Version 3.20.11.1

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 911e73b12a5224f861171beb3b7de56255ca2b37..59492e16430432238cc04619af2f11d0be0f49b8 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -2743,7 +2743,8 @@ void MarkCompactCollector::MigrateObject(Address dst,
   if (dest == OLD_POINTER_SPACE) {
     // TODO(hpayer): Replace this check with an assert.
     HeapObject* heap_object = HeapObject::FromAddress(src);
-    CHECK(heap_->TargetSpace(heap_object) == heap_->old_pointer_space());
+    CHECK(heap_object->IsExternalString() ||
+          heap_->TargetSpace(heap_object) == heap_->old_pointer_space());
     Address src_slot = src;
     Address dst_slot = dst;
     ASSERT(IsAligned(size, kPointerSize));