[v2, windows] Load WebView2 loader from embedded only (#1432)

v2/internal/frontend/desktop/windows/go-webview2/webviewloader/module.go

@@ -10,11 +10,6 @@ import (
 )
 
 var (
-	nativeModule                                       = windows.NewLazyDLL("WebView2Loader")
-	nativeCreate                                       = nativeModule.NewProc("CreateCoreWebView2EnvironmentWithOptions")
-	nativeCompareBrowserVersions                       = nativeModule.NewProc("CompareBrowserVersions")
-	nativeGetAvailableCoreWebView2BrowserVersionString = nativeModule.NewProc("GetAvailableCoreWebView2BrowserVersionString")
-
 	memOnce                                         sync.Once
 	memModule                                       winloader.Module
 	memCreate                                       winloader.Proc
@@ -23,6 +18,11 @@ var (
 	memErr                                          error
 )
 
+const (
+	// https://referencesource.microsoft.com/#system.web/Util/hresults.cs,20
+	E_FILENOTFOUND = 0x80070002
+)
+
 // CompareBrowserVersions will compare the 2 given versions and return:
 //  -1 = v1 < v2
 //   0 = v1 == v2
@@ -38,26 +38,17 @@ func CompareBrowserVersions(v1 string, v2 string) (int, error) {
 		return 0, err
 	}
 
-	nativeErr := nativeModule.Load()
+	err = loadFromMemory()
-	if nativeErr == nil {
-		nativeErr = nativeCompareBrowserVersions.Find()
-	}
-	var result int
-	if nativeErr != nil {
-		err := loadFromMemory(nativeErr)
 	if err != nil {
-			return 0, fmt.Errorf("Unable to load WebView2Loader.dll from disk: %v -- or from memory: %w", nativeErr, memErr)
+		return 0, err
 	}
+
+	var result int
 	_, _, err = memCompareBrowserVersions.Call(
 		uint64(uintptr(unsafe.Pointer(_v1))),
 		uint64(uintptr(unsafe.Pointer(_v2))),
 		uint64(uintptr(unsafe.Pointer(&result))))
-	} else {
+
-		_, _, err = nativeCompareBrowserVersions.Call(
-			uintptr(unsafe.Pointer(_v1)),
-			uintptr(unsafe.Pointer(_v2)),
-			uintptr(unsafe.Pointer(&result)))
-	}
 	if err != windows.ERROR_SUCCESS {
 		return result, err
 	}
@@ -67,28 +58,25 @@ func CompareBrowserVersions(v1 string, v2 string) (int, error) {
 // GetInstalledVersion returns the installed version of the webview2 runtime.
 // If there is no version installed, a blank string is returned.
 func GetInstalledVersion() (string, error) {
-	nativeErr := nativeModule.Load()
+	err := loadFromMemory()
-	if nativeErr == nil {
-		nativeErr = nativeGetAvailableCoreWebView2BrowserVersionString.Find()
-	}
-	var err error
-	var result *uint16
-	if nativeErr != nil {
-		err := loadFromMemory(nativeErr)
-		if err != nil {
-			return "", fmt.Errorf("Unable to load WebView2Loader.dll from disk: %v -- or from memory: %w", nativeErr, memErr)
-		}
-		_, _, err = memGetAvailableCoreWebView2BrowserVersionString.Call(
-			uint64(uintptr(unsafe.Pointer(nil))),
-			uint64(uintptr(unsafe.Pointer(&result))))
-	} else {
-		_, _, err = nativeCompareBrowserVersions.Call(
-			uintptr(unsafe.Pointer(nil)),
-			uintptr(unsafe.Pointer(&result)))
-	}
 	if err != nil {
 		return "", err
 	}
+
+	var result *uint16
+	res, _, err := memGetAvailableCoreWebView2BrowserVersionString.Call(
+		uint64(uintptr(unsafe.Pointer(nil))),
+		uint64(uintptr(unsafe.Pointer(&result))))
+
+	if res != 0 {
+		if res == E_FILENOTFOUND {
+			// Webview2 is not installed
+			return "", nil
+		}
+
+		return "", fmt.Errorf("Unable to call GetAvailableCoreWebView2BrowserVersionString (%x): %w", res, err)
+	}
+
 	version := windows.UTF16PtrToString(result)
 	windows.CoTaskMemFree(unsafe.Pointer(result))
 	return version, nil
@@ -97,12 +85,7 @@ func GetInstalledVersion() (string, error) {
 // CreateCoreWebView2EnvironmentWithOptions tries to load WebviewLoader2 and
 // call the CreateCoreWebView2EnvironmentWithOptions routine.
 func CreateCoreWebView2EnvironmentWithOptions(browserExecutableFolder, userDataFolder *uint16, environmentOptions uintptr, environmentCompletedHandle uintptr) (uintptr, error) {
-	nativeErr := nativeModule.Load()
+	err := loadFromMemory()
-	if nativeErr == nil {
-		nativeErr = nativeCreate.Find()
-	}
-	if nativeErr != nil {
-		err := loadFromMemory(nativeErr)
 	if err != nil {
 		return 0, err
 	}
@@ -113,23 +96,15 @@ func CreateCoreWebView2EnvironmentWithOptions(browserExecutableFolder, userDataF
 		uint64(environmentCompletedHandle),
 	)
 	return uintptr(res), nil
-	}
-	res, _, _ := nativeCreate.Call(
-		uintptr(unsafe.Pointer(browserExecutableFolder)),
-		uintptr(unsafe.Pointer(userDataFolder)),
-		environmentOptions,
-		environmentCompletedHandle,
-	)
-	return res, nil
 }
 
-func loadFromMemory(nativeErr error) error {
+func loadFromMemory() error {
 	var err error
 	// DLL is not available natively. Try loading embedded copy.
 	memOnce.Do(func() {
 		memModule, memErr = winloader.LoadFromMemory(WebView2Loader)
 		if memErr != nil {
-			err = fmt.Errorf("Unable to load WebView2Loader.dll from disk: %v -- or from memory: %w", nativeErr, memErr)
+			err = fmt.Errorf("Unable to load WebView2Loader.dll from memory: %w", memErr)
 			return
 		}
 		memCreate = memModule.Proc("CreateCoreWebView2EnvironmentWithOptions")