[V8] Use Function.name in Error.stack

src/messages.js

Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index b4da5326d661379e389b12f13abc3b4337196642..a8cfb85852628022b1338314d347d58e48d6384c 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -823,8 +823,14 @@ function CallSiteGetFunction() {
 }
 
 function CallSiteGetFunctionName() {
+  // See if the function has displayName
+  var fun = GET_PRIVATE(this, CallSiteFunctionKey);
+  var name = %GetDataProperty(fun, "displayName");
+  if (name && IS_STRING(name)) {

[Yang, 2015/02/12 14:15:29]

I think a single IS_STRING(name) would suffice, as undefined is not a String.

Unless you want to filter out the empty string, since it evaluates to false. In
which case it would be better to explicitly do a string length comparison.

[kozy, 2015/02/12 14:59:57]

Done.

+    return name;
+  }
   // See if the function knows its own name
-  var name = GET_PRIVATE(this, CallSiteFunctionKey).name;
+  name = fun.name;
   if (name) {
     return name;
   }