Backport 20156 fix (stack corruption)

Fixes: debbugs:20156

* src/fontset.c (fontset_pattern_regexp): Backport: Replace + 1 with
+ 3 in alloca (tiny change)

2 files changed, 7 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 90908fcf759..060486b4ab3 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2015-03-22  John F Carr <jfc@mit.edu>
+
+        * fontset.c (fontset_pattern_regexp): Backport: Replace + 1 with
+        + 3 in alloca (Bug#20156) (tiny change)
+
 2015-03-12  Glenn Morris  <rgm@gnu.org>
 
         * frame.h (x_set_bitmap_icon): Don't set the icon if icon-type is
diff --git a/src/fontset.c b/src/fontset.c
index d9aa99d05f5..5772cc830c8 100644
--- a/src/fontset.c
+++ b/src/fontset.c
@@ -1097,9 +1097,9 @@ fontset_pattern_regexp (Lisp_Object pattern)
          we convert "*" to "[^-]*" which is much faster in regular
          expression matching.  */
       if (ndashes < 14)
-        p1 = regex = alloca (SBYTES (pattern) + 2 * nstars + 2 * nescs + 1);
+        p1 = regex = alloca (SBYTES (pattern) + 2 * nstars + 2 * nescs + 3);
       else
-        p1 = regex = alloca (SBYTES (pattern) + 5 * nstars + 2 * nescs + 1);
+        p1 = regex = alloca (SBYTES (pattern) + 5 * nstars + 2 * nescs + 3);
 
       *p1++ = '^';
       for (p0 = SDATA (pattern); *p0; p0++)