SDLBackend: do not leak Super+KEY shortcuts to DE

src/Backends/SDLBackend.cpp

@@ -742,14 +742,20 @@ namespace gamescope
 						{
 							break;
 						}
+
+						// Temporary grab keyboard while Super is pressed
+						if (!g_bGrabbed && !g_bShortcutGrabbed && key == KEY_LEFTMETA) {
+							g_bShortcutGrabbed = true;
+							SDL_SetWindowKeyboardGrab(m_Connector.GetSDLWindow(), g_bShortcutGrabbed);
+						}
 					}
 				}
 				[[fallthrough]];
 				case SDL_KEYUP:
 				{
 					uint32_t key = SDLScancodeToLinuxKey( event.key.keysym.scancode );
 
-					if ( event.type == SDL_KEYUP && ( event.key.keysym.mod & KMOD_LGUI ) )
+					if ( event.type == SDL_KEYUP && ( (event.key.keysym.mod & KMOD_LGUI) != 0 || g_bShortcutGrabbed ) )
 					{
 						bool handled = true;
 						switch ( key )
@@ -781,14 +787,25 @@ namespace gamescope
 							case KEY_S:
 								gamescope::CScreenshotManager::Get().TakeScreenshot( true );
 								break;
-							case KEY_G:
+							case KEY_G: {
+								// Reset shortcut grab and allow normal grab w/ title change
+								if (g_bShortcutGrabbed) {
+									g_bShortcutGrabbed = false;
+								}
 								g_bGrabbed = !g_bGrabbed;
 								SDL_SetWindowKeyboardGrab( m_Connector.GetSDLWindow(), g_bGrabbed ? SDL_TRUE : SDL_FALSE );
 
 								SDL_Event event;
 								event.type = GetUserEventIndex( GAMESCOPE_SDL_EVENT_TITLE );
 								SDL_PushEvent( &event );
-								break;
+							}	break;
+							case KEY_LEFTMETA: {
+								// Release shortcut grab
+								if (g_bShortcutGrabbed) {
+									g_bShortcutGrabbed = false;
+									SDL_SetWindowKeyboardGrab(m_Connector.GetSDLWindow(), g_bShortcutGrabbed);
+								}
+							}	break;
 							default:
 								handled = false;
 						}

src/main.cpp

@@ -303,6 +303,7 @@ bool g_bFullscreen = false;
 bool g_bForceRelativeMouse = false;
 
 bool g_bGrabbed = false;
+bool g_bShortcutGrabbed = false;
 
 float g_mouseSensitivity = 1.0;
 

src/main.hpp

@@ -25,6 +25,7 @@ extern bool g_bForceInternal;
 extern bool g_bFullscreen;
 
 extern bool g_bGrabbed;
+extern bool g_bShortcutGrabbed;
 
 extern float g_mouseSensitivity;
 extern const char *g_sOutputName;