liberty: comment on pthread_cancel

They can be missing in bare configurations, such as Sway + XWayland.

liberty-xdg.c

@@ -86,24 +86,30 @@ xdg_xsettings_update (struct xdg_xsettings *self, Display *dpy)
 	// TODO: We're supposed to lock the server.
 	// TODO: We're supposed to trap X errors.
 	char *selection = xstrdup_printf ("_XSETTINGS_S%d", DefaultScreen (dpy));
-	Window owner
-		= XGetSelectionOwner (dpy, XInternAtom (dpy, selection, True));
+	Atom selection_atom = XInternAtom (dpy, selection, True);
 	free (selection);
+	if (!selection_atom)
+		return;
+
+	Window owner = XGetSelectionOwner (dpy, selection_atom);
 	if (!owner)
 		return;
 
+	Atom xsettings_atom = XInternAtom (dpy, "_XSETTINGS_SETTINGS", True);
+	if (!xsettings_atom)
+		return;
+
 	Atom actual_type = None;
 	int actual_format = 0;
 	unsigned long nitems = 0, bytes_after = 0;
 	unsigned char *buffer = NULL;
-	Atom xsettings = XInternAtom (dpy, "_XSETTINGS_SETTINGS", True);
 	int status = XGetWindowProperty (dpy,
 		owner,
-		xsettings,
+		xsettings_atom,
 		0L,
 		LONG_MAX,
 		False,
-		xsettings,
+		xsettings_atom,
 		&actual_type,
 		&actual_format,
 		&nitems,
@@ -112,7 +118,7 @@ xdg_xsettings_update (struct xdg_xsettings *self, Display *dpy)
 	if (status != Success || !buffer)
 		return;
 
-	if (actual_type != xsettings
+	if (actual_type != xsettings_atom
 	 || actual_format != 8
 	 || nitems < 12)
 		goto fail;

liberty-xui.c

@@ -1884,6 +1884,8 @@ x11_init (struct poller *poller, struct attrs *app_attrs, size_t app_attrs_len)
 	if (!(g_xui.dpy = XkbOpenDisplay
 		(NULL, &g_xui.xkb_base_event_code, NULL, NULL, NULL, NULL)))
 		exit_fatal ("cannot open display");
+	if (!XftInit (NULL))
+		print_warning ("Fontconfig initialization failed");
 	if (!XftDefaultHasRender (g_xui.dpy))
 		exit_fatal ("XRender is not supported");
 	if (!(g_xui.x11_im = XOpenIM (g_xui.dpy, NULL, NULL, NULL)))
@@ -1912,8 +1914,6 @@ x11_init (struct poller *poller, struct attrs *app_attrs, size_t app_attrs_len)
 	g_xui.x11_xsettings = xdg_xsettings_make ();
 	xdg_xsettings_update (&g_xui.x11_xsettings, g_xui.dpy);
 
-	if (!FcInit ())
-		print_warning ("Fontconfig initialization failed");
 	if (!(g_xui.xft_fonts = x11_font_open (0)))
 		exit_fatal ("cannot open a font");
 

liberty.c

@@ -1209,7 +1209,10 @@ async_make (struct async_manager *manager)
 }
 
 /// Only allowed from the main thread once the job has been started but before
-/// the results have been dispatched
+/// the results have been dispatched.
+///
+/// Note that it may in practice lead to memory leakage, although that's
+/// an implementation issue: https://eissing.org/icing/posts/rip_pthread_cancel/
 static void
 async_cancel (struct async *self)
 {