Fix deferred load errors / bug #26482

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/become.h"
@@ skipping 10883 matching lines @@
   }
   return Class::null();
 }
 
 
 void LibraryPrefix::set_is_loaded() const {
   StoreNonPointer(&raw_ptr()->is_loaded_, true);
 }
 
 
+bool LibraryPrefix::has_error() const {
+  ASSERT(num_imports() == 1);
+  const Library& deferred_lib = Library::Handle(GetLibrary(0));
+  return deferred_lib.LoadFailed();

[hausner, 2016/06/07 21:47:05]

I'm not sure LoadFailed() is sufficient. You need to check transiently whether
any of the libraries imported by deferred_lib has failed.

+}
+
+
 bool LibraryPrefix::LoadLibrary() const {
   // Non-deferred prefixes are loaded.
   ASSERT(is_deferred_load() || is_loaded());
   if (is_loaded()) {
     return true;  // Load request has already completed.
   }
   ASSERT(is_deferred_load());
   ASSERT(num_imports() == 1);
   if (Dart::snapshot_kind() == Snapshot::kAppNoJIT) {
     // The library list was tree-shaken away.
@@ skipping 11718 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart