filemerge: move check for identical sides out of filemerge()
`filemerge.filemerge()` returns `None` if no merge was necessary
because the two sides were identical. I don't think it should be that
function's responsibility to handle that case; we should ideally not
even call `filemerge.filemerge()` if the two inputs identical. This
patch therefore moves the check out to the caller (`mergestate.py`).
The largefiles test changed because we now notice that the two sides
made the same change, so we don't consider it a merge. Also note that
the new message better matches the line above it in the test output.
Differential Revision: https://phab.mercurial-scm.org/D12154
$ hg init
$ echo foo > a
$ hg add a
$ hg commit -m "1"
$ echo bar > b
$ hg add b
$ hg remove a
Should show a removed and b added:
$ hg status
A b
R a
$ hg revert --all
forgetting b
undeleting a
Should show b unknown and a back to normal:
$ hg status
? b
$ rm b
$ hg co -C 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo foo-a > a
$ hg commit -m "2a"
$ hg co -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo foo-b > a
$ hg commit -m "2b"
created new head
$ HGMERGE=true hg merge 1
merging a
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
Should show foo-b:
$ cat a
foo-b
$ echo bar > b
$ hg add b
$ rm a
$ hg remove a
Should show a removed and b added:
$ hg status
A b
R a
Revert should fail:
$ hg revert
abort: uncommitted merge with no revision specified
(use 'hg update' or see 'hg help revert')
[10]
Revert should be ok now:
$ hg revert -r2 --all
forgetting b
undeleting a
Should show b unknown and a marked modified (merged):
$ hg status
M a
? b
Should show foo-b:
$ cat a
foo-b