- Avoid rewrapping LoadError inside LoadError.

runtime/bin/builtin.dart

Index: runtime/bin/builtin.dart
===================================================================
--- runtime/bin/builtin.dart	(revision 44402)
+++ runtime/bin/builtin.dart	(working copy)
@@ -274,7 +274,7 @@
   _finishedOneLoadRequest(uri);
 }
 
-void _asyncLoadError(tag, uri, libraryUri, error) {
+void _asyncLoadError(int tag, String uri, String libraryUri, LoadError error) {
   if (_logBuiltin) {
     _print("_asyncLoadError($uri), error: $error");
   }
@@ -283,7 +283,7 @@
     // uri.
     libraryUri = uri;
   }
-  _asyncLoadErrorCallback(uri, libraryUri, new LoadError(error.toString()));
+  _asyncLoadErrorCallback(uri, libraryUri, error);
   _finishedOneLoadRequest(uri);
 }
 
@@ -297,10 +297,15 @@
     if (dataOrError is List<int>) {
       _loadScript(tag, uri, libraryUri, dataOrError);
     } else {
-      _asyncLoadError(tag, uri, libraryUri, dataOrError);
+      assert(dataOrError is String);
+      var error = new LoadError(dataOrError.toString());

[rmacnak, 2015/03/11 23:50:52]

toString is redundant

[Ivan Posva, 2015/03/11 23:53:57]

Redundant, but defensive in case you are not running in checked mode. I will
leave it like this and I hope that in a good round of cleanup we can get rid of
this. Either the requirement that we get a String in the error case or the call
toString().

+      _asyncLoadError(tag, uri, libraryUri, error);
     }
   }).catchError((e) {
-    _asyncLoadError(tag, uri, libraryUri, e.toString());
+    // Wrap inside a LoadError unless we are already propagating a previously
+    // seen LoadError.
+    var error = (e is LoadError) ? e : new LoadError(e.toString);
+    _asyncLoadError(tag, uri, libraryUri, error);
   });
 
   try {
@@ -311,7 +316,10 @@
     if (_logBuiltin) {
       _print("Exception when communicating with service isolate: $e");
     }
-    _asyncLoadError(tag, uri, libraryUri, e.toString());
+    // Wrap inside a LoadError unless we are already propagating a previously
+    // seen LoadError.
+    var error = (e is LoadError) ? e : new LoadError(e.toString);
+    _asyncLoadError(tag, uri, libraryUri, error);
     receivePort.close();
   }
 }