From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sat, 18 Jun 2011 15:08:31 +0000 (-0700)
Subject: * fns.c (concat): Catch string overflow earlier.
X-Git-Tag: emacs-pretest-24.0.90~104^2~473^2~60
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=a498d7f4f8ce688079d32cac4858ba78d2a9081e;p=emacs.git

* fns.c (concat): Catch string overflow earlier.

Do not rely on integer wraparound.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 79d9b636e09..b9cf18cedd9 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,8 @@
 2011-06-18  Paul Eggert  <eggert@cs.ucla.edu>
 
+	* fns.c (concat): Catch string overflow earlier.
+	Do not rely on integer wraparound.
+
 	* dispextern.h (struct it.overlay_strings_charpos): EMACS_INT, not int.
 
 2011-06-17  Paul Eggert  <eggert@cs.ucla.edu>
diff --git a/src/fns.c b/src/fns.c
index a19c886e3e1..4c1505ab0f1 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -565,8 +565,8 @@ concat (ptrdiff_t nargs, Lisp_Object *args,
 	}
 
       result_len += len;
-      if (result_len < 0)
-	error ("String overflow");
+      if (STRING_BYTES_BOUND < result_len)
+	string_overflow ();
     }
 
   if (! some_multibyte)