[PATCH/RFH] pp_header(): work around possible memory corruption

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

add_user_info() possibly adds way more than just the commit header line. 
In fact, it sometimes needs so much more space that there is a buffer 
overrun, leading to an ugly crash. For example, the date is printed in its 
own line, and usually takes up more space than the equivalent Unix epoch.

So, for good measure, add 80 characters (a full line) to the allocated 
space, in addition to the header line length.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>

---

	I have no idea if 80 is a good value, and if other places
	need an equivalent fix up, too.

	But I needed this patch in a hurry...

 commit.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/commit.c b/commit.c
index f778bf4..03436b1 100644
--- a/commit.c
+++ b/commit.c
@@ -997,7 +997,7 @@ static void pp_header(enum cmit_fmt fmt,
 			len = linelen;
 			if (fmt == CMIT_FMT_EMAIL)
 				len = bound_rfc2047(linelen, encoding);
-			ALLOC_GROW(*buf_p, *ofs_p + len, *space_p);
+			ALLOC_GROW(*buf_p, *ofs_p + len + 80, *space_p);
 			dst = *buf_p + *ofs_p;
 			*ofs_p += add_user_info("Author", fmt, dst,
 						line + 7, dmode, encoding);
@@ -1008,7 +1008,7 @@ static void pp_header(enum cmit_fmt fmt,
 			len = linelen;
 			if (fmt == CMIT_FMT_EMAIL)
 				len = bound_rfc2047(linelen, encoding);
-			ALLOC_GROW(*buf_p, *ofs_p + len, *space_p);
+			ALLOC_GROW(*buf_p, *ofs_p + len + 80, *space_p);
 			dst = *buf_p + *ofs_p;
 			*ofs_p += add_user_info("Commit", fmt, dst,
 						line + 10, dmode, encoding);