Add asserts to verify handle is always non null and the kIDENT literal

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 7393 matching lines @@
       token_obj_(Object::Handle()),
       literal_token_(LiteralToken::Handle()),
       literal_str_(String::Handle()) {
     token_objects_.Add(Object::null_string());
   }
   ~CompressedTokenStreamData() {
   }
 
   // Add an IDENT token into the stream and the token objects array.
   void AddIdentToken(const String* ident) {
-    if (ident != NULL) {
-      // If the IDENT token is already in the tokens object array use the
-      // same index instead of duplicating it.
-      intptr_t index = FindIdentIndex(ident);
-      if (index == -1) {
-        WriteIndex(token_objects_.Length());
-        ASSERT(ident != NULL);
-        token_objects_.Add(*ident);
-      } else {
-        WriteIndex(index);
-      }
+    ASSERT(ident != NULL);
+    ASSERT(ident->IsSymbol());
+    // If the IDENT token is already in the tokens object array use the
+    // same index instead of duplicating it.
+    intptr_t index = FindIdentIndex(ident);
+    if (index == -1) {
+      WriteIndex(token_objects_.Length());
+      ASSERT(ident != NULL);
+      token_objects_.Add(*ident);
     } else {
-      WriteIndex(0);
+      WriteIndex(index);
     }
   }
 
   // Add a LITERAL token into the stream and the token objects array.
   void AddLiteralToken(Token::Kind kind, const String* literal) {
     if (literal != NULL) {
       // If the literal token is already in the tokens object array use the
       // same index instead of duplicating it.
       intptr_t index = FindLiteralIndex(kind, literal);
       if (index == -1) {
@@ skipping 11421 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart