for the CURLDEBUG case, we redefine sprintf and vsprintf to make us notice

if any use of such a function slip through

include/curl/mprintf.h

@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2005, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -42,11 +42,18 @@ CURL_EXTERN char *curl_mvaprintf(const char *format, va_list args);
 #ifdef _MPRINTF_REPLACE
 # define printf curl_mprintf
 # define fprintf curl_mfprintf
+#ifdef CURLDEBUG
+/* When built with CURLDEBUG we define away the sprintf() functions since we
+   don't want internal code to be using them */
+# define sprintf sprintf_was_used
+# define vsprintf vsprintf_was_used
+#else
 # define sprintf curl_msprintf
+# define vsprintf curl_mvsprintf
+#endif
 # define snprintf curl_msnprintf
 # define vprintf curl_mvprintf
 # define vfprintf curl_mvfprintf
-# define vsprintf curl_mvsprintf
 # define vsnprintf curl_mvsnprintf
 # define aprintf curl_maprintf
 # define vaprintf curl_mvaprintf