From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 11 Mar 2012 18:43:52 GMT
Subject: Re: [PATCH] apply: reallocate the postimage buffer when needed
Message-ID: <7v8vj7x9jr.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1331475857-15169-1-git-send-email-cmn@elego.de>

Carlos Martín Nieto <cmn@elego.de> writes:

> Blame says Junio and Giuseppe were the last ones to touch this part of
> the code, so there you go.

Whatever you do in your fix, this comment block needs to be updated:

	/*
	 * Adjust the common context lines in postimage. This can be
	 * done in-place when we are just doing whitespace fixing,
	 * which does not make the string grow, but needs a new buffer
	 * when ignoring whitespace causes the update, since in this case
	 * we could have e.g. tabs converted to multiple spaces.
	 * We trust the caller to tell us if the update can be done
	 * in place (postlen==0) or not.
	 */

The second sentence used to be true for a long time (if you indented
your line with too many spaces, we removed them and replaced with
fewer number of tabs; if you had spaces before a tab, we removed
them; if you added unnecessary whitespaces at the end, we removed
them), but ceased to be so when Python style "indent must be spaces"
was added.

So I think this either always needs to re-allocate, or the caller
has to tell it by other means than "!postlen" the need for
reallocation.

I wasn't involved in the "apply while ignoring whitespace
differences", so Giuseppe may be able to notice other mode of
beakages in this and fuzzy_matchlines() function.  The commit to be
stared at is 86c91f9 (git apply: option to ignore whitespace
differences, 2009-08-04).

Thanks.