alloy: mac/linux: Support OS execution via OnProtocolExecution (fixes #1340)

libcef/browser/browser_platform_delegate.cc

@@ -5,12 +5,30 @@
 #include "libcef/browser/browser_platform_delegate.h"
 
 #include "libcef/browser/alloy/alloy_browser_host_impl.h"
+#include "libcef/browser/thread_util.h"
 
 #include "base/logging.h"
+#include "chrome/browser/platform_util.h"
+#include "chrome/browser/shell_integration.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 
+namespace {
+
+void ExecuteExternalProtocol(const GURL& url) {
+  CEF_REQUIRE_BLOCKING();
+
+  // Check that an application is associated with the scheme.
+  if (shell_integration::GetApplicationNameForScheme(url).empty()) {
+    return;
+  }
+
+  CEF_POST_TASK(TID_UI, base::BindOnce(&platform_util::OpenExternal, url));
+}
+
+}  // namespace
+
 CefBrowserPlatformDelegate::CefBrowserPlatformDelegate() = default;
 
 CefBrowserPlatformDelegate::~CefBrowserPlatformDelegate() {
@@ -225,6 +243,11 @@ bool CefBrowserPlatformDelegate::IsNeverComposited(
   return false;
 }
 
+// static
+void CefBrowserPlatformDelegate::HandleExternalProtocol(const GURL& url) {
+  CEF_POST_USER_VISIBLE_TASK(base::BindOnce(ExecuteExternalProtocol, url));
+}
+
 CefEventHandle CefBrowserPlatformDelegate::GetEventHandle(
     const content::NativeWebKeyboardEvent& event) const {
   DCHECK(false);

libcef/browser/native/browser_platform_delegate_native_linux.cc

@@ -233,9 +233,6 @@ bool CefBrowserPlatformDelegateNativeLinux::HandleKeyboardEvent(
   return false;
 }
 
-// static
-void CefBrowserPlatformDelegate::HandleExternalProtocol(const GURL& url) {}
-
 CefEventHandle CefBrowserPlatformDelegateNativeLinux::GetEventHandle(
     const content::NativeWebKeyboardEvent& event) const {
   // TODO(cef): We need to return an XEvent* from this method, but

libcef/browser/native/browser_platform_delegate_native_mac.mm

@@ -462,9 +462,6 @@ bool CefBrowserPlatformDelegateNativeMac::HandleKeyboardEvent(
   return false;
 }
 
-// static
-void CefBrowserPlatformDelegate::HandleExternalProtocol(const GURL& url) {}
-
 CefEventHandle CefBrowserPlatformDelegateNativeMac::GetEventHandle(
     const content::NativeWebKeyboardEvent& event) const {
   return CAST_NSEVENT_TO_CEF_EVENT_HANDLE(event.os_event);

libcef/browser/native/browser_platform_delegate_native_win.cc

@@ -18,7 +18,6 @@
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/win/registry.h"
 #include "base/win/win_util.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "third_party/blink/public/common/input/web_mouse_event.h"
@@ -60,70 +59,6 @@ void WriteTempFileAndView(const std::string& data) {
   ui::win::OpenFileViaShell(tmp_file);
 }
 
-bool HasExternalHandler(const std::string& scheme) {
-  base::win::RegKey key;
-  const std::wstring registry_path =
-      base::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;
-}
-
-// Match the logic in chrome/browser/platform_util_win.cc
-// OpenExternalOnWorkerThread.
-void ExecuteExternalProtocol(const GURL& url) {
-  CEF_REQUIRE_BLOCKING();
-
-  if (!HasExternalHandler(url.scheme())) {
-    return;
-  }
-
-  // Quote the input scheme to be sure that the command does not have
-  // parameters unexpected by the external program. This url should already
-  // have been escaped.
-  std::string escaped_url = url.spec();
-  escaped_url.insert(0, "\"");
-  escaped_url += "\"";
-
-  // 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."
-  //
-  // It may be possible to increase this. https://crbug.com/727909
-  const size_t kMaxUrlLength = 2048;
-  if (escaped_url.length() > kMaxUrlLength) {
-    return;
-  }
-
-  // Specify %windir%\system32 as the CWD so that any new proc spawned does not
-  // inherit this proc's CWD. Without this, uninstalls may be broken by a
-  // long-lived child proc that holds a handle to the browser's version
-  // directory (the browser's CWD). A process's CWD is in the standard list of
-  // directories to search when loading a DLL, and precedes the system directory
-  // when safe DLL search mode is disabled (not the default). Setting the CWD to
-  // the system directory is a nice way to mitigate a potential DLL search order
-  // hijack for processes that don't implement their own mitigation.
-  base::FilePath system_dir;
-  base::PathService::Get(base::DIR_SYSTEM, &system_dir);
-  if (reinterpret_cast<ULONG_PTR>(ShellExecuteA(
-          NULL, "open", escaped_url.c_str(), NULL,
-          system_dir.AsUTF8Unsafe().c_str(), SW_SHOWNORMAL)) <= 32) {
-    // On failure, it may be good to display a message to the user.
-    // https://crbug.com/727913
-    return;
-  }
-}
-
 gfx::Rect GetDisplayWorkAreaNearestPoint(gfx::Point dip_point) {
   const auto display =
       display::Screen::GetScreen()->GetDisplayNearestPoint(dip_point);
@@ -483,11 +418,6 @@ bool CefBrowserPlatformDelegateNativeWin::HandleKeyboardEvent(
   }
 }
 
-// static
-void CefBrowserPlatformDelegate::HandleExternalProtocol(const GURL& url) {
-  CEF_POST_USER_VISIBLE_TASK(base::BindOnce(ExecuteExternalProtocol, url));
-}
-
 CefEventHandle CefBrowserPlatformDelegateNativeWin::GetEventHandle(
     const content::NativeWebKeyboardEvent& event) const {
   if (!event.os_event) {