Initialize buffer in test before adding it to a packet

net/quic/core/quic_packet_generator_test.cc

 // Copyright (c) 2012 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/quic/core/quic_packet_generator.h"
 
 #include <cstdint>
 #include <memory>
 #include <string>
 
@@ skipping 834 matching lines @@
   EXPECT_QUIC_BUG(generator_.FinishBatchOperations(),
                   "packet_number_length 1 is too small "
                   "for least_unacked_delta: 1001");
 }
 
 // Regression test for b/31486443.
 TEST_F(QuicPacketGeneratorTest, ConnectionCloseFrameLargerThanPacketSize) {
   delegate_.SetCanWriteAnything();
   QuicConnectionCloseFrame* frame = new QuicConnectionCloseFrame();
   frame->error_code = QUIC_PACKET_WRITE_ERROR;
-  char buf[2000];
+  char buf[2000] = {};
   QuicStringPiece error_details(buf, 2000);
   frame->error_details = error_details.as_string();
   EXPECT_CALL(delegate_,
               OnUnrecoverableError(QUIC_FAILED_TO_SERIALIZE_PACKET,
                                    "Single frame cannot fit into a packet", _));
   EXPECT_QUIC_BUG(generator_.AddControlFrame(QuicFrame(frame)), "");
   EXPECT_TRUE(generator_.HasQueuedFrames());
 }
 
 }  // namespace test
 }  // namespace net