view tests/test-rebase-transaction.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

#testcases continuecommand continueflag
Rebasing using a single transaction

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > drawdag=$TESTDIR/drawdag.py
  > 
  > [rebase]
  > singletransaction=True
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: {desc}"
  > EOF

#if continueflag
  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > continue = rebase --continue
  > EOF
#endif

Check that a simple rebase works

  $ hg init simple && cd simple
  $ hg debugdrawdag <<'EOF'
  >   Z
  >   |
  >   | D
  >   | |
  >   | C
  >   | |
  >   Y B
  >   |/
  >   A
  > EOF
- We should only see one status stored message. It comes from the start.
  $ hg rebase --debug -b D -d Z | grep 'status stored'
  rebase status stored
  $ hg tglog
  o  5: D
  |
  o  4: C
  |
  o  3: B
  |
  o  2: Z
  |
  o  1: Y
  |
  o  0: A
  
  $ cd ..

Check that --collapse works

  $ hg init collapse && cd collapse
  $ hg debugdrawdag <<'EOF'
  >   Z
  >   |
  >   | D
  >   | |
  >   | C
  >   | |
  >   Y B
  >   |/
  >   A
  > EOF
- We should only see two status stored messages. One from the start, one from
- cmdutil.commitforceeditor() which forces tr.writepending()
  $ hg rebase --collapse --debug -b D -d Z | grep 'status stored'
  rebase status stored
  rebase status stored
  $ hg tglog
  o  3: Collapsed revision
  |  * B
  |  * C
  |  * D
  o  2: Z
  |
  o  1: Y
  |
  o  0: A
  
  $ cd ..

With --collapse, check that conflicts can be resolved and rebase can then be
continued

  $ hg init collapse-conflict && cd collapse-conflict
  $ hg debugdrawdag <<'EOF'
  >   Z   # Z/conflict=Z
  >   |
  >   | D
  >   | |
  >   | C # C/conflict=C
  >   | |
  >   Y B
  >   |/
  >   A
  > EOF
  $ hg rebase --collapse -b D -d Z
  rebasing 1:112478962961 "B" (B)
  rebasing 3:c26739dbe603 "C" (C)
  merging conflict
  warning: conflicts while merging conflict! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ hg tglog
  o  5: D
  |
  | @  4: Z
  | |
  @ |  3: C
  | |
  | o  2: Y
  | |
  o |  1: B
  |/
  o  0: A
  
  $ hg st
  M C
  M conflict
  A B
  ? conflict.orig
  $ echo resolved > conflict
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg continue
  already rebased 1:112478962961 "B" (B) as 79bc8f4973ce
  rebasing 3:c26739dbe603 "C" (C)
  rebasing 5:d24bb333861c "D" (D tip)
  saved backup bundle to $TESTTMP/collapse-conflict/.hg/strip-backup/112478962961-b5b34645-rebase.hg
  $ hg tglog
  o  3: Collapsed revision
  |  * B
  |  * C
  |  * D
  o  2: Z
  |
  o  1: Y
  |
  o  0: A
  
  $ cd ..

With --collapse, check that the commit message editing can be canceled and
rebase can then be continued

  $ hg init collapse-cancel-editor && cd collapse-cancel-editor
  $ hg debugdrawdag <<'EOF'
  >   Z
  >   |
  >   | D
  >   | |
  >   | C
  >   | |
  >   Y B
  >   |/
  >   A
  > EOF
  $ HGEDITOR=false hg --config ui.interactive=1 rebase --collapse -b D -d Z
  rebasing 1:112478962961 "B" (B)
  rebasing 3:26805aba1e60 "C" (C)
  rebasing 5:f585351a92f8 "D" (D tip)
  transaction abort!
  rollback completed
  abort: edit failed: false exited with status 1
  [255]
  $ hg tglog
  o  5: D
  |
  | o  4: Z
  | |
  o |  3: C
  | |
  | o  2: Y
  | |
  o |  1: B
  |/
  o  0: A
  
  $ hg continue
  rebasing 1:112478962961 "B" (B)
  rebasing 3:26805aba1e60 "C" (C)
  rebasing 5:f585351a92f8 "D" (D tip)
  saved backup bundle to $TESTTMP/collapse-cancel-editor/.hg/strip-backup/112478962961-cb2a9b47-rebase.hg
  $ hg tglog
  o  3: Collapsed revision
  |  * B
  |  * C
  |  * D
  o  2: Z
  |
  o  1: Y
  |
  o  0: A
  
  $ cd ..