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 =
Test for changeset ba7c74081861
(update dirstate correctly for non-branchmerge updates)
$ hg init a
$ cd a
$ echo a > a
$ hg add a
$ hg commit -m a
$ cd ..
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd a
$ hg mv a b
$ hg commit -m move
$ echo b >> b
$ hg commit -m b
$ cd ../b
$ hg pull ../a
pulling from ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
(run 'hg update' to get a working copy)
$ hg update
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cd ..