extdiff: allow a preconfigured merge-tool to be invoked
There are three ways to configure an extdiff tool:
1) cmd.tool = (/path/to/exe optional)
2) tool = (path/to/exe optional)
3) tool = sometool someargs
Previously, if no executable is specified in the first two forms, the named tool
must be in $PATH, or the invocation fails. Since the [merge-tools] section
already has the path to the diff executable, and/or the registry keys to find
the executable on Windows, reuse that configuration for forms 1 and 2 instead of
failing. We already fallback to [diff-tools] and then [merge-tools] for program
arguments if they aren't specified in the [extdiff] section.
Since this additional lookup only occurs if an executable is not on the $PATH
for the named tool, this is backwards compatible. For now, we assume the user
knows what he is doing if a path is provided.
This change allows a configuration file like this (assuming beyondcompare3 is
configured in merge-tools), instead of hardcoding system specific a path:
[extdiff]
beyondcompare3 =
$ hg init t
$ cd t
$ echo 1 > foo
$ hg ci -Am m
adding foo
$ cd ..
$ hg clone t tt
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd tt
$ echo 1.1 > foo
$ hg ci -Am m
$ cd ../t
$ echo 1.2 > foo
$ hg ci -Am m
Should not update:
$ hg pull -u ../tt
pulling from ../tt
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
not updating: not a linear update
(merge or update --check to force update)
$ cd ../tt
Should not update:
$ hg pull -u ../t
pulling from ../t
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
not updating: not a linear update
(merge or update --check to force update)
$ HGMERGE=true hg merge
merging foo
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -mm
$ cd ../t
Should work:
$ hg pull -u ../tt
pulling from ../tt
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (-1 heads)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ..