From c0526d856d6a93148412b50d32d4f618563505f2 Mon Sep 17 00:00:00 2001
From: Consolatis <35009135+Consolatis@users.noreply.github.com>
Date: Wed, 12 Feb 2025 17:04:13 +0100
Subject: [PATCH] output: set custom output mode on wlopm --on

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

Fixes: #2576
---
 src/output.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/output.c b/src/output.c
index 388d7623..8a5b5825 100644
--- 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