[PATCH 2 of 3 STABLE] context: ability to manipulate diff feature opt-ins

[Yuya Nishihara]

On Sat, 18 Jul 2015 14:24:30 -0700, Gregory Szorc wrote:
> # HG changeset patch
> # User Gregory Szorc <gregory.szorc at gmail.com>
> # Date 1437254506 25200
> #      Sat Jul 18 14:21:46 2015 -0700
> # Node ID b6ab3a470c0196159e8931c8c6dd4b5c4a52a4f6
> # Parent  d88519184df5f9538b4f9294bee7a595d5dce6d2
> context: ability to manipulate diff feature opt-ins
> 
> Before this patch, basectx.diff respected all diff options. Sometimes
> consumers want to opt out of certain classes of diff features.
> 
> Change the function to call patch.difffeatureopts instead of
> diffallopts and allow the various features to be opted out of via
> arguments.
> 
> diff --git a/mercurial/context.py b/mercurial/context.py
> --- a/mercurial/context.py
> +++ b/mercurial/context.py
> @@ -268,15 +268,23 @@ class basectx(object):
>                                include, exclude, default,
>                                auditor=r.auditor, ctx=self,
>                                listsubrepos=listsubrepos, badfn=badfn)
>  
> -    def diff(self, ctx2=None, match=None, **opts):
> -        """Returns a diff generator for the given contexts and matcher"""
> +    def diff(self, ctx2=None, match=None, allowgit=True, allowwhitespace=True,
> +             allowformatchanging=True, **opts):
> +        """Returns a diff generator for the given contexts and matcher.
> +
> +        The various allow* arguments control whether the diff features under
> +        that category are respected. See patch.difffeatureopts.
> +        """
>          if ctx2 is None:
>              ctx2 = self.p1()
>          if ctx2 is not None:
>              ctx2 = self._repo[ctx2]
> -        diffopts = patch.diffopts(self._repo.ui, opts)
> +        diffopts = patch.difffeatureopts(self._repo.ui, opts=opts,
> +                                         git=allowgit,
> +                                         whitespace=allowwhitespace,
> +                                         formatchanging=allowformatchanging)
>          return patch.diff(self._repo, ctx2, self, match=match, opts=diffopts)

I'm noob about this API, but I think patch.diff*opts() exists to pack various
diff-related options into one argument. It seems this change goes the opposite
direction.

Instead, maybe we can change templatekw.showdiffstat() to not use ctx.diff() ?