* lisp.h (CHECK_VECTOR_OR_STRING): Return number of elements

or characters in string, respectively.  Add comment.
* fringe.c (Fdefine_fringe_bitmap):
* fns.c (Fsubstring, substring_both): Use it.
* keymap.c (Fdefine_key, Flookup_key):
* macros.c (Fstart_kbd_macro): Likewise.  Avoid call to Flength.

1 files changed, 11 insertions, 15 deletions

diff --git a/src/macros.c b/src/macros.c
index acba125edc5..c73986abd34 100644
--- a/src/macros.c
+++ b/src/macros.c
@@ -80,28 +80,24 @@ macro before appending to it.  */)
     }
   else
     {
-      ptrdiff_t i;
-      EMACS_INT len;
+      const ptrdiff_t incr = 30;
+      ptrdiff_t i, len;
       bool cvt;
 
       /* Check the type of last-kbd-macro in case Lisp code changed it.  */
-      CHECK_VECTOR_OR_STRING (KVAR (current_kboard, Vlast_kbd_macro));
+      len = CHECK_VECTOR_OR_STRING (KVAR (current_kboard, Vlast_kbd_macro));
 
-      len = XINT (Flength (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 + 30)
-        {
-          if (PTRDIFF_MAX < MOST_POSITIVE_FIXNUM + 30
-              && PTRDIFF_MAX < len + 30)
-            memory_full (SIZE_MAX);
-          current_kboard->kbd_macro_buffer =
-            xpalloc (current_kboard->kbd_macro_buffer,
-                     &current_kboard->kbd_macro_bufsize,
-                     len + 30 - current_kboard->kbd_macro_bufsize, -1,
-                     sizeof *current_kboard->kbd_macro_buffer);
-        }
+      if (current_kboard->kbd_macro_bufsize < len + incr)
+        current_kboard->kbd_macro_buffer =
+          xpalloc (current_kboard->kbd_macro_buffer,
+                   &current_kboard->kbd_macro_bufsize,
+                   len + incr - current_kboard->kbd_macro_bufsize, -1,
+                   sizeof *current_kboard->kbd_macro_buffer);
 
       /* Must convert meta modifier when copying string to vector.  */
       cvt = STRINGP (KVAR (current_kboard, Vlast_kbd_macro));