From 86617c055046e9d9689f6b056a0b020776d43037 Mon Sep 17 00:00:00 2001
From: jqdg <jqdg@users.noreply.github.com>
Date: Sun, 8 Aug 2021 23:00:51 -0700
Subject: [PATCH] Fix zombie windows in Mac OS when switching to/from
 fullscreen

---
 src/SFML/Window/OSX/SFWindow.h         | 12 ++++++++++++
 src/SFML/Window/OSX/SFWindow.m         |  7 +++++++
 src/SFML/Window/OSX/WindowImplCocoa.mm |  6 +++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/SFML/Window/OSX/SFWindow.h b/src/SFML/Window/OSX/SFWindow.h
index a59101a9d..7e3d02929 100644
--- a/src/SFML/Window/OSX/SFWindow.h
+++ b/src/SFML/Window/OSX/SFWindow.h
@@ -57,6 +57,18 @@
 ////////////////////////////////////////////////////////////
 -(BOOL)canBecomeKeyWindow;
 
+////////////////////////////////////////////////////////////
+/// \brief Allow fullscreen windows to become the main window
+///
+/// By default, fullscreen windows (using NSBorderlessWindowMask)
+/// cannot become the main window, so this method is changed to
+/// always return YES.
+///
+/// \return YES
+///
+////////////////////////////////////////////////////////////
+-(BOOL)canBecomeMainWindow;
+
 ////////////////////////////////////////////////////////////
 /// \brief Prevent system alert
 ///
diff --git a/src/SFML/Window/OSX/SFWindow.m b/src/SFML/Window/OSX/SFWindow.m
index ff60c6c57..507f258bc 100644
--- a/src/SFML/Window/OSX/SFWindow.m
+++ b/src/SFML/Window/OSX/SFWindow.m
@@ -45,6 +45,13 @@
 }
 
 
+////////////////////////////////////////////////////////
+-(BOOL)canBecomeMainWindow
+{
+    return YES;
+}
+
+
 ////////////////////////////////////////////////////////
 -(void)keyDown:(NSEvent*)theEvent
 {
diff --git a/src/SFML/Window/OSX/WindowImplCocoa.mm b/src/SFML/Window/OSX/WindowImplCocoa.mm
index 091b7b2d6..b4453a98a 100644
--- a/src/SFML/Window/OSX/WindowImplCocoa.mm
+++ b/src/SFML/Window/OSX/WindowImplCocoa.mm
@@ -154,7 +154,11 @@ WindowImplCocoa::~WindowImplCocoa()
     // Put the next window in front, if any.
     NSArray* windows = [NSApp orderedWindows];
     if ([windows count] > 0)
-        [[windows objectAtIndex:0] makeKeyAndOrderFront:nil];
+    {
+        NSWindow *nextWindow = [windows objectAtIndex:0];
+        if ([nextWindow isVisible])
+            [nextWindow makeKeyAndOrderFront:nil];
+    }
 
     drainThreadPool(); // Make sure everything was freed
     // This solve some issue when sf::Window::Create is called for the