Prevent read-after-buffer in SourcePositionTableIterator::Advance.

src/source-position-table.cc

 // Copyright 2016 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/source-position-table.h"
 
 #include "src/log.h"
 #include "src/objects-inl.h"
 #include "src/objects.h"
 
@@ skipping 157 matching lines @@
 }
 
 SourcePositionTableIterator::SourcePositionTableIterator(ByteArray* byte_array)
     : table_(byte_array), index_(0), current_() {
   Advance();
 }
 
 void SourcePositionTableIterator::Advance() {
   DCHECK(!done());
   DCHECK(index_ >= 0 && index_ <= table_->length());
-  if (index_ == table_->length()) {
+  if (index_ >= table_->length()) {
     index_ = kDone;
   } else {
     PositionTableEntry tmp;
     DecodeEntry(table_, &index_, &tmp);
     AddAndSetEntry(current_, tmp);
   }
 }
 
 }  // namespace internal
 }  // namespace v8