quic_client should check return codes when parsing command-line flags.

net/tools/quic/quic_client_bin.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.
 
 // A binary wrapper for QuicClient.
 // Connects to a host using QUIC, sends a request to the provided URL, and
 // displays the response.
 //
 // Some usage examples:
 //
@@ skipping 110 matching lines @@
     cout << help_str;
     exit(0);
   }
   if (line->HasSwitch("host")) {
     FLAGS_host = line->GetSwitchValueASCII("host");
   }
   if (line->HasSwitch("port")) {
     int port;
     if (base::StringToInt(line->GetSwitchValueASCII("port"), &port)) {
       FLAGS_port = port;
+    } else {
+      std::cerr << "--port must be an integer\n";
+      return 1;

[Ryan Hamilton, 2015/02/18 23:51:13]

Early return please:

if (!base::StringToInt()) {
  std::cerr <<;
  return 1;
}
FLAGS_port = port;

[dougk, 2015/02/19 00:29:19]

Done.

     }
   }
   if (line->HasSwitch("body")) {
     FLAGS_body = line->GetSwitchValueASCII("body");
   }
   if (line->HasSwitch("headers")) {
     FLAGS_headers = line->GetSwitchValueASCII("headers");
   }
   if (line->HasSwitch("quiet")) {
     FLAGS_quiet = true;
@@ skipping 22 matching lines @@
   base::AtExitManager exit_manager;
 
   // Determine IP address to connect to from supplied hostname.
   net::IPAddressNumber ip_addr;
 
   // TODO(rtenneti): GURL's doesn't support default_protocol argument, thus
   // protocol is required in the URL.
   GURL url(urls[0]);
   string host = FLAGS_host;
   // TODO(rtenneti): get ip_addr from hostname by doing host resolution.
-  CHECK(!host.empty());
-  net::ParseIPLiteralToNumber(host, &ip_addr);
+  if (host.empty()) {
+    LOG(ERROR) << "--host must be specified\n";
+    return 1;
+  }
+  if (!net::ParseIPLiteralToNumber(host, &ip_addr)) {
+    LOG(ERROR) << "--host could not be parsed as an IP address\n";
+    return 1;
+  }
 
   string host_port = net::IPAddressToStringWithPort(ip_addr, FLAGS_port);
   VLOG(1) << "Resolved " << host << " to " << host_port << endl;
 
   // Build the client, and try to connect.
   bool is_https = (FLAGS_port == 443);
   net::EpollServer epoll_server;
   net::QuicServerId server_id(host, FLAGS_port, is_https,
                               net::PRIVACY_MODE_DISABLED);
   net::QuicVersionVector versions = net::QuicSupportedVersions();
@@ skipping 86 matching lines @@
       return 0;
     } else {
       cout << "Request failed (redirect " << response_code << ")." << endl;
       return 1;
     }
   } else {
     cerr << "Request failed (" << response_code << ")." << endl;
     return 1;
   }
 }