Changeset 0b6fad9 in mainline for uspace/srv/hid/display/seat.c

Timestamp:

2023-08-10T14:25:09Z (14 months ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

master, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

46bd63c9

Parents:

24be331e

git-author:

Jiri Svoboda <jiri@…> (2023-08-09 17:24:57)

git-committer:

Jiri Svoboda <jiri@…> (2023-08-10 14:25:09)

Message:

Avoid null pointer dereference when switching focus

I hit this when I created a new seat and there was no focused window.
It could probably also happen e.g. if there are no windows.
Now we also set focus for a newly created seat.

File:

• uspace/srv/hid/display/seat.c (modified) (2 diffs)

uspace/srv/hid/display/seat.c

@@ -88 +88 @@
         seat->client_cursor = display->cursor[dcurs_arrow];
         seat->wm_cursor = NULL;
+        seat->focus = ds_display_first_window(display);
 
         *rseat = seat;
@@ -223 +224 @@
         ds_window_t *nwnd;
 
-        /* Find alternate window that is not a system window */
-        nwnd = ds_window_find_next(seat->focus, ~wndf_system);
+        if (seat->focus != NULL) {
+                /* Find alternate window that is not a system window */
+                nwnd = ds_window_find_next(seat->focus, ~wndf_system);
+        } else {
+                /* Currently no focus. Focus topmost window. */
+                nwnd = ds_display_first_window(seat->display);
+        }
 
         /* Only switch focus if there is another window */