Fix possible crash in FixedDoubleArray::Initialize()

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 3b0e96f1ef93793398b98eb7a5daa50ca1c156a6..02f56ce1ae2aee7bf280284c5cddb17112573e28 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1749,9 +1749,17 @@ bool FixedDoubleArray::is_the_hole(int index) {
 void FixedDoubleArray::Initialize(FixedDoubleArray* from) {
   int old_length = from->length();
   ASSERT(old_length < length());
-  OS::MemCopy(FIELD_ADDR(this, kHeaderSize),
-              FIELD_ADDR(from, kHeaderSize),
-              old_length * kDoubleSize);
+  if (old_length * kDoubleSize >= OS::kMinComplexMemCopy) {
+    OS::MemCopy(FIELD_ADDR(this, kHeaderSize),
+                FIELD_ADDR(from, kHeaderSize),
+                old_length * kDoubleSize);
+  } else {
+    int offset = kHeaderSize;
+    for (int i = 0; i < old_length; ++i) {
+      WRITE_DOUBLE_FIELD(this, offset, READ_DOUBLE_FIELD(from, offset));
+      offset += kDoubleSize;
+    }
+  }
   int offset = kHeaderSize + old_length * kDoubleSize;
   for (int current = from->length(); current < length(); ++current) {
     WRITE_DOUBLE_FIELD(this, offset, hole_nan_as_double());

[danno, 2011/09/06 13:22:13]

just do set(current, from->get(current)) and don't track offset.

[Jakob Kummerow, 2011/09/06 13:31:03]

Done.