From 90e72dbd986d927af1cbc62891cde1255c29ad72 Mon Sep 17 00:00:00 2001
From: attila <attila@juce.com>
Date: Fri, 17 Jan 2025 16:12:51 +0100
Subject: [PATCH] Windows: Fix faulty mechanism for creating multiple WebView2
 instances serially

Prior to this commit it was possible for the WebBrowserComponent
implementation on Windows to end up in an infinite loop if multiple
WebBrowserComponent objects were being created at the same time.

When an instance was already being created, the createWebView() call for
the second would place it in a queue and return without initiating its
creation. When the first WebView finishes creation, it calls the
handleAsyncUpdate() function of the second. However handleAsyncUdpate()
would see that the webViewBeingCreated helper variable was already true
and not call createWebView(), hence the second WebView would never be
created.

If, in the meantime, the scriptsWaitingForExecution variable wasn't
empty, handleAsyncUpdate() would endlessly call triggerAsyncUpdate().
---
 .../native/juce_WebBrowserComponent_windows.cpp       | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/modules/juce_gui_extra/native/juce_WebBrowserComponent_windows.cpp b/modules/juce_gui_extra/native/juce_WebBrowserComponent_windows.cpp
index 0ff48a8a21..ddd734329b 100644
--- a/modules/juce_gui_extra/native/juce_WebBrowserComponent_windows.cpp
+++ b/modules/juce_gui_extra/native/juce_WebBrowserComponent_windows.cpp
@@ -686,7 +686,6 @@ public:
         if (webView == nullptr)
         {
             scriptsWaitingForExecution.push_back ({ script, std::move (callbackIn) });
-            triggerAsyncUpdate();
             return;
         }
 
@@ -1059,6 +1058,7 @@ private:
                     {
                         if (weakThis != nullptr)
                         {
+                            weakThis->triggerAsyncUpdate();
                             webView2ConstructionHelper.webView2BeingCreated = nullptr;
 
                             if (controller != nullptr)
@@ -1156,15 +1156,9 @@ private:
     //==============================================================================
     void handleAsyncUpdate() override
     {
-        if (webView == nullptr && ! webViewBeingCreated)
+        if (webView == nullptr)
         {
-            webViewBeingCreated = true;
             createWebView();
-        }
-
-        if (webView == nullptr && ! scriptsWaitingForExecution.empty())
-        {
-            triggerAsyncUpdate();
             return;
         }
 
@@ -1206,7 +1200,6 @@ private:
     WebViewHandle webViewHandle;
     ComSmartPtr<ICoreWebView2Controller> webViewController;
     ComSmartPtr<ICoreWebView2> webView;
-    bool webViewBeingCreated = false;
 
     EventRegistrationToken navigationStartingToken   { 0 },
                            newWindowRequestedToken   { 0 },