Fix bug 1529: check for NULL handle in v8::TryCatch::StackTrace.

Internal HandleScope::CloseAndEscape crashes on NULL handles.

R=kmillikin@chromium.org
BUG=v8:1529
TEST=mjsunit/regress/regress-1529

Review URL: http://codereview.chromium.org/7309004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8527 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/api.cc

@@ -1682,7 +1682,9 @@ v8::Local<Value> v8::TryCatch::StackTrace() const {
     i::Handle<i::JSObject> obj(i::JSObject::cast(raw_obj), isolate_);
     i::Handle<i::String> name = isolate_->factory()->LookupAsciiSymbol("stack");
     if (!obj->HasProperty(*name)) return v8::Local<Value>();
-    return v8::Utils::ToLocal(scope.CloseAndEscape(i::GetProperty(obj, name)));
+    i::Handle<i::Object> value = i::GetProperty(obj, name);
+    if (value.is_null()) return v8::Local<Value>();
+    return v8::Utils::ToLocal(scope.CloseAndEscape(value));
   } else {
     return v8::Local<Value>();
   }

test/mjsunit/regress/regress-1529.js

+// Copyright 2011 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// See: http://code.google.com/p/v8/issues/detail?id=1529
+
+try {
+  Error.prepareStackTrace = function (error, stackTrace) {
+    stackTrace.some();
+  };
+  x;
+} catch (e) {}