rust: Add type annotation to fix inference on Rust Nightly
When compiling with Rust Nightly, the im-rs crate silently makes use of the
experimental language feature for trait impl specialization. This apperently
changes public its APIs in subtle ways such that type inference of some user
code can fail where it succeeds when specialization is disabled.
This made Mercurial’s Rust unit tests have compilation errors on Nightly.
I have not managed to find the exactl root cause, but I wrote down my findings
so far at https://github.com/bodil/im-rs/issues/188
This adds type annotation to make unit tests rely less on type inference
and work around the issue.
Differential Revision: https://phab.mercurial-scm.org/D10742
$ 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')
[240]
$ 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)
[240]
$ 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)
[240]
$ 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)
[240]
$ 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)
[240]
$ 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)
[240]
$ 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)