output_id_pool is defined as a uint32_t, thus ffs() provides a range of 1-32 available id numbers. When the 33rd output is enabled, Weston will set the ID to (unsigned)(-1) and thus lead to some unexpected behaviors.
I'm not sure what the best way to handle this error would be since this is in an initialization routine, but at least let's document the potential error condition with an assert(). Signed-off-by: Bryce Harrington <[email protected]> --- src/compositor.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/compositor.c b/src/compositor.c index 230fd78..a2a03a7 100644 --- a/src/compositor.c +++ b/src/compositor.c @@ -4303,6 +4303,9 @@ weston_output_init(struct weston_output *output, struct weston_compositor *c, { struct wl_event_loop *loop; + /* Verify we haven't reached the limit of 32 available output IDs */ + assert(ffs(~c->output_id_pool) > 0); + output->compositor = c; output->x = x; output->y = y; -- 1.9.1 _______________________________________________ wayland-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/wayland-devel
