Index: /trunk/src/libs/xpcom18a4/xpcom/base/nscore.h
===================================================================
--- /trunk/src/libs/xpcom18a4/xpcom/base/nscore.h	(revision 27470)
+++ /trunk/src/libs/xpcom18a4/xpcom/base/nscore.h	(revision 27471)
@@ -459,6 +459,6 @@
 
 #if defined(__GNUC__) && (__GNUC__ > 2)
-#define NS_LIKELY(x)    (__builtin_expect((x), 1))
-#define NS_UNLIKELY(x)  (__builtin_expect((x), 0))
+#define NS_LIKELY(x)    (__builtin_expect(!!(x), 1))
+#define NS_UNLIKELY(x)  (__builtin_expect(!!(x), 0))
 #else
 #define NS_LIKELY(x)    (x)