update from texinfo

[gnulib.git] / lib / vsnprintf.c

diff --git a/lib/vsnprintf.c b/lib/vsnprintf.c
index f35aee4..f9b7d5d 100644 (file)
--- a/lib/vsnprintf.c
+++ b/lib/vsnprintf.c
@@ -1,5 +1,5 @@
 /* Formatted output to strings.
-   Copyright (C) 2004 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2006-2014 Free Software Foundation, Inc.
    Written by Simon Josefsson and Yoann Vandoorselaere <yoann@prelude-ids.org>.
 
    This program is free software; you can redistribute it and/or modify
@@ -13,18 +13,18 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License along
-   with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   with this program; if not, see <http://www.gnu.org/licenses/>.  */
 
 #ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
 
 /* Specification.  */
-#include "vsnprintf.h"
+#include <stdio.h>
 
+#include <errno.h>
+#include <limits.h>
 #include <stdarg.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -34,25 +34,37 @@
    additional length SIZE limit how much is written into STR.  Returns
    string length of formatted string (which may be larger than SIZE).
    STR may be NULL, in which case nothing will be written.  On error,
-   return a negative value. */
+   return a negative value.  */
 int
 vsnprintf (char *str, size_t size, const char *format, va_list args)
 {
   char *output;
   size_t len;
+  size_t lenbuf = size;
 
-  len = size;
-  output = vasnprintf (str, &len, format, args);
+  output = vasnprintf (str, &lenbuf, format, args);
+  len = lenbuf;
 
   if (!output)
     return -1;
 
-  if (str != NULL)
-    if (len > size - 1) /* equivalent to: (size > 0 && len >= size) */
-      str[size - 1] = '\0';
-
   if (output != str)
-    free (output);
+    {
+      if (size)
+        {
+          size_t pruned_len = (len < size ? len : size - 1);
+          memcpy (str, output, pruned_len);
+          str[pruned_len] = '\0';
+        }
+
+      free (output);
+    }
+
+  if (len > INT_MAX)
+    {
+      errno = EOVERFLOW;
+      return -1;
+    }
 
   return len;
 }