X11: Ignore ConfigureNotify events containing stale information

modules/juce_gui_basics/native/juce_Windowing_linux.cpp

@@ -116,7 +116,7 @@ public:
         // 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);
+            moveResizeSerial = jmax (moveResizeSerial, XWindowSystem::getInstance()->setBounds (windowH, physicalBounds, isNowFullScreen).value_or (0));
 
         fullScreen = isNowFullScreen;
 
@@ -429,6 +429,11 @@ public:
     bool focused = false;
     bool inConfigureNotifyHandler = false;
 
+    unsigned long getMoveResizeSerial() const
+    {
+        return moveResizeSerial;
+    }
+
 private:
     //==============================================================================
     class LinuxRepaintManager
@@ -605,6 +610,7 @@ private:
     double currentScaleFactor = 1.0;
     Array<Component*> glRepaintListeners;
     ScopedWindowAssociation association;
+    unsigned long moveResizeSerial = 0;
 
     //==============================================================================
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (LinuxComponentPeer)

modules/juce_gui_basics/native/juce_XWindowSystem_linux.cpp

@@ -1736,7 +1736,7 @@ void XWindowSystem::setVisible (::Window windowH, bool shouldBeVisible) const
         X11Symbols::getInstance()->xUnmapWindow (display, windowH);
 }
 
-void XWindowSystem::setBounds (::Window windowH, Rectangle<int> newBounds, bool isFullScreen) const
+std::optional<unsigned long> XWindowSystem::setBounds (::Window windowH, Rectangle<int> newBounds, bool isFullScreen) const
 {
     jassert (windowH != 0);
 
@@ -1792,12 +1792,16 @@ void XWindowSystem::setBounds (::Window windowH, Rectangle<int> newBounds, bool
             return {};
         }();
 
+        const auto serial = X11Symbols::getInstance()->xNextRequest (display);
         X11Symbols::getInstance()->xMoveResizeWindow (display, windowH,
                                                       newBounds.getX() - nativeWindowBorder.getLeft(),
                                                       newBounds.getY() - nativeWindowBorder.getTop(),
                                                       (unsigned int) newBounds.getWidth(),
                                                       (unsigned int) newBounds.getHeight());
+        return serial;
     }
+
+    return std::nullopt;
 }
 
 void XWindowSystem::startHostManagedResize (::Window windowH,
@@ -3780,6 +3784,11 @@ void XWindowSystem::dismissBlockingModals (LinuxComponentPeer* peer) const
 
 void XWindowSystem::handleConfigureNotifyEvent (LinuxComponentPeer* peer, XConfigureEvent& confEvent) const
 {
+    // If the incoming event serial is smaller than the serial of a move/resize request we sent previously,
+    // then we should ignore the incoming event because it will conflict with the pending request.
+    if (confEvent.serial < peer->getMoveResizeSerial())
+        return;
+
     const ScopedValueSetter<bool> scope { peer->inConfigureNotifyHandler, true };
 
     peer->updateWindowBounds();

modules/juce_gui_basics/native/juce_XWindowSystem_linux.h

@@ -187,7 +187,7 @@ public:
     void setTitle (::Window, const String&) const;
     void setIcon (::Window , const Image&) const;
     void setVisible (::Window, bool shouldBeVisible) const;
-    void setBounds (::Window, Rectangle<int>, bool fullScreen) const;
+    [[nodiscard]] std::optional<unsigned long> setBounds (::Window, Rectangle<int>, bool fullScreen) const;
     void updateConstraints (::Window) const;
 
     ComponentPeer::OptionalBorderSize getBorderSize (::Window) const;