Re: [PATCH 1/3] apply: get rid of useless x < 0 comparison on a size_t type

On Sun, Nov 6, 2011 at 7:35 PM, Junio C Hamano [off-list ref] wrote:

Ævar Arnfjörð Bjarmason  [off-list ref] writes:

quoted

This check was originally added in v1.6.5-rc0~53^2 by Giuseppe Bilotta
while adding an option to git-apply to ignore whitespace differences.

I agree that these quantities can never be negative, so I'll apply the
patch as is.

I agree too. In fact I spotted this some time ago when I started
compiling git with Clang but never found the time to look into it.

But I have this suspicion that this was a rather sloppy defensive check to
protect this codepath against potential breakage in another codepath (most
likely update_pre_post_images() touched by the same patch) that adjusts
image->line[].len the caller of this function uses to feed these two
parameters. Giuseppe may have been not confident enough that the code
added to that function ensures not to undershoot when it reduces "len", or
something.

Giuseppe, can you explain what is going on?

No, I can't, so I guess the sloppy coding is the right motivation. I
remember working this patch from a rather older submission that was
never followed-up to, so my guess is that I just forgot to clean it up
properly, and during review the focus was obviously on other aspects
of the submission too. Also, having a look at the current caller of
the function, I don't see how the check would even be needed.

-- 
Giuseppe "Oblomov" Bilotta