If an external string enters the symbol table, make sure to set the...

src/runtime.cc

Index: src/runtime.cc
===================================================================
--- src/runtime.cc	(revision 1724)
+++ src/runtime.cc	(working copy)
@@ -6525,9 +6525,9 @@
     return true;
   }
   if (StringShape(String::cast(str)).IsAsciiRepresentation()) {
-    return ExternalAsciiString::cast(str)->resource() != 0;
+    return ExternalAsciiString::cast(str)->resource() != NULL;
   } else if (StringShape(String::cast(str)).IsTwoByteRepresentation()) {
-    return ExternalTwoByteString::cast(str)->resource() != 0;
+    return ExternalTwoByteString::cast(str)->resource() != NULL;
   } else {
     return true;
   }