histedit: add test that an invalid editor doesn't bork client state

We had a report of a situation like this borking a user at Google, but
I can't reproduce it in a test. Let's at least backstop the issue with
a test, so we don't accidentally introduce such a bug...

Differential Revision: https://phab.mercurial-scm.org/D8391

tests/test-histedit-non-commute.t

@@ -1,303 +1,306 b''
   $ . "$TESTDIR/histedit-helpers.sh"
 
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > histedit=
   > EOF
 
   $ initrepo ()
   > {
   >     hg init $1
   >     cd $1
   >     for x in a b c d e f ; do
   >         echo $x$x$x$x$x > $x
   >         hg add $x
   >     done
   >     hg ci -m 'Initial commit'
   >     for x in a b c d e f ; do
   >         echo $x > $x
   >         hg ci -m $x
   >     done
   >     echo 'I can haz no commute' > e
   >     hg ci -m 'does not commute with e'
   >     cd ..
   > }
 
   $ initrepo r1
   $ cd r1
 
 Initial generation of the command files
 
   $ EDITED="$TESTTMP/editedhistory"
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 7 >> $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
   $ cat $EDITED
   pick 65a9a84f33fd 3 c
   pick 00f1c5383965 4 d
   pick 39522b764e3d 7 does not commute with e
   pick 7b4e2f4b7bcd 5 e
   pick 500cac37a696 6 f
 
 log before edit
   $ hg log --graph
   @  changeset:   7:39522b764e3d
   |  tag:         tip
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     does not commute with e
   |
   o  changeset:   6:500cac37a696
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     f
   |
   o  changeset:   5:7b4e2f4b7bcd
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     e
   |
   o  changeset:   4:00f1c5383965
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     d
   |
   o  changeset:   3:65a9a84f33fd
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     c
   |
   o  changeset:   2:da6535b52e45
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     b
   |
   o  changeset:   1:c1f09da44841
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     a
   |
   o  changeset:   0:1715188a53c7
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     Initial commit
   
 
 edit the history
   $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
   merging e
   warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
   Fix up the change (pick 39522b764e3d)
   (hg histedit --continue to resume)
 
 abort the edit
   $ hg histedit --abort 2>&1 | fixbundle
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
 
 second edit set
 
   $ hg log --graph
   @  changeset:   7:39522b764e3d
   |  tag:         tip
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     does not commute with e
   |
   o  changeset:   6:500cac37a696
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     f
   |
   o  changeset:   5:7b4e2f4b7bcd
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     e
   |
   o  changeset:   4:00f1c5383965
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     d
   |
   o  changeset:   3:65a9a84f33fd
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     c
   |
   o  changeset:   2:da6535b52e45
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     b
   |
   o  changeset:   1:c1f09da44841
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     a
   |
   o  changeset:   0:1715188a53c7
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     Initial commit
   
 
 edit the history
   $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
   merging e
   warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
   Fix up the change (pick 39522b764e3d)
   (hg histedit --continue to resume)
 
 fix up
   $ echo 'I can haz no commute' > e
   $ hg resolve --mark e
   (no more unresolved files)
   continue: hg histedit --continue
   $ hg histedit --continue 2>&1 | fixbundle
   merging e
   warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
   Fix up the change (pick 7b4e2f4b7bcd)
   (hg histedit --continue to resume)
 We forcibly enable curses here so we can verify that continuing works
 with curses enabled.
   $ hg histedit --continue --config ui.interactive=true \
   >   --config ui.interface=curses 2>&1 | fixbundle
   abort: unresolved merge conflicts (see 'hg help resolve')
 
 This failure is caused by 7b4e2f4b7bcd "e" not rebasing the non commutative
 former children.
 
 just continue this time
   $ hg revert -r 'p1()' e
 make sure the to-be-empty commit doesn't screw up the state (issue5545)
   $ hg histedit --continue 2>&1 | fixbundle
   abort: unresolved merge conflicts (see 'hg help resolve')
   $ hg resolve --mark e
   (no more unresolved files)
   continue: hg histedit --continue
   $ hg histedit --continue 2>&1 | fixbundle
   7b4e2f4b7bcd: skipping changeset (no changes)
 
 log after edit
   $ hg log --graph
   @  changeset:   6:7efe1373e4bc
   |  tag:         tip
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     f
   |
   o  changeset:   5:e334d87a1e55
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     does not commute with e
   |
   o  changeset:   4:00f1c5383965
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     d
   |
   o  changeset:   3:65a9a84f33fd
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     c
   |
   o  changeset:   2:da6535b52e45
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     b
   |
   o  changeset:   1:c1f09da44841
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     a
   |
   o  changeset:   0:1715188a53c7
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     Initial commit
   
 
 start over
 
   $ cd ..
 
   $ initrepo r2
   $ cd r2
   $ rm $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
   $ hg log --template 'mess {node|short} {rev} {desc}\n' -r 7 >> $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
   $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
   $ cat $EDITED
   pick 65a9a84f33fd 3 c
   pick 00f1c5383965 4 d
   mess 39522b764e3d 7 does not commute with e
   pick 7b4e2f4b7bcd 5 e
   pick 500cac37a696 6 f
 
 edit the history, this time with a fold action
   $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
   merging e
   warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
   Fix up the change (mess 39522b764e3d)
   (hg histedit --continue to resume)
 
   $ echo 'I can haz no commute' > e
   $ hg resolve --mark e
   (no more unresolved files)
   continue: hg histedit --continue
   $ hg histedit --continue 2>&1 | fixbundle
   merging e
   warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
   Fix up the change (pick 7b4e2f4b7bcd)
   (hg histedit --continue to resume)
 second edit also fails, but just continue
   $ hg revert -r 'p1()' e
   $ hg resolve --mark e
   (no more unresolved files)
   continue: hg histedit --continue
   $ hg histedit --continue 2>&1 | fixbundle
   7b4e2f4b7bcd: skipping changeset (no changes)
 
 post message fix
   $ hg log --graph
   @  changeset:   6:7efe1373e4bc
   |  tag:         tip
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     f
   |
   o  changeset:   5:e334d87a1e55
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     does not commute with e
   |
   o  changeset:   4:00f1c5383965
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     d
   |
   o  changeset:   3:65a9a84f33fd
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     c
   |
   o  changeset:   2:da6535b52e45
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     b
   |
   o  changeset:   1:c1f09da44841
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     a
   |
   o  changeset:   0:1715188a53c7
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     Initial commit
   
 
+An invalid editor shouldn't leave the user in a broken state:
+  $ EDITOR=totally-not-a-thing-unsensible-editor-value hg histedit 4
+
   $ cd ..