documentation: add some internals documentation about bid merge
This is an important algorithm that was only documented on the wiki so far.
Some update to the algorithm (and associated doc) is to expected in the future
since the bid merge algorithm is bug-ridden when it comes to file deletion comes
to play.
Differential Revision: https://phab.mercurial-scm.org/D8711
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> [phases]
> publish=False
> [merge]
> EOF
$ hg init repo
$ cd repo
$ echo a > a
$ echo b > b
$ hg commit -qAm ab
$ echo c >> a
$ echo c >> b
$ hg commit -qAm c
$ hg up -q ".^"
$ echo d >> a
$ echo d >> b
$ hg commit -qAm d
Testing on-failure=continue
$ echo on-failure=continue >> $HGRCPATH
$ hg rebase -s 1 -d 2 --tool false
rebasing 1:1f28a51c3c9b "c"
merging a
merging b
merging a failed!
merging b failed!
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Testing on-failure=halt
$ echo on-failure=halt >> $HGRCPATH
$ hg rebase -s 1 -d 2 --tool false
rebasing 1:1f28a51c3c9b "c"
merging a
merging b
merging a failed!
merge halted after failed merge (see hg resolve)
[1]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Testing on-failure=prompt
$ cat <<EOS >> $HGRCPATH
> [merge]
> on-failure=prompt
> [ui]
> interactive=1
> EOS
$ cat <<EOS | hg rebase -s 1 -d 2 --tool false
> y
> n
> EOS
rebasing 1:1f28a51c3c9b "c"
merging a
merging b
merging a failed!
continue merge operation (yn)? y
merging b failed!
continue merge operation (yn)? n
merge halted after failed merge (see hg resolve)
[1]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Check that successful tool with failed post-check halts the merge
$ cat <<EOS >> $HGRCPATH
> [merge-tools]
> true.check=changed
> EOS
$ cat <<EOS | hg rebase -s 1 -d 2 --tool true
> y
> n
> n
> EOS
rebasing 1:1f28a51c3c9b "c"
merging a
merging b
output file a appears unchanged
was merge successful (yn)? y
output file b appears unchanged
was merge successful (yn)? n
merging b failed!
continue merge operation (yn)? n
merge halted after failed merge (see hg resolve)
[1]
$ hg resolve --list
R a
U b
$ hg rebase --abort
rebase aborted
Check that conflicts with conflict check also halts the merge
$ cat <<EOS >> $HGRCPATH
> [merge-tools]
> true.check=conflicts
> true.premerge=keep
> [merge]
> on-failure=halt
> EOS
$ hg rebase -s 1 -d 2 --tool true
rebasing 1:1f28a51c3c9b "c"
merging a
merging b
merging a failed!
merge halted after failed merge (see hg resolve)
[1]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Check that always-prompt also can halt the merge
$ cat <<EOS | hg rebase -s 1 -d 2 --tool true --config merge-tools.true.check=prompt
> y
> n
> EOS
rebasing 1:1f28a51c3c9b "c"
merging a
merging b
was merge of 'a' successful (yn)? y
was merge of 'b' successful (yn)? n
merging b failed!
merge halted after failed merge (see hg resolve)
[1]
$ hg resolve --list
R a
U b
$ hg rebase --abort
rebase aborted
Check that successful tool otherwise allows the merge to continue
$ hg rebase -s 1 -d 2 --tool echo --keep --config merge-tools.echo.premerge=keep
rebasing 1:1f28a51c3c9b "c"
merging a
merging b
$TESTTMP/repo/a *a~base* *a~other* (glob)
$TESTTMP/repo/b *b~base* *b~other* (glob)