Avoid access violations, passing NULL to printf( "...%s..." ).

2 files changed, 15 insertions, 2 deletions

diff --git a/winsup/mingw/ChangeLog b/winsup/mingw/ChangeLog
index dcc57c62a..0d6c2f677 100644
--- a/winsup/mingw/ChangeLog
+++ b/winsup/mingw/ChangeLog
@@ -1,3 +1,12 @@
+2008-08-27  Keith Marshall  <keithmarshall@users.sourceforge.net>
+
+	Avoid access violations, passing NULL to printf( "...%s..." );
+	(inconsistencency with MSVCRT and glibc, reported by Colin Harrison).
+
+	* mingwex/stdio/pformat.c (__pformat_puts): Substitute "(null)"
+	for argument value, if caller passes a NULL pointer.
+	(__pformat_wcputs): Likewise, substitute L"(null)".
+
 2008-08-14  Keith Marshall  <keithmarshall@users.sourceforge.net>
 
 	Add missing dependencies for building libmingwex.a.
diff --git a/winsup/mingw/mingwex/stdio/pformat.c b/winsup/mingw/mingwex/stdio/pformat.c
index 82dbcd741..2e2411606 100644
--- a/winsup/mingw/mingwex/stdio/pformat.c
+++ b/winsup/mingw/mingwex/stdio/pformat.c
@@ -356,8 +356,10 @@ void __pformat_puts( const char *s, __pformat_t *stream )
    * to the `__pformat()' output stream.
    *
    * This is implemented as a trivial call to `__pformat_putchars()',
-   * passing the length of the input string as the character count.
+   * passing the length of the input string as the character count,
+   * (after first verifying that the input pointer is not NULL).
    */
+  if( s == NULL ) s = "(null)";
   __pformat_putchars( s, strlen( s ), stream );
 }
 
@@ -434,8 +436,10 @@ void __pformat_wcputs( const wchar_t *s, __pformat_t *stream )
    * the input string, to the `__pformat()' output stream.
    *
    * This is implemented as a trivial call to `__pformat_wputchars()',
-   * passing the length of the input string as the character count.
+   * passing the length of the input string as the character count,
+   * (after first verifying that the input pointer is not NULL).
    */
+  if( s == NULL ) s = L"(null)";
   __pformat_wputchars( s, wcslen( s ), stream );
 }