Flatten strings before internalization

src/objects.cc

 // Copyright 2015 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.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 17069 matching lines @@
 bool SeqOneByteSubStringKey::IsMatch(Object* string) {
   Vector<const uint8_t> chars(string_->GetChars() + from_, length_);
   return String::cast(string)->IsOneByteEqualTo(chars);
 }
 
 
 // InternalizedStringKey carries a string/internalized-string object as key.
 class InternalizedStringKey : public HashTableKey {
  public:
   explicit InternalizedStringKey(Handle<String> string)
-      : string_(string) { }
+      : string_(String::Flatten(string)) {}
 
   bool IsMatch(Object* string) override {
     return String::cast(string)->Equals(*string_);
   }
 
   uint32_t Hash() override { return string_->Hash(); }
 
   uint32_t HashForObject(Object* other) override {
     return String::cast(other)->Hash();
   }
@@ skipping 841 matching lines @@
     DCHECK(StringShape(*result).IsInternalized());
     return result;
   }
 }
 
 
 void StringTable::EnsureCapacityForDeserialization(Isolate* isolate,
                                                    int expected) {
   Handle<StringTable> table = isolate->factory()->string_table();
   // We need a key instance for the virtual hash function.
-  InternalizedStringKey dummy_key(Handle<String>::null());
+  InternalizedStringKey dummy_key(isolate->factory()->empty_string());
   table = StringTable::EnsureCapacity(table, expected, &dummy_key);
   isolate->heap()->SetRootStringTable(*table);
 }
 
 
 Handle<String> StringTable::LookupString(Isolate* isolate,
                                          Handle<String> string) {
   InternalizedStringKey key(string);
   return LookupKey(isolate, &key);
 }
@@ skipping 1865 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8