Bug 431950 - disable scary-but-harmless zlib trace warnings in debug builds. r=bholley

modules/zlib/src/ChangeLog.moz

@@ -39,3 +39,6 @@ Mozilla.org changes:
 
 - 24 July 2005
   Updated zlib.def with new symbols in zlib version 1.2.3
+
+- 13 September 2009
+  Don't enable zlib's debug output when the Mozilla build is in debug mode (bug 431950)

modules/zlib/src/zutil.h

@@ -238,6 +238,11 @@ extern const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
    extern void zmemzero OF((Bytef* dest, uInt len));
 #endif
 
+/* Ignore the Mozilla build env's DEBUG unless ZLIB_DEBUG is also set */
+#ifndef ZLIB_DEBUG
+#undef DEBUG
+#endif
+
 /* Diagnostic functions */
 #ifdef DEBUG
 #  include <stdio.h>