core: unmap overlay window when we first acquire it

It used to be unmap when we receive its MapNotify, but now since we discard
events received before we grab X server, that event it lost. But it
turns out we can just unmap it when it's first created, no need to wait
for the MapNotify.

Partially fix #160

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/compton.c

@@ -1104,20 +1104,17 @@ static bool init_overlay(session_t *ps) {
 	if (ps->overlay) {
 		// Set window region of the overlay window, code stolen from
 		// compiz-0.8.8
-		xcb_generic_error_t *e;
-		e = XCB_SYNCED_VOID(xcb_shape_mask, ps->c, XCB_SHAPE_SO_SET,
-		                    XCB_SHAPE_SK_BOUNDING, ps->overlay, 0, 0, 0);
-		if (e) {
+		if (!XCB_AWAIT_VOID(xcb_shape_mask, ps->c, XCB_SHAPE_SO_SET,
+		                    XCB_SHAPE_SK_BOUNDING, ps->overlay, 0, 0, 0)) {
 			log_fatal("Failed to set the bounding shape of overlay, giving "
 			          "up.");
-			exit(1);
+			return false;
 		}
-		e = XCB_SYNCED_VOID(xcb_shape_rectangles, ps->c, XCB_SHAPE_SO_SET,
+		if (!XCB_AWAIT_VOID(xcb_shape_rectangles, ps->c, XCB_SHAPE_SO_SET,
 		                    XCB_SHAPE_SK_INPUT, XCB_CLIP_ORDERING_UNSORTED,
-		                    ps->overlay, 0, 0, 0, NULL);
-		if (e) {
+		                    ps->overlay, 0, 0, 0, NULL)) {
 			log_fatal("Failed to set the input shape of overlay, giving up.");
-			exit(1);
+			return false;
 		}
 
 		// Listen to Expose events on the overlay
@@ -1128,17 +1125,15 @@ static bool init_overlay(session_t *ps) {
 		// overlay
 		// root_damage = XDamageCreate(ps->dpy, root, XDamageReportNonEmpty);
 
-		// Unmap overlay, firstly. But this typically does not work because
-		// the window isn't created yet.
-		// xcb_unmap_window(c, ps->overlay);
-		// XFlush(ps->dpy);
+		// Unmap the overlay, we will map it when needed in redir_start
+		XCB_AWAIT_VOID(xcb_unmap_window, ps->c, ps->overlay);
 	} else {
 		log_error("Cannot get X Composite overlay window. Falling "
 		          "back to painting on root window.");
 	}
 	log_debug("overlay = %#010x", ps->overlay);
 
-	return ps->overlay;
+	return true;
 }
 
 /**
@@ -1850,7 +1845,7 @@ static session_t *session_init(int argc, char **argv, Display *dpy,
 			log_fatal("No XRandR extension. sw-opti, refresh-rate or "
 			          "xinerama-shadow-crop "
 			          "cannot be enabled.");
-			exit(1);
+			goto err;
 		}
 	}
 
@@ -1864,7 +1859,9 @@ static session_t *session_init(int argc, char **argv, Display *dpy,
 
 	// Overlay must be initialized before double buffer, and before creation
 	// of OpenGL context.
-	init_overlay(ps);
+	if (!init_overlay(ps)) {
+		goto err;
+	}
 
 	ps->drivers = detect_driver(ps->c, ps->backend_data, ps->root);
 

src/event.c

@@ -169,7 +169,6 @@ static inline void ev_focus_out(session_t *ps, xcb_focus_out_event_t *ev) {
 
 static inline void ev_create_notify(session_t *ps, xcb_create_notify_event_t *ev) {
 	assert(ev->parent == ps->root);
-	// TODO delay fill_win
 	add_win_top(ps, ev->window);
 }
 

src/x.h

@@ -47,9 +47,20 @@ struct xvisual_info {
 	xcb_visualid_t visual;
 };
 
-#define XCB_SYNCED_VOID(func, c, ...)                                                    \
-	xcb_request_check(c, func##_checked(c, __VA_ARGS__));
-#define XCB_SYNCED(func, c, ...)                                                         \
+#define XCB_AWAIT_VOID(func, c, ...)                                                     \
+	({                                                                               \
+		bool success = true;                                                     \
+		__auto_type e = xcb_request_check(c, func##_checked(c, __VA_ARGS__));    \
+		if (e) {                                                                 \
+			x_print_error(e->sequence, e->major_code, e->minor_code,         \
+			              e->error_code);                                    \
+			free(e);                                                         \
+			success = false;                                                 \
+		}                                                                        \
+		success;                                                                 \
+	})
+
+#define XCB_AWAIT(func, c, ...)                                                          \
 	({                                                                               \
 		xcb_generic_error_t *e = NULL;                                           \
 		__auto_type r = func##_reply(c, func(c, __VA_ARGS__), &e);               \