Fix issue 294 by ensuring that we don't lose the copy flag on memory

frame elements when allocating them to a register as a result of
popping one of their copies.
Review URL: http://codereview.chromium.org/57053

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1655 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/virtual-frame-ia32.cc

@@ -979,6 +979,8 @@ Result VirtualFrame::Pop() {
     Use(temp.reg(), index);
     FrameElement new_element =
         FrameElement::RegisterElement(temp.reg(), FrameElement::SYNCED);
+    // Preserve the copy flag on the element.
+    if (element.is_copied()) new_element.set_copied();
     elements_[index] = new_element;
     __ mov(temp.reg(), Operand(ebp, fp_relative(index)));
     return Result(temp.reg(), cgen_);

test/mjsunit/regress/regress-294.js

+// Copyright 2009 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.
+
+// Should not crash.
+// See http://code.google.com/p/v8/issues/detail?id=294
+
+function f() { return false; }
+
+function test(x) {
+  var y = x;
+  if (x == "kat") x = "kat";
+  else {
+    x = "hund";
+    var z = f();
+    if (!z) x = "kat";
+  }
+}
+
+test("hund");