From: Andrew J. Hesford <ajh@sideband.org>
Date: Wed, 11 Dec 2024 19:57:07 +0000 (-0500)
Subject: config: only default to xwayland persistence on old wlroots versions
X-Git-Url: https://git.mdlowis.com/?a=commitdiff_plain;h=df6081b52c6e77161c5ed58c3adf57d0843f1c57;p=proto%2Flabwc.git

config: only default to xwayland persistence on old wlroots versions

This is a compile-time check, so it will be too conservative if somebody
updates wlroots after building labwc, but that is still better than the
alternatives.
---

diff --git a/docs/labwc-config.5.scd b/docs/labwc-config.5.scd
index d9f939fa..1f48f62a 100644
--- a/docs/labwc-config.5.scd
+++ b/docs/labwc-config.5.scd
@@ -219,13 +219,12 @@ this is for compatibility with Openbox.
 *<core><xwaylandPersistence>* [yes|no]
 	Keep XWayland alive even when no clients are connected, rather than
 	using a "lazy" policy that allows the server to launch on demand and die
-	when it is no longer needed. Default is yes.
+	when it is no longer needed.
 
-	This is only temporarily defaulting to yes to avoid a bug that is
-	present in wlroots <0.18.2 resulting in a compositor crash when
-	performing a drag-and-drop action at the same time as the XWayland
-	server is shutting down. This will be reverted to a default "no" when
-	wlroots-0.18.2 can be linked with.
+	When labwc is compiled with wlroots 0.18.2 or later, the default is no.
+	When labwc is compiled with wlroots < 0.18.2, the default is yes to
+	avoid a wlroots bug that can result in compositor crashes when
+	performing drag-and-drop actions when the XWayland server is shut down.
 
 	Note: changing this setting requires a restart of labwc.
 
diff --git a/src/config/rcxml.c b/src/config/rcxml.c
index a8cb9d3b..bdd84291 100644
--- a/src/config/rcxml.c
+++ b/src/config/rcxml.c
@@ -14,6 +14,7 @@
 #include <wayland-server-core.h>
 #include <wlr/util/box.h>
 #include <wlr/util/log.h>
+#include <wlr/version.h>
 #include "action.h"
 #include "common/dir.h"
 #include "common/list.h"
@@ -36,6 +37,9 @@
 #include "window-rules.h"
 #include "workspaces.h"
 
+#define LAB_WLR_VERSION_OLDER_THAN(major, minor, micro) \
+	(WLR_VERSION_NUM < (((major) << 16) | ((minor) << 8) | (micro)))
+
 static bool in_regions;
 static bool in_usable_area_override;
 static bool in_keybind;
@@ -1089,16 +1093,14 @@ entry(xmlNode *node, char *nodename, char *content)
 	} else if (!strcasecmp(nodename, "xwaylandPersistence.core")) {
 		set_bool(content, &rc.xwayland_persistence);
 
-		/*
-		 * TODO: Temporary warning message. Revert when wlroots-0.18.2
-		 * can be linked with.
-		 */
+#if LAB_WLR_VERSION_OLDER_THAN(0, 18, 2)
 		if (!rc.xwayland_persistence) {
-			wlr_log(WLR_ERROR, "setting xwaylandPersistence to 'no' "
-				"is not encouraged unless wlroots-0.18.2 is used "
-				"since it has a potential risk of crashing the "
-				"entire session. See #2371 for details.");
+			wlr_log(WLR_ERROR, "to avoid the risk of a fatal crash, "
+				"setting xwaylandPersistence to 'no' is only "
+				"recommended when labwc is compiled against "
+				"wlroots >= 0.18.2. See #2371 for details.");
 		}
+#endif
 	} else if (!strcasecmp(nodename, "x.cascadeOffset.placement")) {
 		rc.placement_cascade_offset_x = atoi(content);
 	} else if (!strcasecmp(nodename, "y.cascadeOffset.placement")) {
@@ -1463,7 +1465,16 @@ rcxml_init(void)
 	rc.adaptive_sync = LAB_ADAPTIVE_SYNC_DISABLED;
 	rc.allow_tearing = false;
 	rc.reuse_output_mode = false;
+
+#if LAB_WLR_VERSION_OLDER_THAN(0, 18, 2)
+	/*
+	 * For wlroots < 0.18.2, keep xwayland alive by default to work around
+	 * a fatal crash when the X server is terminated during drag-and-drop.
+	 */
 	rc.xwayland_persistence = true;
+#else
+	rc.xwayland_persistence = false;
+#endif
 
 	init_font_defaults(&rc.font_activewindow);
 	init_font_defaults(&rc.font_inactivewindow);