[PATCH V3] revert: add an experimental config to use inverted selection

[Pierre-Yves David]

On 05/29/2015 05:52 PM, Laurent Charignon wrote:
> # HG changeset patch
> # User Laurent Charignon <lcharignon at fb.com>
> # Date 1432930312 25200
> #      Fri May 29 13:11:52 2015 -0700
> # Node ID 83c944bf69641bcb5dd8d97d2ff2d514ba765ed5
> # Parent  a4acf019dd5b72e91a1b1321d80d298033be8111
> revert: add an experimental config to use inverted selection
>
> We had a discussion on the list about the interactive ui for revert. This patch
> adds a flag to allow people to test the second alternative (referred to as
> proposition 2 on the mailing list). It effectively inverts the signs in the
> diff displayed to match the output of hg diff. A test is added to show an
> example.
>
> By setting the following flag in the config, one can try proposition 2:
> [experimental]
>   invertedinteractive=True

This commit message disagree with its code.

>
> diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
> --- a/mercurial/cmdutil.py
> +++ b/mercurial/cmdutil.py
> @@ -3138,10 +3138,21 @@
>           diffopts = patch.difffeatureopts(repo.ui, whitespace=True)
>           diffopts.nodates = True
>           diffopts.git = True
> -        diff = patch.diff(repo, None, ctx.node(), m, opts=diffopts)
> +        reversehunks =  repo.ui.configbool('experimental',
> +                                           'revertalternateinteractivemode',

I'm notsurefanofthisextendedname but I'm not sure I've a better idea and 
this is in experimental anyway.

I would take the patch if the tests were more complete. See feedback below.

> +                                           False)
> +        if reversehunks:
> +            diff = patch.diff(repo, ctx.node(), None, m, opts=diffopts)
> +        else:
> +            diff = patch.diff(repo, None, ctx.node(), m, opts=diffopts)
>           originalchunks = patch.parsepatch(diff)
> +
>           try:
> +
>               chunks = recordfilter(repo.ui, originalchunks)
> +            if reversehunks:
> +                chunks = patch.reversehunks(chunks)
> +
>           except patch.PatchError, err:
>               raise util.Abort(_('error parsing patch: %s') % err)
>
> diff --git a/mercurial/patch.py b/mercurial/patch.py
> --- a/mercurial/patch.py
> +++ b/mercurial/patch.py
> @@ -1383,6 +1383,77 @@
>               return s
>       return s[:i]
>
> +def reversehunks(hunks):
> +    '''reverse the signs in the hunks given as argument
> +
> +    This function operates on hunks coming out of patch.filterpatch, that is
> +    a list of the form: [header1, hunk1, hunk2, header2...]. Example usage:
> +
> +    >>> rawpatch = """diff --git a/folder1/g b/folder1/g
> +    ... --- a/folder1/g
> +    ... +++ b/folder1/g
> +    ... @@ -1,3 +1,4 @@
> +    ... +firstline
> +    ...  c
> +    ...  1
> +    ...  2
> +    ... @@ -5,3 +6,4 @@
> +    ...  4
> +    ...  5
> +    ...  d
> +    ... +lastline"""

This test not very broad. I would expect

- some line removal
- some change in the middle of a file (most common case)
- some context in the middle of changes.


> +    After parsepatch hunks look like: [header1, header2, ...]:
> +    >>> hunks = parsepatch(rawpatch)
> +
> +    After filterpatch hunks look like: [header1, hunk1, hunk2, header2...]
> +    We expand the list of headers by appending their respective hunks:
> +    >>> hunkscomingfromfilterpatch = []
> +    >>> for h in hunks:
> +    ...     hunkscomingfromfilterpatch.append(h)
> +    ...     hunkscomingfromfilterpatch.extend(h.hunks)
> +
> +    Actual hunk inversion:
> +    >>> reversedhunks = reversehunks(hunkscomingfromfilterpatch)

small nits (not sure if so much comment are necessary about operation 
necessary but not the one who are tested)

-- 
Pierre-Yves David