Add HandleProtocolExecution event for unregistered protocols (issue #155).

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@163 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/external_protocol_handler_win.cc

@@ -0,0 +1,52 @@
+// Copyright (c) 2011 The Chromium Embedded Framework 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 "external_protocol_handler.h"
+
+#include "base/utf_string_conversions.h"
+#include "base/win/registry.h"
+#include "googleurl/src/gurl.h"
+
+#include <shellapi.h>
+
+namespace ExternalProtocolHandler {
+
+// According to Mozilla in uriloader/exthandler/win/nsOSHelperAppService.cpp:
+// "Some versions of windows (Win2k before SP3, Win XP before SP1) crash in
+// ShellExecute on long URLs (bug 161357 on bugzilla.mozilla.org). IE 5 and 6
+// support URLS of 2083 chars in length, 2K is safe."
+const int kMaxAddressLengthChars = 2048;
+
+bool HasExternalHandler(const std::string& scheme) {
+  base::win::RegKey key;
+  const std::wstring registry_path =
+      ASCIIToWide(scheme + "\\shell\\open\\command");
+  key.Open(HKEY_CLASSES_ROOT, registry_path.c_str(), KEY_READ);
+  if (key.Valid()) {
+    DWORD size = 0;
+    key.ReadValue(NULL, NULL, &size, NULL);
+    if (size > 2) {
+       // ShellExecute crashes the process when the command is empty.
+       // We check for "2" because it always returns the trailing NULL.
+       return true;
+    }
+  }
+
+  return false;
+}
+
+bool HandleExternalProtocol(const GURL& gurl) {
+  if (!HasExternalHandler(gurl.scheme()))
+    return false;
+
+  const std::string& address = gurl.spec();
+  if (address.length() > kMaxAddressLengthChars)
+    return false;
+
+  ShellExecuteA(NULL, "open", address.c_str(), NULL, NULL, SW_SHOWNORMAL);   
+
+  return true;
+}
+
+} // namespace ExternalProtocolHandler