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 =
http://mercurial.selenic.com/bts/issue842
$ hg init
$ echo foo > a
$ hg ci -Ama
adding a
$ hg up -r0000
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo bar > a
Should issue new head warning:
$ hg ci -Amb
adding a
created new head
$ hg up -r0000
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo stuffy > a
Should not issue new head warning:
$ hg ci -q -Amc
$ hg up -r0000
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo crap > a
$ hg branch testing
marked working directory as branch testing
(branches are permanent and global, did you want a bookmark?)
Should not issue warning:
$ hg ci -q -Amd