std_sstream.h (setbuf): Check __n >= 0.

2003-06-18  Paolo Carlini  <pcarlini@unitus.it>
	    Benjamin Kosnik  <bkoz@redhat.com>

	* include/std/std_sstream.h (setbuf): Check __n >= 0.
	* include/bits/fstream.tcc (setbuf): Tweak.

Co-Authored-By: Benjamin Kosnik <bkoz@redhat.com>

From-SVN: r68163

libstdc++-v3/ChangeLog

 2003-06-18  Paolo Carlini  <pcarlini@unitus.it>
+            Benjamin Kosnik  <bkoz@redhat.com>
+
+	* include/std/std_sstream.h (setbuf): Check __n >= 0.
+	* include/bits/fstream.tcc (setbuf): Tweak.
+
+2003-06-18  Paolo Carlini  <pcarlini@unitus.it>
 
 	* include/bits/sstream.tcc (seekoff): We can't seek beyond
 	_M_out_lim, therefore _M_move_out_cur boils down to simply

libstdc++-v3/include/bits/fstream.tcc

@@ -429,7 +429,7 @@ namespace std
     {
       if (!this->is_open() && __s == 0 && __n == 0)
 	this->_M_buf_size = 1;
-      else if (__s && __n >= 1)
+      else if (__s && __n > 0)
 	{
 	  // This is implementation-defined behavior, and assumes that
 	  // an external char_type array of length __n exists and has

libstdc++-v3/include/std/std_sstream.h

@@ -208,12 +208,12 @@ namespace std
       virtual __streambuf_type*
       setbuf(char_type* __s, streamsize __n)
       {
-	if (__s && __n)
+	if (__s && __n >= 0)
 	  {
 	    // This is implementation-defined behavior, and assumes
-	    // that an external char_type array of length (__s + __n)
-	    // exists and has been pre-allocated. If this is not the
-	    // case, things will quickly blow up.
+	    // that an external char_type array of length __n exists
+	    // and has been pre-allocated. If this is not the case,
+	    // things will quickly blow up.
 	    
 	    // Step 1: Destroy the current internal array.
 	    _M_string = __string_type(__s, __n);