Move header-ordering validation from hpack decoder to header validator.

net/spdy/header_coalescer.cc

 // Copyright (c) 2016 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/header_coalescer.h"
 
 #include "base/strings/string_util.h"
 
 namespace net {
 
 void HeaderCoalescer::OnHeader(base::StringPiece key, base::StringPiece value) {

[Bence, 2016/06/20 12:11:27]

Please return if |error_seen_| first thing in this function: there is no point
in doing any more work.

   if (key.empty()) {
     DVLOG(1) << "Header name must not be empty.";
     error_seen_ = true;
     return;
   }
 
+  if (key[0] == ':') {
+    if (regular_header_seen_) {
+      error_seen_ = true;
+      return;
+    }
+  } else {
+    regular_header_seen_ = true;
+  }
+
   auto iter = headers_.find(key);
   if (iter == headers_.end()) {
     headers_[key] = value;
   } else {
     // This header had multiple values, so it must be reconstructed.
     base::StringPiece v = iter->second;
     std::string s(v.data(), v.length());
     if (key == "cookie") {
       // Obeys section 8.1.2.5 in RFC 7540 for cookie reconstruction.
       s.append("; ");
     } else {
       base::StringPiece("\0", 1).AppendToString(&s);
     }
     value.AppendToString(&s);
     headers_.ReplaceOrAppendHeader(key, s);
   }
 }
 
 }  // namespace net