From: Bruno Haible <bruno@clisp.org>
Date: Thu, 7 Oct 2004 16:15:22 +0000 (+0000)
Subject: Avoid a memory allocation when possible.
X-Git-Tag: cvs-readonly~3853
X-Git-Url: http://erislabs.net/gitweb/?a=commitdiff_plain;h=f5200a50fa42fdaed40ecc67b27f41be328a6a01;p=gnulib.git

Avoid a memory allocation when possible.
---

diff --git a/lib/ChangeLog b/lib/ChangeLog
index 1c3510dbd..08659a34d 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,8 @@
+2004-10-07  Bruno Haible  <bruno@clisp.org>
+
+	* snprintf.c (snprintf): Avoid a memory allocation if the result fits
+	into the provided buffer.
+
 2004-10-06  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* diacrit.c, diacrit.h: Add GPL notice.
diff --git a/lib/snprintf.c b/lib/snprintf.c
index 667ed9462..9a4edc1f5 100644
--- a/lib/snprintf.c
+++ b/lib/snprintf.c
@@ -42,19 +42,19 @@ snprintf (char *str, size_t size, const char *format, ...)
   va_list args;
 
   va_start (args, format);
-  output = vasnprintf (NULL, &len, format, args);
+  len = size;
+  output = vasnprintf (str, &len, format, args);
   va_end (args);
 
   if (!output)
     return -1;
 
-  if (str && size > 0)
-    {
-      memcpy (str, output, MIN (len + 1, size));
+  if (str != NULL)
+    if (len > size - 1) /* equivalent to: (size > 0 && len >= size) */
       str[size - 1] = '\0';
-    }
 
-  free (output);
+  if (output != str)
+    free (output);
 
   return len;
 }