Fix segfault in wlr_output_manager_v1_set_configuration

Calling wlr_output_manager_v1_set_configuration with an enabled output
and a NULL mode is incorrect if the output doesn't support modes.

When DPMS'ing an output, wlr_output_enable(output, false) is called.
This de-allocates the CRTC and sets wlr_output.current_mode to NULL.

Because we mark DPMS'ed outputs as enabled, we also need to provide a
correct output mode. Add a field to sway_output to hold the current
mode.

Closes: https://github.com/swaywm/wlroots/issues/1867

1 files changed, 1 insertions, 0 deletions

diff --git a/sway/tree/output.c b/sway/tree/output.c
index 33fdee5e..07f04ee5 100644
--- a/sway/tree/output.c
+++ b/sway/tree/output.c
@@ -269,6 +269,7 @@ void output_disable(struct sway_output *output) {
 
         output->enabled = false;
         output->configured = false;
+        output->current_mode = NULL;
 
         arrange_root();
 }