# HG changeset patch
# User Erling Ellingsen <erlingalf@gmail.com>
# Date 1172006416 -3600
# Node ID 1ca664c964e0003ce99f6550aeeeed4ccf76851d
# Parent  178007785be82a428abb04815b44ba7d0926abcf
don't return uninitialized memory from bdiff.blocks()

bdiff.blocks() returns a dummy match at the end of both files; the
length of that chunk is never set, so it will sometimes contain random
heap garbage. There are apparently workarounds for this elsewhere:

  # bdiff sometimes gives huge matches past eof, this check eats them,

diff --git a/mercurial/bdiff.c b/mercurial/bdiff.c
--- a/mercurial/bdiff.c
+++ b/mercurial/bdiff.c
@@ -251,8 +251,8 @@ static struct hunklist diff(struct line 
 	if (pos && l.base && t) {
 		/* generate the matching block list */
 		recurse(a, b, pos, 0, an, 0, bn, &l);
-		l.head->a1 = an;
-		l.head->b1 = bn;
+		l.head->a1 = l.head->a2 = an;
+		l.head->b1 = l.head->b2 = bn;
 		l.head++;
 	}