backend/headless/output.c:132:3: error: format specifies type 'long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat]
++backend->last_output_num);
^~~~~~~~~~~~~~~~~~~~~~~~~~
backend/noop/output.c:72:3: error: format specifies type 'long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat]
++backend->last_output_num);
^~~~~~~~~~~~~~~~~~~~~~~~~~
backend/wayland/output.c:294:3: error: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat]
++backend->last_output_num);
^~~~~~~~~~~~~~~~~~~~~~~~~~
backend/x11/output.c:150:3: error: format specifies type 'long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat]
++x11->last_output_num);
^~~~~~~~~~~~~~~~~~~~~~
This improves the way the output numbers are handled for the headless
backend. Instead of using the number of active outputs plus one, the
last used number is stored and new outputs will increment it. This
fixes the situation where you start with one output, create a second,
close the first, and create a third. Without this, both outputs will be
HEADLESS-2, which causes an issue since the identifier will also be
identical. With this, the last output is HEADLESS-3 and the outputs can
be distinguished.
The backend destroy signal is emitted before the output_remove
signal is. When the destroy signal is emitted listeners remove
their output_remove listener, so the output_remove signal is never
received and listeners have an invalid output pointer.
The correct way to solve this would be to remove the output_remove
signal completely and use the wlr_output.events.destroy signal
instead. This isn't yet possible because wl_signal_emit is unsafe
and listeners cannot be removed in listeners.