* macros.c (Fstart_kbd_macro): Avoid need for overflow check.

2 files changed, 3 insertions, 6 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 75c2a01d2d2..53795742131 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,6 +1,6 @@
 2014-07-14  Paul Eggert  <eggert@cs.ucla.edu>
 
-        * macros.c (Fstart_kbd_macro): Simplify.
+        * macros.c (Fstart_kbd_macro): Avoid need for overflow check.
         This works around a GCC compiler bug when Emacs is configured with
         --enable-gcc-warnings.
 
diff --git a/src/macros.c b/src/macros.c
index 07667f09431..4730a8becc9 100644
--- a/src/macros.c
+++ b/src/macros.c
@@ -87,16 +87,13 @@ macro before appending to it.  */)
       /* Check the type of last-kbd-macro in case Lisp code changed it.  */
       len = CHECK_VECTOR_OR_STRING (KVAR (current_kboard, Vlast_kbd_macro));
 
-      if (INT_ADD_OVERFLOW (len, incr))
-        memory_full (SIZE_MAX);
-
       /* Copy last-kbd-macro into the buffer, in case the Lisp code
          has put another macro there.  */
-      if (current_kboard->kbd_macro_bufsize < len + incr)
+      if (current_kboard->kbd_macro_bufsize - incr < len)
         current_kboard->kbd_macro_buffer =
           xpalloc (current_kboard->kbd_macro_buffer,
                    &current_kboard->kbd_macro_bufsize,
-                   len + incr - current_kboard->kbd_macro_bufsize, -1,
+                   len - current_kboard->kbd_macro_bufsize + incr, -1,
                    sizeof *current_kboard->kbd_macro_buffer);
 
       /* Must convert meta modifier when copying string to vector.  */