Hpack fuzzing tweaks to address CHECK failures on ClusterFuzz

net/spdy/hpack_decoder.cc

 // Copyright 2014 The Chromium 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 "net/spdy/hpack_decoder.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "net/spdy/hpack_constants.h"
@@ skipping 30 matching lines @@
   headers_block_buffer_.insert(headers_block_buffer_.end(),
                                headers_data,
                                headers_data + headers_data_length);
   return true;
 }
 
 bool HpackDecoder::HandleControlFrameHeadersComplete(SpdyStreamId id) {
   HpackInputStream input_stream(max_string_literal_size_,
                                 headers_block_buffer_);
   while (input_stream.HasMoreData()) {
-    if (!DecodeNextOpcode(&input_stream))
+    if (!DecodeNextOpcode(&input_stream)) {
+      headers_block_buffer_.clear();
       return false;
+    }
   }
   headers_block_buffer_.clear();
 
   // Emit everything in the reference set that hasn't already been emitted.
   // Also clear entry state for the next decoded headers block.
   // TODO(jgraettinger): We may need to revisit the order in which headers
   // are emitted (b/14051713).
   for (HpackEntry::OrderedSet::const_iterator it =
           header_table_.reference_set().begin();
        it != header_table_.reference_set().end(); ++it) {
@@ skipping 168 matching lines @@
     return result;
   } else if (input_stream->MatchPrefixAndConsume(
       kStringLiteralIdentityEncoded)) {
     return input_stream->DecodeNextIdentityString(output);
   } else {
     return false;
   }
 }
 
 }  // namespace net