2 files changed, 10 insertions, 10 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 80626bc0c2a..c47a6402e81 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,7 @@
 2011-06-18  Paul Eggert  <eggert@cs.ucla.edu>
 
+        * fns.c (Ffillarray): Don't assume bool vector size fits in 'int'.
+
         * alloc.c (Fmake_bool_vector): Avoid unnecessary multiplication.
 
         * fns.c (concat): Catch string overflow earlier.
diff --git a/src/fns.c b/src/fns.c
index 4c1505ab0f1..7b303ff3836 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -2188,19 +2188,17 @@ ARRAY is a vector, string, char-table, or bool-vector.  */)
   else if (BOOL_VECTOR_P (array))
     {
       register unsigned char *p = XBOOL_VECTOR (array)->data;
-      int size_in_chars
-        = ((XBOOL_VECTOR (array)->size + BOOL_VECTOR_BITS_PER_CHAR - 1)
+      EMACS_INT size = XBOOL_VECTOR (array)->size;
+      EMACS_INT size_in_chars
+        = ((size + BOOL_VECTOR_BITS_PER_CHAR - 1)
            / BOOL_VECTOR_BITS_PER_CHAR);
 
-      charval = (! NILP (item) ? -1 : 0);
-      for (idx = 0; idx < size_in_chars - 1; idx++)
-        p[idx] = charval;
-      if (idx < size_in_chars)
+      if (size_in_chars)
         {
-          /* Mask out bits beyond the vector size.  */
-          if (XBOOL_VECTOR (array)->size % BOOL_VECTOR_BITS_PER_CHAR)
-            charval &= (1 << (XBOOL_VECTOR (array)->size % BOOL_VECTOR_BITS_PER_CHAR)) - 1;
-          p[idx] = charval;
+          memset (p, ! NILP (item) ? -1 : 0, size_in_chars);
+
+          /* Clear any extraneous bits in the last byte.  */
+          p[size_in_chars - 1] &= (1 << (size % BOOL_VECTOR_BITS_PER_CHAR)) - 1;
         }
     }
   else