* lread.c (openp): Don't stuff size_t into an 'int'.

Use <= on length, not < on length + 1, to avoid GCC 4.6.0 warning
about possible signed overflow.

2 files changed, 11 insertions, 7 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index d1ab9c4961e..5c6fa587b44 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2011-04-19  Paul Eggert  <eggert@cs.ucla.edu>
 
+        * lread.c (openp): Don't stuff size_t into an 'int'.
+        Use <= on length, not < on length + 1, to avoid GCC 4.6.0 warning
+        about possible signed overflow.
+
         * gtkutil.c: Fix problems found by GCC 4.6.0 on Ubuntu 10.10.
         (GDK_KEY_g): Don't define if already defined.
         (xg_prepare_tooltip): Avoid pointer signedness problem.
diff --git a/src/lread.c b/src/lread.c
index d32f0b6a7e2..2f01b931e61 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -1411,16 +1411,16 @@ int
 openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *storeptr, Lisp_Object predicate)
 {
   register int fd;
-  int fn_size = 100;
+  EMACS_INT fn_size = 100;
   char buf[100];
   register char *fn = buf;
   int absolute = 0;
-  int want_size;
+  EMACS_INT want_length;
   Lisp_Object filename;
   struct stat st;
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5, gcpro6;
   Lisp_Object string, tail, encoded_fn;
-  int max_suffix_len = 0;
+  EMACS_INT max_suffix_len = 0;
 
   CHECK_STRING (str);
 
@@ -1454,11 +1454,11 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *sto
             continue;
         }
 
-      /* Calculate maximum size of any filename made from
+      /* Calculate maximum length of any filename made from
          this path element/specified file name and any possible suffix.  */
-      want_size = max_suffix_len + SBYTES (filename) + 1;
-      if (fn_size < want_size)
-        fn = (char *) alloca (fn_size = 100 + want_size);
+      want_length = max_suffix_len + SBYTES (filename);
+      if (fn_size <= want_length)
+        fn = (char *) alloca (fn_size = 100 + want_length);
 
       /* Loop over suffixes.  */
       for (tail = NILP (suffixes) ? Fcons (empty_unibyte_string, Qnil) : suffixes;