From 3118ee1e5cd8569cf43a97c1b80a661cfe3f0b6c Mon Sep 17 00:00:00 2001
From: attila <attila@juce.com>
Date: Tue, 22 Oct 2024 16:16:02 +0200
Subject: [PATCH] Linux: Prevent stale ConfigureNotify events from overwriting
 the current window position

---
 modules/juce_gui_basics/native/juce_Windowing_linux.cpp  | 9 ++++++++-
 .../juce_gui_basics/native/juce_XWindowSystem_linux.cpp  | 2 ++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/modules/juce_gui_basics/native/juce_Windowing_linux.cpp b/modules/juce_gui_basics/native/juce_Windowing_linux.cpp
index ae7926bb02..d6d3f322da 100644
--- a/modules/juce_gui_basics/native/juce_Windowing_linux.cpp
+++ b/modules/juce_gui_basics/native/juce_Windowing_linux.cpp
@@ -110,7 +110,13 @@ public:
 
         WeakReference<Component> deletionChecker (&component);
 
-        XWindowSystem::getInstance()->setBounds (windowH, physicalBounds, isNowFullScreen);
+        // If we are in a ConfigureNotify handler then forceSetBounds is being called as a
+        // consequence of X11 telling us what the window size is. There's no need to report this
+        // size back again to X11. By this we are avoiding a pitfall, when we get many subsequent
+        // ConfigureNotify events, many of which has stale size information. By not calling
+        // XWindowSystem::setBounds we are not actualising these old, incorrect sizes.
+        if (! inConfigureNotifyHandler)
+            XWindowSystem::getInstance()->setBounds (windowH, physicalBounds, isNowFullScreen);
 
         fullScreen = isNowFullScreen;
 
@@ -421,6 +427,7 @@ public:
     //==============================================================================
     static bool isActiveApplication;
     bool focused = false;
+    bool inConfigureNotifyHandler = false;
 
 private:
     //==============================================================================
diff --git a/modules/juce_gui_basics/native/juce_XWindowSystem_linux.cpp b/modules/juce_gui_basics/native/juce_XWindowSystem_linux.cpp
index 57d8ae6f88..8e89116f87 100644
--- a/modules/juce_gui_basics/native/juce_XWindowSystem_linux.cpp
+++ b/modules/juce_gui_basics/native/juce_XWindowSystem_linux.cpp
@@ -3773,6 +3773,8 @@ void XWindowSystem::dismissBlockingModals (LinuxComponentPeer* peer) const
 
 void XWindowSystem::handleConfigureNotifyEvent (LinuxComponentPeer* peer, XConfigureEvent& confEvent) const
 {
+    const ScopedValueSetter<bool> scope { peer->inConfigureNotifyHandler, true };
+
     peer->updateWindowBounds();
     peer->updateBorderSize();
     peer->handleMovedOrResized();