Correct handling of exceptions occured during getting of exception stack trace.

src/d8.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 // Defined when linking against shared lib on Windows.
 #if defined(USING_V8_SHARED) && !defined(V8_SHARED)
 #define V8_SHARED
 #endif
 
@@ skipping 569 matching lines @@
     } else {
       return String::Concat(
           accumulator, String::NewFromUtf8(isolate, buffer,
                                            String::kNormalString, length - 1));
     }
   }
 }
 
 
 void Shell::Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  Isolate* isolate = args.GetIsolate();
   for (int i = 0; i < args.Length(); i++) {
-    HandleScope handle_scope(args.GetIsolate());
+    HandleScope handle_scope(isolate);
     String::Utf8Value file(args[i]);
     if (*file == NULL) {
-      Throw(args.GetIsolate(), "Error loading file");
+      Throw(isolate, "Error loading file");
       return;
     }
-    Handle<String> source = ReadFile(args.GetIsolate(), *file);
+    Handle<String> source = ReadFile(isolate, *file);
     if (source.IsEmpty()) {
-      Throw(args.GetIsolate(), "Error loading file");
+      Throw(isolate, "Error loading file");
       return;
     }
-    if (!ExecuteString(args.GetIsolate(),
-                       source,
-                       String::NewFromUtf8(args.GetIsolate(), *file),
-                       false,
-                       true)) {
-      Throw(args.GetIsolate(), "Error executing file");
+    if (!ExecuteString(isolate, source, String::NewFromUtf8(isolate, *file),
+                       false, true)) {
+      // Exception is already reported, so clear it before throwing another one.
+      reinterpret_cast<i::Isolate*>(isolate)->clear_pending_exception();

[Yang, 2014/12/23 22:16:09]

Can we assert that there is indeed a pending exception before clearing it?

+      Throw(isolate, "Error executing file");
       return;
     }
   }
 }
 
 
 void Shell::Quit(const v8::FunctionCallbackInfo<v8::Value>& args) {
   int exit_code = args[0]->Int32Value();
   OnExit(args.GetIsolate());
   exit(exit_code);
@@ skipping 1132 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif