Undisable HostResolverImplTest.EmptyHost, by making empty host fail to resolv...

net/base/host_resolver_proc.cc

 // Copyright (c) 2006-2008 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/base/host_resolver_proc.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <ws2tcpip.h>
@@ skipping 107 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(DnsReloadTimer);
 };
 
 // A TLS slot to the TimeTicks for the current thread.
 // static
 ThreadLocalStorage::Slot DnsReloadTimer::tls_index_(base::LINKER_INITIALIZED);
 
 #endif  // defined(OS_LINUX)
 
 int SystemHostResolverProc(const std::string& host, AddressList* addrlist) {
+  // The result of |getaddrinfo| for empty hosts is inconsistent across systems.
+  // On Windows it gives the default interface's address, whereas on Linux it
+  // gives an error. We will make it fail on all platforms for consistency.
+  if (host.empty())
+    return ERR_NAME_NOT_RESOLVED;
+
   struct addrinfo* ai = NULL;
   struct addrinfo hints = {0};
   hints.ai_family = AF_UNSPEC;
 
 #if defined(OS_WIN)
   // DO NOT USE AI_ADDRCONFIG ON WINDOWS.
   //
   // The following comment in <winsock2.h> is the best documentation I found
   // on AI_ADDRCONFIG for Windows:
   //   Flags used in "hints" argument to getaddrinfo()
@@ skipping 33 matching lines @@
 #endif
 
   if (err)
     return ERR_NAME_NOT_RESOLVED;
 
   addrlist->Adopt(ai);
   return OK;
 }
 
 }  // namespace net