From c00faae26370682c307cfb107b12123d10d49053 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Leonardo=20Hern=C3=A1ndez=20Hern=C3=A1ndez?=
 <leohdz172@protonmail.com>
Date: Wed, 7 Sep 2022 23:04:18 -0500
Subject: [PATCH] fix various segfaults when selmon is NULL

---
 dwl.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/dwl.c b/dwl.c
index 3538cf3..0bb551e 100644
--- a/dwl.c
+++ b/dwl.c
@@ -880,7 +880,10 @@ createlayersurface(struct wl_listener *listener, void *data)
 	struct wlr_layer_surface_v1_state old_state;
 
 	if (!wlr_layer_surface->output)
-		wlr_layer_surface->output = selmon->wlr_output;
+		wlr_layer_surface->output = selmon ? selmon->wlr_output : NULL;
+
+	if (!wlr_layer_surface->output)
+		wlr_layer_surface_v1_destroy(wlr_layer_surface);
 
 	layersurface = ecalloc(1, sizeof(LayerSurface));
 	layersurface->type = LayerShell;
@@ -1269,6 +1272,8 @@ fullscreennotify(struct wl_listener *listener, void *data)
 void
 incnmaster(const Arg *arg)
 {
+	if (!arg || !selmon)
+		return;
 	selmon->nmaster = MAX(selmon->nmaster + arg->i, 0);
 	arrange(selmon);
 }
@@ -1948,6 +1953,8 @@ setfullscreen(Client *c, int fullscreen)
 void
 setlayout(const Arg *arg)
 {
+	if (!selmon)
+		return;
 	if (!arg || !arg->v || arg->v != selmon->lt[selmon->sellt])
 		selmon->sellt ^= 1;
 	if (arg && arg->v)
@@ -1963,7 +1970,7 @@ setmfact(const Arg *arg)
 {
 	float f;
 
-	if (!arg || !selmon->lt[selmon->sellt]->arrange)
+	if (!arg || !selmon || !selmon->lt[selmon->sellt]->arrange)
 		return;
 	f = arg->f < 1.0 ? arg->f + selmon->mfact : arg->f - 1.0;
 	if (f < 0.1 || f > 0.9)
@@ -2250,9 +2257,8 @@ void
 tagmon(const Arg *arg)
 {
 	Client *sel = selclient();
-	if (!sel)
-		return;
-	setmon(sel, dirtomon(arg->i), 0);
+	if (sel)
+		setmon(sel, dirtomon(arg->i), 0);
 }
 
 void
@@ -2324,7 +2330,7 @@ toggletag(const Arg *arg)
 void
 toggleview(const Arg *arg)
 {
-	unsigned int newtagset = selmon->tagset[selmon->seltags] ^ (arg->ui & TAGMASK);
+	unsigned int newtagset = selmon ? selmon->tagset[selmon->seltags] ^ (arg->ui & TAGMASK) : 0;
 
 	if (newtagset) {
 		selmon->tagset[selmon->seltags] = newtagset;
@@ -2445,7 +2451,7 @@ urgent(struct wl_listener *listener, void *data)
 void
 view(const Arg *arg)
 {
-	if ((arg->ui & TAGMASK) == selmon->tagset[selmon->seltags])
+	if (selmon && (arg->ui & TAGMASK) == selmon->tagset[selmon->seltags])
 		return;
 	selmon->seltags ^= 1; /* toggle sel tagset */
 	if (arg->ui & TAGMASK)
@@ -2507,7 +2513,7 @@ zoom(const Arg *arg)
 {
 	Client *c, *sel = selclient();
 
-	if (!sel || !selmon->lt[selmon->sellt]->arrange || sel->isfloating)
+	if (!sel || !selmon || !selmon->lt[selmon->sellt]->arrange || sel->isfloating)
 		return;
 
 	/* Search for the first tiled window that is not sel, marking sel as