From: Jeff King <peff@peff.net>
Date: Tue, 14 Feb 2017 17:27:45 +0000 (-0500)
Subject: show-branch: store resolved head in heap buffer
X-Git-Tag: v2.12.2~14^2~1
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/d9e557a320bd4695bccad873e176562489b2d199?hp=d9e557a320bd4695bccad873e176562489b2d199

show-branch: store resolved head in heap buffer

We resolve HEAD and copy the result to a fixed-size buffer
with memcpy, never checking that it actually fits. This bug
dates back to 8098a178b (Add git-symbolic-ref, 2005-09-30).
Before that we used readlink(), which took a maximum buffer
size.

We can fix this by using resolve_refdup(), which duplicates
the buffer on the heap. That also lets us just check
for a NULL pointer to see if we have resolved HEAD, and
drop the extra head_p variable.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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