[PATCH] merge: when --tool is specified, disable HGMERGE by setting to empty string

[Steve Borho]

On Tue, Oct 19, 2010 at 10:57 AM, Mads Kiilerich <mads at kiilerich.com> wrote:
> On 10/19/2010 06:20 AM, Steve Borho wrote:
>>
>> # HG changeset patch
>> # User Steve Borho<steve at borho.org>
>> # Date 1287462014 18000
>> # Node ID 096444ceebdf61e58466ad1c85bbca1019fab76b
>> # Parent  ef5eaf53f4f73ee1e225f5c524cb51ed1e7bb973
>> merge: when --tool is specified, disable HGMERGE by setting to empty
>> string
>>
>> HGMERGE has different semantics than ui.merge.  HGMERGE should hold the
>> name
>> on an executable in your path, or an absolute tool path.  As such, it's
>> not
>> safe to simply copy the user's specified --tool value into HGMERGE.
>>  Instead,
>> we disable HGMERGE by setting it to an empty string.
>
> Sorry for being a bit late here ...
>
> My intuition - which in this case doesn't directly conflict with the help
> texts - says that this option should guarantee that the specified tool is
> used to merge all files that are merged, no matter what.
>
> But AFAICS it doesn't overrule merge-patterns? I think that one of the use
> cases for this option is to overrule merge-patterns for individual files.
>
> I think it would be better to introduce a new 8th merge tool selection
> option at the top of filemerge._picktool, rather than overloading ui.merge
> and trying to patch HGMERGE.

Hmm, called my bluff.   Ok, how about ui.forcemerge (not documented in
hgrc(1)) that takes precedence over HGMERGE and bypasses file pattern
checks?  The merge and resolve commands would need to clear the config
value at their finish.

> Btw: Isn't it a problem to force config settings in ui objects which might
> have a lifetime that spans several "API" calls? (With reference to
> http://www.selenic.com/pipermail/mercurial-devel/2010-October/025387.html )
>
> Finally: Wouldn't it be convenient if --tool= (without arguments) meant
> internal:fail ?

It wasn't obvious to me how to differentiate between:

hg resolve --tool= FILE
and
hg resolve FILE

Otherwise, I agree that would be preferred behavior.

-- 
Steve Borho