libxcb-hack-focal.diff

--- a/src/xcb_out.c
+++ b/src/xcb_out.c
@@ -218,6 +218,52 @@
     close_fds(fds, num_fds);
 }
 
+static inline xcb_window_t find_top_window(xcb_connection_t *conn, xcb_window_t wnd)
+{
+    xcb_query_tree_reply_t* treeReply = NULL;
+
+    if (!wnd)
+        return 0;
+
+    do {
+        treeReply = xcb_query_tree_reply(conn, xcb_query_tree(conn, wnd), NULL);
+
+        if (!treeReply || treeReply->root == wnd) {
+            wnd = 0;
+            break;
+        }
+        if (treeReply->root == treeReply->parent) {
+            break;
+        }
+
+        wnd = treeReply->parent;
+        free(treeReply);
+    } while(1);
+
+    free(treeReply);
+    return wnd;
+}
+
+static inline int check_grab(xcb_connection_t *conn, struct iovec *vector)
+{
+    xcb_get_input_focus_reply_t* focusReply = xcb_get_input_focus_reply(conn, xcb_get_input_focus(conn), NULL);
+
+    // TRICK: grab_window at offset 0x04 for all grab ops
+    xcb_window_t req_wnd = *(xcb_window_t *)((uint8_t *)vector[0].iov_base + 4);
+    xcb_window_t focus_wnd = focusReply->focus;
+
+    free(focusReply);
+
+    // fprintf(stderr, "%s-raw\treq %X, focus %X\n", __func__, req_wnd, focus_wnd);
+
+    req_wnd = find_top_window(conn, req_wnd);
+    focus_wnd = find_top_window(conn, focus_wnd);
+
+    // fprintf(stderr, "%s-top\treq %X, focus %X\n", __func__, req_wnd, focus_wnd);
+
+    return (focus_wnd && focus_wnd == req_wnd);
+}
+
 uint64_t xcb_send_request_with_fds64(xcb_connection_t *c, int flags, struct iovec *vector,
                 const xcb_protocol_request_t *req, unsigned int num_fds, int *fds)
 {
@@ -234,6 +280,21 @@
     assert(c != 0);
     assert(vector != 0);
     assert(req->count > 0);
+
+    if (req->ext == NULL) {
+        switch (req->opcode) {
+        case XCB_GRAB_POINTER:
+        case XCB_GRAB_BUTTON:
+        case XCB_GRAB_KEYBOARD:
+        case XCB_GRAB_KEY:
+            if (check_grab(c, vector))
+                break;
+            // else fall through;
+        case XCB_SET_INPUT_FOCUS:
+            close_fds(fds, num_fds);
+            return 0;
+        }
+    }
 
     if(!(flags & XCB_REQUEST_RAW))
     {