Fast-fail WPAD detection.

net/dns/mock_host_resolver.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/dns/mock_host_resolver.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 329 matching lines @@
 int RuleBasedHostResolverProc::Resolve(const std::string& host,
                                        AddressFamily address_family,
                                        HostResolverFlags host_resolver_flags,
                                        AddressList* addrlist,
                                        int* os_error) {
   RuleList::iterator r;
   for (r = rules_.begin(); r != rules_.end(); ++r) {
     bool matches_address_family =
         r->address_family == ADDRESS_FAMILY_UNSPECIFIED ||
         r->address_family == address_family;
+    // Ignore HOST_RESOLVER_SYSTEM_ONLY, since it should have no impact on
+    // whether a rule matches.
+    HostResolverFlags flags = host_resolver_flags & ~HOST_RESOLVER_SYSTEM_ONLY;
     // Flags match if all of the bitflags in host_resolver_flags are enabled
     // in the rule's host_resolver_flags. However, the rule may have additional
     // flags specified, in which case the flags should still be considered a
     // match.
-    bool matches_flags = (r->host_resolver_flags & host_resolver_flags) ==
-        host_resolver_flags;
+    bool matches_flags = (r->host_resolver_flags & flags) == flags;
     if (matches_flags && matches_address_family &&
         MatchPattern(host, r->host_pattern)) {
       if (r->latency_ms != 0) {
         base::PlatformThread::Sleep(
             base::TimeDelta::FromMilliseconds(r->latency_ms));
       }
 
       // Remap to a new host.
       const std::string& effective_host =
           r->replacement.empty() ? host : r->replacement;
@@ skipping 68 matching lines @@
   CHECK_EQ(old_proc, current_proc_);
 }
 
 void ScopedDefaultHostResolverProc::Init(HostResolverProc* proc) {
   current_proc_ = proc;
   previous_proc_ = HostResolverProc::SetDefault(current_proc_.get());
   current_proc_->SetLastProc(previous_proc_.get());
 }
 
 }  // namespace net