[macOS] Fix borderless window maximization.

platform/macos/display_server_macos.h

@@ -111,7 +111,8 @@ public:
 		Size2i size;
 		Vector2i wb_offset = Vector2i(14, 14);
 
-		NSRect last_frame_rect;
+		NSRect last_frame_rect = NSMakeRect(0, 0, 0, 0);
+		NSRect pre_zoom_rect = NSMakeRect(0, 0, 0, 0);
 
 		bool im_active = false;
 		Size2i im_position;

platform/macos/display_server_macos.mm

@@ -2537,7 +2537,13 @@ void DisplayServerMacOS::window_set_mode(WindowMode p_mode, WindowID p_window) {
 		} break;
 		case WINDOW_MODE_MAXIMIZED: {
 			if (NSEqualRects([wd.window_object frame], [[wd.window_object screen] visibleFrame])) {
-				[wd.window_object zoom:nil];
+				if (wd.borderless) {
+					if (wd.pre_zoom_rect.size.width > 0 && wd.pre_zoom_rect.size.height > 0) {
+						[wd.window_object setFrame:wd.pre_zoom_rect display:NO animate:YES];
+					}
+				} else {
+					[wd.window_object zoom:nil];
+				}
 			}
 		} break;
 	}
@@ -2570,7 +2576,12 @@ void DisplayServerMacOS::window_set_mode(WindowMode p_mode, WindowID p_window) {
 		} break;
 		case WINDOW_MODE_MAXIMIZED: {
 			if (!NSEqualRects([wd.window_object frame], [[wd.window_object screen] visibleFrame])) {
-				[wd.window_object zoom:nil];
+				wd.pre_zoom_rect = [wd.window_object frame];
+				if (wd.borderless) {
+					[wd.window_object setFrame:[[wd.window_object screen] visibleFrame] display:NO animate:YES];
+				} else {
+					[wd.window_object zoom:nil];
+				}
 			}
 		} break;
 	}
@@ -2770,6 +2781,7 @@ void DisplayServerMacOS::window_set_flag(WindowFlags p_flag, bool p_enabled, Win
 				[wd.window_object orderOut:nil];
 			}
 			wd.borderless = p_enabled;
+			bool was_maximized = (NSEqualRects([wd.window_object frame], [[wd.window_object screen] visibleFrame]));
 			if (p_enabled) {
 				[wd.window_object setStyleMask:NSWindowStyleMaskBorderless];
 				[wd.window_object setHasShadow:NO];
@@ -2800,6 +2812,9 @@ void DisplayServerMacOS::window_set_flag(WindowFlags p_flag, bool p_enabled, Win
 					[wd.window_object makeKeyAndOrderFront:nil];
 				}
 			}
+			if (was_maximized) {
+				[wd.window_object setFrame:[[wd.window_object screen] visibleFrame] display:NO];
+			}
 		} break;
 		case WINDOW_FLAG_ALWAYS_ON_TOP: {
 			wd.on_top = p_enabled;

platform/macos/godot_window_delegate.mm

@@ -208,6 +208,16 @@
 	[self windowDidResize:notification];
 }
 
+- (BOOL)windowShouldZoom:(NSWindow *)window toFrame:(NSRect)newFrame {
+	if (ds->has_window(window_id)) {
+		DisplayServerMacOS::WindowData &wd = ds->get_window(window_id);
+		if (!wd.borderless && !(NSEqualRects([wd.window_object frame], [[wd.window_object screen] visibleFrame]))) {
+			wd.pre_zoom_rect = [wd.window_object frame];
+		}
+	}
+	return YES;
+}
+
 - (void)windowDidChangeBackingProperties:(NSNotification *)notification {
 	if (!ds->has_window(window_id)) {
 		return;