From: Junio C Hamano <junkio@cox.net>
Date: Wed, 24 May 2006 04:59:13 GMT
Subject: Re: [PATCH] Add a test-case for git-apply trying to add an ending line
Message-ID: <7v8xosqaqm.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <Pine.LNX.4.64.0605231905470.5623@g5.osdl.org>

Linus Torvalds <torvalds@osdl.org> writes:

> On Tue, 23 May 2006, Junio C Hamano wrote:
>
>> The issue is if we can reliably tell if there is such an EOF
>> context by looking at the diff.  Not having the same number of
>> lines that starts with ' ' in the hunk is not really a nice way
>> of doing so (you could make a unified diff that does not have
>> trailing context at all), and I do not offhand think of a good
>> way to do so.
>
> We can. Something like this should do it.
>
> (The same thing could be done for "match_beginning", perhaps).

But this is exactly what I said I had trouble with in the above.

In the extreme case, wouldn't this make git apply to refuse to
apply a self generated patch with 0-line context?  IOW,

        $ git checkout -- foo ;# reset to indexed version
	$ edit foo
        $ git diff -U0 >P.diff
        $ git checkout -- foo ;# reset to indexed version
        $ git apply <P.diff

would fail, even though it _should_ cleanly apply.

I'd admit that trying to apply a patch without context like the
above example _is_ insane, and I realize that I am making this
problem unsolvable by refusing the heuristics to consider that
the patch is anchored at the end when we do not see any trailing
context.  But somehow it feels wrong...