output: set custom output mode on wlopm --on

This works around a wlroots issue:
https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3946

Fixes: #2576

diff --git a/src/output.c b/src/output.c
index 388d7623ce0df3aa9640d47861ce473311208762..8a5b5825619be4de63ab3ad2091f3c70c9fb8740 100644 (file)
--- a/src/output.c
+++ b/src/output.c
@@ -1073,6 +1073,28 @@ handle_output_power_manager_set_mode(struct wl_listener *listener, void *data)
                break;
        case ZWLR_OUTPUT_POWER_V1_MODE_ON:
                wlr_output_state_set_enabled(&output->pending, true);
+               if (!event->output->current_mode) {
+                       /*
+                        * This output uses a custom mode, due to a wlroots DRM
+                        * issue we have to ensure the output commit includes a
+                        * modeset. This is made more difficult by wlroots
+                        * removing a requested change for a custom resolution
+                        * from the output state when it matches the wlr_output
+                        * one. To in turn work around this issue we temporarily
+                        * change the custom wlr_output resolution.
+                        *
+                        * See: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3946
+                        *
+                        * TODO: To be removed once the underlying wlroots issue
+                        *       has been fixed and released. Likely only after
+                        *       labwc starts tracking wlroots 0.19 to keep older
+                        *       0.18.x releases working as expected.
+                        */
+                       int width = event->output->width;
+                       event->output->width++;
+                       wlr_output_state_set_custom_mode(&output->pending, width,
+                               event->output->height, event->output->refresh);
+               }
                output_state_commit(output);
                /*
                 * Re-set the cursor image so that the cursor