# HG changeset patch
# User Bruno Haible <bruno@clisp.org>
# Date 1129034864 0
# Node ID bbcddcd96f1f266ccd4d34d83674423546c69ac3
# Parent  ec955d9e0ccd610a78d9e7baa416edfcd9d32a5a
Avoid integer overflow on exotic platforms.

diff --git a/lib/ChangeLog b/lib/ChangeLog
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,11 @@
+2005-10-11  Bruno Haible  <bruno@clisp.org>
+
+	* strcasecmp.c: Include limits.h.
+	(strcasecmp): Avoid integer overflow on exotic platforms.
+	* strncasecmp.c: Include limits.h.
+	(strncasecmp): Avoid integer overflow on exotic platforms.
+	Reported by Paul Eggert.
+
 2005-10-06  Simon Josefsson  <jas@extundo.com>
 
 	* hmac-md5.c: New file.
@@ -2803,7 +2811,7 @@
 
 2004-09-08  Bruno Haible  <bruno@clisp.org>
 
-	* stdint_.h.in: New file, taken from GNU clisp.
+	* stdint_.h: New file, taken from GNU clisp.
 
 2004-09-08  Oskar Liljeblad  <oskar@osk.mine.nu>
 
diff --git a/lib/strcasecmp.c b/lib/strcasecmp.c
--- a/lib/strcasecmp.c
+++ b/lib/strcasecmp.c
@@ -25,6 +25,7 @@
 #include "strcase.h"
 
 #include <ctype.h>
+#include <limits.h>
 
 #if HAVE_MBRTOWC
 # include "mbuiter.h"
@@ -93,6 +94,12 @@
 	}
       while (c1 == c2);
 
-      return c1 - c2;
+      if (UCHAR_MAX <= INT_MAX)
+	return c1 - c2;
+      else
+	/* On machines where 'char' and 'int' are types of the same size, the
+	   difference of two 'unsigned char' values - including the sign bit -
+	   doesn't fit in an 'int'.  */
+	return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
     }
 }
diff --git a/lib/strncasecmp.c b/lib/strncasecmp.c
--- a/lib/strncasecmp.c
+++ b/lib/strncasecmp.c
@@ -1,5 +1,5 @@
 /* strncasecmp.c -- case insensitive string comparator
-   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2005 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -23,6 +23,7 @@
 #include "strcase.h"
 
 #include <ctype.h>
+#include <limits.h>
 
 #define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
 
@@ -54,5 +55,11 @@
     }
   while (c1 == c2);
 
-  return c1 - c2;
+  if (UCHAR_MAX <= INT_MAX)
+    return c1 - c2;
+  else
+    /* On machines where 'char' and 'int' are types of the same size, the
+       difference of two 'unsigned char' values - including the sign bit -
+       doesn't fit in an 'int'.  */
+    return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
 }