annotate tests/test-histedit-fold-non-commute.t @ 42619:20d0e59be79b

tests: show the files fields of changelogs for many merges

I don't think there's coverage for many of the subtle cases, and I
found it hard to understand what the code is doing by reading it.  The
test takes 40s to run on a laptop, or 9s with --chg.

I have yet to find a description of what the files field is supposed
to be for merges. I thought it could be one of:
1. the files added/modified/removed relative to p1 (wouldn't seem
  useful, but `hg diff -c -r mergerev` has this behavior)
2. the files with filelog nodes not in either parent (i.e., what is
needed to create a bundle out of a commit)
3. the files added/removed/modified files by merge itself [1]

It's clearly not 1, because file contents merges are symmetric. It's
clearly not 2 because removed files and exec bit changes are
listed. It's also not 3 but I think it's intended to be 3 and the
differences are bugs.

Assuming 3, the test shows that, for merges, the list of files both
overapproximates and underapproximates. All the cases involve file
changes not in the filelog but in the manifest (existence of file
at revision, exec bit and file vs symlink).

I didn't look at all underapproximations, but they looked minor. The
two overapproximations are problematic though because they both cause
potentially long lists of files when merging cleanly.


[1] even what it means for the merge commit itself to change a file is
not completely trivial. A file in the merge being the same as in one
of the parent is too lax as it would consider that merges change
nothing when they revert all the changes done on one side. The
criteria used in the test and in the next commit for "merge didn't
touch a file" is:
- the parents and the merge all have the same file
- or, one parent didn't touch the file and the other parent contains
  the same file as the merge

Differential Revision: https://phab.mercurial-scm.org/D6612

  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > EOF

  $ modwithdate ()
  > {
  >     echo $1 > $1
  >     hg ci -m $1 -d "$2 0"
  > }

  $ 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'
  >     modwithdate a 1
  >     modwithdate b 2
  >     modwithdate c 3
  >     modwithdate d 4
  >     modwithdate e 5
  >     modwithdate f 6
  >     echo 'I can haz no commute' > e
  >     hg ci -m 'does not commute with e' -d '7 0'
  >     cd ..
  > }

  $ initrepo r
  $ cd r
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 'fold {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 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  fold 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 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 (fold 42abbb61bede)
  (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
  $ HGEDITOR=cat hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  d
  ***
  does not commute with e
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: changed d
  HG: changed e
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
keep the non-commuting change, and thus the pending change will be dropped
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg diff
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:1300355b1a54
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e2ac33269083
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

  $ cd ..

Repeat test using "roll", not "fold". "roll" folds in changes but drops message and date

  $ initrepo r2
  $ cd r2

Initial generation of the command files

  $ EDITED="$TESTTMP/editedhistory.2"
  $ 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 'roll {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 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  roll 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 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 (roll 42abbb61bede)
  (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 | grep -v '2 files removed'
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:b538bcb461be
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:317e37cb6d66
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

description is taken from rollup target commit

  $ hg log --debug --rev 4
  changeset:   4:317e37cb6d66c1c84628c00e5bf4c8c292831951
  phase:       draft
  parent:      3:092e4ce14829f4974399ce4316d59f64ef0b6725
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    4:b068a323d969f22af1296ec6a5ea9384cef437ac
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  files:       d e
  extra:       branch=default
  extra:       histedit_source=ae78f4c9d74ffa4b6cb5045001c303fe9204e890,42abbb61bede6f4366fa1e74a664343e5d558a70
  description:
  d
  
  

done with repo r2

  $ cd ..