = self.repo[self.node]
        if rulectx.parents()[0].node() == self.state.parentctxnode:
            self.repo.ui.debug('node %s unchanged\n' % node.short(self.node))
            return rulectx, []

        return super(pick, self).run()

@action(['edit', 'e'],
        _('use commit, but stop for amending'),
        priority=True)
class edit(histeditaction):
    def run(self):
        repo = self.repo
        rulectx = repo[self.node]
        hg.update(repo, self.state.parentctxnode, quietempty=True)
        applychanges(repo.ui, repo, rulectx, {})
        raise error.InterventionRequired(
            _('Editing (%s), you may commit or record as needed now.')
            % node.short(self.node),
            hint=_('hg histedit --continue to resume'))

    def commiteditor(self):
        return cmdutil.getcommiteditor(edit=True, editform='histedit.edit')

@action(['fold', 'f'],
        _('use commit, but combine it with the one above'))
class fold(histeditaction):
    def verify(self, prev, expected, seen):
        """ Verifies semantic correctness of the fold rule"""
        super(fold, self).verify(prev, expected, seen)
        repo = self.repo
        if not prev:
            c = repo[self.node].parents()[0]
        elif not prev.verb in ('pick', 'base'):
            return
        else:
            c = repo[prev.node]
        if not c.mutable():
            raise error.ParseError(
                _("cannot fold into public change %s") % node.short(c.node()))


    def continuedirty(self):
        repo = self.repo
        rulectx = repo[self.node]

        commit = commitfuncfor(repo, rulectx)
        commit(text='fold-temp-revision %s' % node.short(self.node),
               user=rulectx.user(), date=rulectx.date(),
               extra=rulectx.extra())

    def continueclean(self):
        repo = self.repo
        ctx = repo['.']
        rulectx = repo[self.node]
        parentctxnode = self.state.parentctxnode
        if ctx.node() == parentctxnode:
            repo.ui.warn(_('%s: empty changeset\n') %
                              node.short(self.node))
            return ctx, [(self.node, (parentctxnode,))]

        parentctx = repo[parentctxnode]
        newcommits = set(c.node() for c in repo.set('(%d::. - %d)', parentctx,
                                                 parentctx))
        if not newcommits:
            repo.ui.warn(_('%s: cannot fold - working copy is not a '
                           'descendant of previous commit %s\n') %
                           (node.short(self.node), node.short(parentctxnode)))
            return ctx, [(self.node, (ctx.node(),))]

        middlecommits = newcommits.copy()
        middlecommits.discard(ctx.node())

        return self.finishfold(repo.ui, repo, parentctx, rulectx, ctx.node(),
                               middlecommits)

    def skipprompt(self):
        """Returns true if the rule should skip the message editor.

        For example, 'fold' wants to show an editor, but 'rollup'
        doesn't want to.
        """
        return False

    def mergedescs(self):
        """Returns true if the rule should merge messages of multiple changes.

        This exists mainly so that 'rollup' rules can be a subclass of
        'fold'.
        """
        return True

    def finishfold(self, ui, repo, ctx, oldctx, newnode, internalchanges):
        parent = ctx.parents()[0].node()
        repo.ui.pushbuffer()
        hg.update(repo, parent)
        repo.ui.popbuffer()
        ### prepare new commit data
        commitopts = {}
        commitopts['user'] = ctx.user()
        # commit message
        if not self.mergedescs():
            newmessage = ctx.description()
        else:
            newmessage = '\n***\n'.join(
                [ctx.description()] +
                [repo[r].description() for r in internalchanges] +
                [oldctx.description()]) + '\n'
        commitopts['message'] = newmessage
        # date
        commitopts['date'] = max(ctx.date(), oldctx.date())
        extra = ctx.extra().copy()
        # histedit_source
        # note: ctx is likely a temporary commit but that the best we can do
        #       here. This is sufficient to solve issue3681 anyway.
        extra['histedit_source'] = '%s,%s' % (ctx.hex(), oldctx.hex())
        commitopts['extra'] = extra
        phasebackup = repo.ui.backupconfig('phases', 'new-commit')
        try:
            phasemin = max(ctx.phase(), oldctx.phase())
            repo.ui.setconfig('phases', 'new-commit', phasemin, 'histedit')
            n = collapse(repo, ctx, repo[newnode], commitopts,
                         skipprompt=self.skipprompt())
        finally:
            repo.ui.restoreconfig(phasebackup)
        if n is None:
            return ctx, []
        repo.ui.pushbuffer()
        hg.update(repo, n)
        repo.ui.popbuffer()
        replacements = [(oldctx.node(), (newnode,)),
                        (ctx.node(), (n,)),
                        (newnode, (n,)),
                       ]
        for ich in internalchanges:
            replacements.append((ich, (n,)))
        return repo[n], replacements

class base(histeditaction):

    def run(self):
        if self.repo['.'].node() != self.node:
            mergemod.update(self.repo, self.node, False, True)
            #                                     branchmerge, force)
        return self.continueclean()

    def continuedirty(self):
        abortdirty()

    def continueclean(self):
        basectx = self.repo['.']
        return basectx, []

    def _verifynodeconstraints(self, prev, expected, seen):
        # base can only be use with a node not in the edited set
        if self.node in expected:
            msg = _('%s "%s" changeset was an edited list candidate')
            raise error.ParseError(
                msg % (self.verb, node.short(self.node)),
                hint=_('base must only use unlisted changesets'))

@action(['_multifold'],
        _(
    """fold subclass used for when multiple folds happen in a row

    We only want to fire the editor for the folded message once when
    (say) four changes are folded down into a single change. This is
    similar to rollup, but we should preserve both messages so that
    when the last fold operation runs we can show the user all the
    commit messages in their editor.
    """),
        internal=True)
class _multifold(fold):
    def skipprompt(self):
        return True

@action(["roll", "r"],
        _("like fold, but discard this commit's description"))
class rollup(fold):
    def mergedescs(self):
        return False

    def skipprompt(self):
        return True

@action(["drop", "d"],
        _('remove commit from history'))
class drop(histeditaction):
    def run(self):
        parentctx = self.repo[self.state.parentctxnode]
        return parentctx, [(self.node, tuple())]

@action(["mess", "m"],
        _('edit commit message without changing commit content'),
        priority=True)
class message(histeditaction):
    def commiteditor(self):
        return cmdutil.getcommiteditor(edit=True, editform='histedit.mess')

def findoutgoing(ui, repo, remote=None, force=False, opts=None):
    """utility function to find the first outgoing changeset

    Used by initialization code"""
    if opts is None:
        opts = {}
    dest = ui.expandpath(remote or 'default-push', remote or 'default')
    dest, revs = hg.parseurl(dest, None)[:2]
    ui.status(_('comparing with %s\n') % util.hidepassword(dest))

    revs, checkout = hg.addbranchrevs(repo, repo, revs, None)
    other = hg.peer(repo, opts, dest)

    if revs:
        revs = [repo.lookup(rev) for rev in revs]

    outgoing = discovery.findcommonoutgoing(repo, other, revs, force=force)
    if not outgoing.missing:
        raise error.Abort(_('no outgoing ancestors'))
    roots = list(repo.revs("roots(%ln)", outgoing.missing))
    if 1 < len(roots):
        msg = _('there are ambiguous outgoing revisions')
        hint = _("see 'hg help histedit' for more detail")
        raise error.Abort(msg, hint=hint)
    return repo.lookup(roots[0])


@command('histedit',
    [('', 'commands', '',
      _('read history edits from the specified file'), _('FILE')),
     ('c', 'continue', False, _('continue an edit already in progress')),
     ('', 'edit-plan', False, _('edit remaining actions list')),
     ('k', 'keep', False,
      _("don't strip old nodes after edit is complete")),
     ('', 'abort', False, _('abort an edit in progress')),
     ('o', 'outgoing', False, _('changesets not found in destination')),
     ('f', 'force', False,
      _('force outgoing even for unrelated repositories')),
     ('r', 'rev', [], _('first revision to be edited'), _('REV'))],
     _("[OPTIONS] ([ANCESTOR] | --outgoing [URL])"))
def histedit(ui, repo, *freeargs, **opts):
    """interactively edit changeset history

    This command lets you edit a linear series of changesets (up to
    and including the working directory, which should be clean).
    You can:

    - `pick` to [re]order a changeset

    - `drop` to omit changeset

    - `mess` to reword the changeset commit message

    - `fold` to combine it with the preceding changeset

    - `roll` like fold, but discarding this commit's description

    - `edit` to edit this changeset

    There are a number of ways to select the root changeset:

    - Specify ANCESTOR directly

    - Use --outgoing -- it will be the first linear changeset not
      included in destination. (See :hg:`help config.paths.default-push`)

    - Otherwise, the value from the "histedit.defaultrev" config option
      is used as a revset to select the base revision when ANCESTOR is not
      specified. The first revision returned by the revset is used. By
      default, this selects the editable history that is unique to the
      ancestry of the working directory.

    .. container:: verbose

       If you use --outgoing, this command will abort if there are ambiguous
       outgoing revisions. For example, if there are multiple branches
       containing outgoing revisions.

       Use "min(outgoing() and ::.)" or similar revset specification
       instead of --outgoing to specify edit target revision exactly in
       such ambiguous situation. See :hg:`help revsets` for detail about
       selecting revisions.

    .. container:: verbose

       Examples:

         - A number of changes have been made.
           Revision 3 is no longer needed.

           Start history editing from revision 3::

             hg histedit -r 3

           An editor opens, containing the list of revisions,
           with specific actions specified::

             pick 5339bf82f0ca 3 Zworgle the foobar
             pick 8ef592ce7cc4 4 Bedazzle the zerlog
             pick 0a9639fcda9d 5 Morgify the cromulancy

           Additional information about the possible actions
           to take appears below the list of revisions.

           To remove revision 3 from the history,
           its action (at the beginning of the relevant line)
           is changed to 'drop'::

             drop 5339bf82f0ca 3 Zworgle the foobar
             pick 8ef592ce7cc4 4 Bedazzle the zerlog
             pick 0a9639fcda9d 5 Morgify the cromulancy

         - A number of changes have been made.
           Revision 2 and 4 need to be swapped.

           Start history editing from revision 2::

             hg histedit -r 2

           An editor opens, containing the list of revisions,
           with specific actions specified::

             pick 252a1af424ad 2 Blorb a morgwazzle
             pick 5339bf82f0ca 3 Zworgle the foobar
             pick 8ef592ce7cc4 4 Bedazzle the zerlog

           To swap revision 2 and 4, its lines are swapped
           in the editor::

             pick 8ef592ce7cc4 4 Bedazzle the zerlog
             pick 5339bf82f0ca 3 Zworgle the foobar
             pick 252a1af424ad 2 Blorb a morgwazzle

    Returns 0 on success, 1 if user intervention is required (not only
    for intentional "edit" command, but also for resolving unexpected
    conflicts).
    """
    state = histeditstate(repo)
    try:
        state.wlock = repo.wlock()
        state.lock = repo.lock()
        _histedit(ui, repo, state, *freeargs, **opts)
    finally:
        release(state.lock, state.wlock)

goalcontinue = 'continue'
goalabort = 'abort'
goaleditplan = 'edit-plan'
goalnew = 'new'

def _getgoal(opts):
    if opts.get('continue'):
        return goalcontinue
    if opts.get('abort'):
        return goalabort
    if opts.get('edit_plan'):
        return goaleditplan
    return goalnew

def _readfile(path):
    if path == '-':
        return sys.stdin.read()
    else:
        with open(path, 'rb') as f:
            return f.read()

def _validateargs(ui, repo, state, freeargs, opts, goal, rules, revs):
    # TODO only abort if we try to histedit mq patches, not just
    # blanket if mq patches are applied somewhere
    mq = getattr(repo, 'mq', None)
    if mq and mq.applied:
        raise error.Abort(_('source has mq patches applied'))

    # basic argument incompatibility processing
    outg = opts.get('outgoing')
    editplan = opts.get('edit_plan')
    abort = opts.get('abort')
    force = opts.get('force')
    if force and not outg:
        raise error.Abort(_('--force only allowed with --outgoing'))
    if goal == 'continue':
        if any((outg, abort, revs, freeargs, rules, editplan)):
            raise error.Abort(_('no arguments allowed with --continue'))
    elif goal == 'abort':
        if any((outg, revs, freeargs, rules, editplan)):
            raise error.Abort(_('no arguments allowed with --abort'))
    elif goal == 'edit-plan':
        if any((outg, revs, freeargs)):
            raise error.Abort(_('only --commands argument allowed with '
                               '--edit-plan'))
    else:
        if os.path.exists(os.path.join(repo.path, 'histedit-state')):
            raise error.Abort(_('history edit already in progress, try '
                               '--continue or --abort'))
        if outg:
            if revs:
                raise error.Abort(_('no revisions allowed with --outgoing'))
            if len(freeargs) > 1:
                raise error.Abort(
                    _('only one repo argument allowed with --outgoing'))
        else:
            revs.extend(freeargs)
            if len(revs) == 0:
                defaultrev = destutil.desthistedit(ui, repo)
                if defaultrev is not None:
                    revs.append(defaultrev)

            if len(revs) != 1:
                raise error.Abort(
                    _('histedit requires exactly one ancestor revision'))

def _histedit(ui, repo, state, *freeargs, **opts):
    goal = _getgoal(opts)
    revs = opts.get('rev', [])
    rules = opts.get('commands', '')
    state.keep = opts.get('keep', False)

    _validateargs(ui, repo, state, freeargs, opts, goal, rules, revs)

    # rebuild state
    if goal == goalcontinue:
        state.read()
        state = bootstrapcontinue(ui, state, opts)
    elif goal == goaleditplan:
        _edithisteditplan(ui, repo, state, rules)
        return
    elif goal == goalabort:
        _aborthistedit(ui, repo, state)
        return
    else:
        # goal == goalnew
        _newhistedit(ui, repo, state, revs, freeargs, opts)

    _continuehistedit(ui, repo, state)
    _finishhistedit(ui, repo, state)

def _continuehistedit(ui, repo, state):
    """This function runs after either:
    - bootstrapcontinue (if the goal is 'continue')
    - _newhistedit (if the goal is 'new')
    """
    # preprocess rules so that we can hide inner folds from the user
    # and only show one editor
    actions = state.actions[:]
    for idx, (action, nextact) in enumerate(
            zip(actions, actions[1:] + [None])):
        if action.verb == 'fold' and nextact and nextact.verb == 'fold':
            state.actions[idx].__class__ = _multifold

    total = len(state.actions)
    pos = 0
    while state.actions:
        state.write()
        actobj = state.actions.pop(0)
        pos += 1
        ui.progress(_("editing"), pos, actobj.torule(),
                    _('changes'), total)
        ui.debug('histedit: processing %s %s\n' % (actobj.verb,\
                                                   actobj.torule()))
        parentctx, replacement_ = actobj.run()
        state.parentctxnode = parentctx.node()
        state.replacements.extend(replacement_)
    state.write()
    ui.progress(_("editing"), None)

def _finishhistedit(ui, repo, state):
    """This action runs when histedit is finishing its session"""
    repo.ui.pushbuffer()
    hg.update(repo, state.parentctxnode, quietempty=True)
    repo.ui.popbuffer()

    mapping, tmpnodes, created, ntm = processreplacement(state)
    if mapping:
        for prec, succs in mapping.iteritems():
            if not succs:
                ui.debug('histedit: %s is dropped\n' % node.short(prec))
            else:
                ui.debug('histedit: %s is replaced by %s\n' % (
                    node.short(prec), node.short(succs[0])))
                if len(succs) > 1:
                    m = 'histedit:                            %s'
                    for n in succs[1:]:
                        ui.debug(m % node.short(n))

    supportsmarkers = obsolete.isenabled(repo, obsolete.createmarkersopt)
    if supportsmarkers:
        # Only create markers if the temp nodes weren't already removed.
        obsolete.createmarkers(repo, ((repo[t],()) for t in sorted(tmpnodes)
                                       if t in repo))
    else:
        cleanupnode(ui, repo, 'temp', tmpnodes)

    if not state.keep:
        if mapping:
            movebookmarks(ui, repo, mapping, state.topmost, ntm)
            # TODO update mq state
        if supportsmarkers:
            markers = []
            # sort by revision number because it sound "right"
            for prec in sorted(mapping, key=repo.changelog.rev):
                succs = mapping[prec]
                markers.append((repo[prec],
                                tuple(repo[s] for s in succs)))
            if markers:
                obsolete.createmarkers(repo, markers)
        else:
            cleanupnode(ui, repo, 'replaced', mapping)

    state.clear()
    if os.path.exists(repo.sjoin('undo')):
        os.unlink(repo.sjoin('undo'))
    if repo.vfs.exists('histedit-last-edit.txt'):
        repo.vfs.unlink('histedit-last-edit.txt')

def _aborthistedit(ui, repo, state):
    try:
        state.read()
        __, leafs, tmpnodes, __ = processreplacement(state)
        ui.debug('restore wc to old parent %s\n'
                % node.short(state.topmost))

        # Recover our old commits if necessary
        if not state.topmost in repo and state.backupfile:
            backupfile = repo.join(state.backupfile)
            f = hg.openpath(ui, backupfile)
            gen = exchange.readbundle(ui, f, backupfile)
            with repo.transaction('histedit.abort') as tr:
                if not isinstance(gen, bundle2.unbundle20):
                    gen.apply(repo, 'histedit', 'bundle:' + backupfile)
                if isinstance(gen, bundle2.unbundle20):
                    bundle2.applybundle(repo, gen, tr,
                                        source='histedit',
                                        url='bundle:' + backupfile)

            os.remove(backupfile)

        # check whether we should update away
        if repo.unfiltered().revs('parents() and (%n  or %ln::)',
                                state.parentctxnode, leafs | tmpnodes):
            hg.clean(repo, state.topmost, show_stats=True, quietempty=True)
        cleanupnode(ui, repo, 'created', tmpnodes)
        cleanupnode(ui, repo, 'temp', leafs)
    except Exception:
        if state.inprogress():
            ui.warn(_('warning: encountered an exception during histedit '
                '--abort; the repository may not have been completely '
                'cleaned up\n'))
        raise
    finally:
            state.clear()

def _edithisteditplan(ui, repo, state, rules):
    state.read()
    if not rules:
        comment = geteditcomment(ui,
                                 node.short(state.parentctxnode),
                                 node.short(state.topmost))
        rules = ruleeditor(repo, ui, state.actions, comment)
    else:
        rules = _readfile(rules)
    actions = parserules(rules, state)
    ctxs = [repo[act.node] \
            for act in state.actions if act.node]
    warnverifyactions(ui, repo, actions, state, ctxs)
    state.actions = actions
    state.write()

def _newhistedit(ui, repo, state, revs, freeargs, opts):
    outg = opts.get('outgoing')
    rules = opts.get('commands', '')
    force = opts.get('force')

    cmdutil.checkunfinished(repo)
    cmdutil.bailifchanged(repo)

    topmost, empty = repo.dirstate.parents()
    if outg:
        if freeargs:
            remote = freeargs[0]
        else:
            remote = None
        root = findoutgoing(ui, repo, remote, force, opts)
    else:
        rr = list(repo.set('roots(%ld)', scmutil.revrange(repo, revs)))
        if len(rr) != 1:
            raise error.Abort(_('The specified revisions must have '
                'exactly one common root'))
        root = rr[0].node()

    revs = between(repo, root, topmost, state.keep)
    if not revs:
        raise error.Abort(_('%s is not an ancestor of working directory') %
                         node.short(root))

    ctxs = [repo[r] for r in revs]
    if not rules:
        comment = geteditcomment(ui, node.short(root), node.short(topmost))
        actions = [pick(state, r) for r in revs]
        rules = ruleeditor(repo, ui, actions, comment)
    else:
        rules = _readfile(rules)
    actions = parserules(rules, state)
    warnverifyactions(ui, repo, actions, state, ctxs)

    parentctxnode = repo[root].parents()[0].node()

    state.parentctxnode = parentctxnode
    state.actions = actions
    state.topmost = topmost
    state.replacements = []

    # Create a backup so we can always abort completely.
    backupfile = None
    if not obsolete.isenabled(repo, obsolete.createmarkersopt):
        backupfile = repair._bundle(repo, [parentctxnode], [topmost], root,
                                    'histedit')
    state.backupfile = backupfile

def _getsummary(ctx):
    # a common pattern is to extract the summary but default to the empty
    # string
    summary = ctx.description() or ''
    if summary:
        summary = summary.splitlines()[0]
    return summary

def bootstrapcontinue(ui, state, opts):
    repo = state.repo
    if state.actions:
        actobj = state.actions.pop(0)

        if _isdirtywc(repo):
            actobj.continuedirty()
            if _isdirtywc(repo):
                abortdirty()

        parentctx, replacements = actobj.continueclean()

        state.parentctxnode = parentctx.node()
        state.replacements.extend(replacements)

    return state

def between(repo, old, new, keep):
    """select and validate the set of revision to edit

    When keep is false, the specified set can't have children."""
    ctxs = list(repo.set('%n::%n', old, new))
    if ctxs and not keep:
        if (not obsolete.isenabled(repo, obsolete.allowunstableopt) and
            repo.revs('(%ld::) - (%ld)', ctxs, ctxs)):
            raise error.Abort(_('can only histedit a changeset together '
                                'with all its descendants'))
        if repo.revs('(%ld) and merge()', ctxs):
            raise error.Abort(_('cannot edit history that contains merges'))
        root = ctxs[0] # list is already sorted by repo.set
        if not root.mutable():
            raise error.Abort(_('cannot edit public changeset: %s') % root,
                             hint=_("see 'hg help phases' for details"))
    return [c.node() for c in ctxs]

def ruleeditor(repo, ui, actions, editcomment=""):
    """open an editor to edit rules

    rules are in the format [ [act, ctx], ...] like in state.rules
    """
    if repo.ui.configbool("experimental", "histedit.autoverb"):
        newact = util.sortdict()
        for act in actions:
            ctx = repo[act.node]
            summary = _getsummary(ctx)
            fword = summary.split(' ', 1)[0].lower()
            added = False

            # if it doesn't end with the special character '!' just skip this
            if fword.endswith('!'):
                fword = fword[:-1]
                if fword in primaryactions | secondaryactions | tertiaryactions:
                    act.verb = fword
                    # get the target summary
                    tsum = summary[len(fword) + 1:].lstrip()
                    # safe but slow: reverse iterate over the actions so we
                    # don't clash on two commits having the same summary
                    for na, l in reversed(list(newact.iteritems())):
                        actx = repo[na.node]
                        asum = _getsummary(actx)
                        if asum == tsum:
                            added = True
                            l.append(act)
                            break

            if not added:
                newact[act] = []

        # copy over and flatten the new list
        actions = []
        for na, l in newact.iteritems():
            actions.append(na)
            actions += l

    rules = '\n'.join([act.torule() for act in actions])
    rules += '\n\n'
    rules += editcomment
    rules = ui.edit(rules, ui.username(), {'prefix': 'histedit'})

    # Save edit rules in .hg/histedit-last-edit.txt in case
    # the user needs to ask for help after something
    # surprising happens.
    f = open(repo.join('histedit-last-edit.txt'), 'w')
    f.write(rules)
    f.close()

    return rules

def parserules(rules, state):
    """Read the histedit rules string and return list of action objects """
    rules = [l for l in (r.strip() for r in rules.splitlines())
                if l and not l.startswith('#')]
    actions = []
    for r in rules:
        if ' ' not in r:
            raise error.ParseError(_('malformed line "%s"') % r)
        verb, rest = r.split(' ', 1)

        if verb not in actiontable:
            raise error.ParseError(_('unknown action "%s"') % verb)

        action = actiontable[verb].fromrule(state, rest)
        actions.append(action)
    return actions

def warnverifyactions(ui, repo, actions, state, ctxs):
    try:
        verifyactions(actions, state, ctxs)
    except error.ParseError:
        if repo.vfs.exists('histedit-last-edit.txt'):
            ui.warn(_('warning: histedit rules saved '
                      'to: .hg/histedit-last-edit.txt\n'))
        raise

def verifyactions(actions, state, ctxs):
    """Verify that there exists exactly one action per given changeset and
    other constraints.

    Will abort if there are to many or too few rules, a malformed rule,
    or a rule on a changeset outside of the user-given range.
    """
    expected = set(c.node() for c in ctxs)
    seen = set()
    prev = None
    for action in actions:
        action.verify(prev, expected, seen)
        prev = action
        if action.node is not None:
            seen.add(action.node)
    missing = sorted(expected - seen)  # sort to stabilize output

    if state.repo.ui.configbool('histedit', 'dropmissing'):
        if len(actions) == 0:
            raise error.ParseError(_('no rules provided'),
                    hint=_('use strip extension to remove commits'))

        drops = [drop(state, n) for n in missing]
        # put the in the beginning so they execute immediately and
        # don't show in the edit-plan in the future
        actions[:0] = drops
    elif missing:
        raise error.ParseError(_('missing rules for changeset %s') %
                node.short(missing[0]),
                hint=_('use "drop %s" to discard, see also: '
                       "'hg help -e histedit.config'")
                       % node.short(missing[0]))

def adjustreplacementsfrommarkers(repo, oldreplacements):
    """Adjust replacements from obsolescense markers

    Replacements structure is originally generated based on
    histedit's state and does not account for changes that are
    not recorded there. This function fixes that by adding
    data read from obsolescense markers"""
    if not obsolete.isenabled(repo, obsolete.createmarkersopt):
        return oldreplacements

    unfi = repo.unfiltered()
    nm = unfi.changelog.nodemap
    obsstore = repo.obsstore
    newreplacements = list(oldreplacements)
    oldsuccs = [r[1] for r in oldreplacements]
    # successors that have already been added to succstocheck once
    seensuccs = set().union(*oldsuccs) # create a set from an iterable of tuples
    succstocheck = list(seensuccs)
    while succstocheck:
        n = succstocheck.pop()
        missing = nm.get(n) is None
        markers = obsstore.successors.get(n, ())
        if missing and not markers:
            # dead end, mark it as such
            newreplacements.append((n, ()))
        for marker in markers:
            nsuccs = marker[1]
            newreplacements.append((n, nsuccs))
            for nsucc in nsuccs:
                if nsucc not in seensuccs:
                    seensuccs.add(nsucc)
                    succstocheck.append(nsucc)

    return newreplacements

def processreplacement(state):
    """process the list of replacements to return

    1) the final mapping between original and created nodes
    2) the list of temporary node created by histedit
    3) the list of new commit created by histedit"""
    replacements = adjustreplacementsfrommarkers(state.repo, state.replacements)
    allsuccs = set()
    replaced = set()
    fullmapping = {}
    # initialize basic set
    # fullmapping records all operations recorded in replacement
    for rep in replacements:
        allsuccs.update(rep[1])
        replaced.add(rep[0])
        fullmapping.setdefault(rep[0], set()).update(rep[1])
    new = allsuccs - replaced
    tmpnodes = allsuccs & replaced
    # Reduce content fullmapping into direct relation between original nodes
    # and final node created during history edition
    # Dropped changeset are replaced by an empty list
    toproceed = set(fullmapping)
    final = {}
    while toproceed:
        for x in list(toproceed):
            succs = fullmapping[x]
            for s in list(succs):
                if s in toproceed:
                    # non final node with unknown closure
                    # We can't process this now
                    break
                elif s in final:
                    # non final node, replace with closure
                    succs.remove(s)
                    succs.update(final[s])
            else:
                final[x] = succs
                toproceed.remove(x)
    # remove tmpnodes from final mapping
    for n in tmpnodes:
        del final[n]
    # we expect all changes involved in final to exist in the repo
    # turn `final` into list (topologically sorted)
    nm = state.repo.changelog.nodemap
    for prec, succs in final.items():
        final[prec] = sorted(succs, key=nm.get)

    # computed topmost element (necessary for bookmark)
    if new:
        newtopmost = sorted(new, key=state.repo.changelog.rev)[-1]
    elif not final:
        # Nothing rewritten at all. we won't need `newtopmost`
        # It is the same as `oldtopmost` and `processreplacement` know it
        newtopmost = None
    else:
        # every body died. The newtopmost is the parent of the root.
        r = state.repo.changelog.rev
        newtopmost = state.repo[sorted(final, key=r)[0]].p1().node()

    return final, tmpnodes, new, newtopmost

def movebookmarks(ui, repo, mapping, oldtopmost, newtopmost):
    """Move bookmark from old to newly created node"""
    if not mapping:
        # if nothing got rewritten there is not purpose for this function
        return
    moves = []
    for bk, old in sorted(repo._bookmarks.iteritems()):
        if old == oldtopmost:
            # special case ensure bookmark stay on tip.
            #
            # This is arguably a feature and we may only want that for the
            # active bookmark. But the behavior is kept compatible with the old
            # version for now.
            moves.append((bk, newtopmost))
            continue
        base = old
        new = mapping.get(base, None)
        if new is None:
            continue
        while not new:
            # base is killed, trying with parent
            base = repo[base].p1().node()
            new = mapping.get(base, (base,))
            # nothing to move
        moves.append((bk, new[-1]))
    if moves:
        lock = tr = None
        try:
            lock = repo.lock()
            tr = repo.transaction('histedit')
            marks = repo._bookmarks
            for mark, new in moves:
                old = marks[mark]
                ui.note(_('histedit: moving bookmarks %s from %s to %s\n')
                        % (mark, node.short(old), node.short(new)))
                marks[mark] = new
            marks.recordchange(tr)
            tr.close()
        finally:
            release(tr, lock)

def cleanupnode(ui, repo, name, nodes):
    """strip a group of nodes from the repository

    The set of node to strip may contains unknown nodes."""
    ui.debug('should strip %s nodes %s\n' %
             (name, ', '.join([node.short(n) for n in nodes])))
    with repo.lock():
        # do not let filtering get in the way of the cleanse
        # we should probably get rid of obsolescence marker created during the
        # histedit, but we currently do not have such information.
        repo = repo.unfiltered()
        # Find all nodes that need to be stripped
        # (we use %lr instead of %ln to silently ignore unknown items)
        nm = repo.changelog.nodemap
        nodes = sorted(n for n in nodes if n in nm)
        roots = [c.node() for c in repo.set("roots(%ln)", nodes)]
        for c in roots:
            # We should process node in reverse order to strip tip most first.
            # but this trigger a bug in changegroup hook.
            # This would reduce bundle overhead
            repair.strip(ui, repo, c)

def stripwrapper(orig, ui, repo, nodelist, *args, **kwargs):
    if isinstance(nodelist, str):
        nodelist = [nodelist]
    if os.path.exists(os.path.join(repo.path, 'histedit-state')):
        state = histeditstate(repo)
        state.read()
        histedit_nodes = set([action.node for action
                             in state.actions if action.node])
        common_nodes = histedit_nodes & set(nodelist)
        if common_nodes:
            raise error.Abort(_("histedit in progress, can't strip %s")
                             % ', '.join(node.short(x) for x in common_nodes))
    return orig(ui, repo, nodelist, *args, **kwargs)

extensions.wrapfunction(repair, 'strip', stripwrapper)

def summaryhook(ui, repo):
    if not os.path.exists(repo.join('histedit-state')):
        return
    state = histeditstate(repo)
    state.read()
    if state.actions:
        # i18n: column positioning for "hg summary"
        ui.write(_('hist:   %s (histedit --continue)\n') %
                 (ui.label(_('%d remaining'), 'histedit.remaining') %
                  len(state.actions)))

def extsetup(ui):
    cmdutil.summaryhooks.add('histedit', summaryhook)
    cmdutil.unfinishedstates.append(
        ['histedit-state', False, True, _('histedit in progress'),
         _("use 'hg histedit --continue' or 'hg histedit --abort'")])
    cmdutil.afterresolvedstates.append(
        ['histedit-state', _('hg histedit --continue')])
    if ui.configbool("experimental", "histeditng"):
        globals()['base'] = action(['base', 'b'],
            _('checkout changeset and apply further changesets from there')
        )(base)