(make_gap_larger): Don't make as many assumptions about the

representation of Lisp integers.
Reported by MJ Chan <mjchan.inbox@gmail.com>.

1 files changed, 10 insertions, 10 deletions

diff --git a/src/insdel.c b/src/insdel.c
index bdd450558bd..0faf3c07227 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -512,16 +512,16 @@ make_gap_larger (EMACS_INT nbytes_added)
   /* If we have to get more space, get enough to last a while.  */
   nbytes_added += 2000;
 
-  /* Don't allow a buffer size that won't fit in an int
-     even if it will fit in a Lisp integer.
-     That won't work because so many places use `int'.
-
-     Make sure we don't introduce overflows in the calculation.  */
-
-  if (Z_BYTE - BEG_BYTE + GAP_SIZE
-      >= (((EMACS_INT) 1 << (min (VALBITS, BITS_PER_INT) - 1)) - 1
-	  - nbytes_added))
-    error ("Buffer exceeds maximum size");
+  { EMACS_INT total_size = Z_BYTE - BEG_BYTE + GAP_SIZE + nbytes_added;
+    if (total_size < 0
+	/* Don't allow a buffer size that won't fit in a Lisp integer.  */
+	|| total_size != XINT (make_number (total_size))
+	/* Don't allow a buffer size that won't fit in an int
+	   even if it will fit in a Lisp integer.
+	   That won't work because so many places still use `int'.  */
+	|| total_size != (EMACS_INT) (int) total_size)
+      error ("Buffer exceeds maximum size");
+  }
 
   enlarge_buffer_text (current_buffer, nbytes_added);