From 190d3cd72d37dba283fc2ee66b3e3dee38c295d0 Mon Sep 17 00:00:00 2001
From: Sheldon Lee <sheldon.m.lee@gmail.com>
Date: Thu, 23 Dec 2021 05:40:26 +0800
Subject: [PATCH] Fixed segfault issues with moving windows between monitors.
 Still some issues with centerfirst states persistion when moving windows
 between monitors.

---
 dwm.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/dwm.c b/dwm.c
index 6c56a22..a7a8f85 100644
--- a/dwm.c
+++ b/dwm.c
@@ -132,6 +132,7 @@ struct Monitor {
 	Window barwin;
 	const Layout *lt[2];
 	Pertag *pertag;
+	int centerfirst;
 };
 
 typedef struct {
@@ -668,6 +669,7 @@ createmon(void)
 	strncpy(m->ltsymbol, layouts[0].symbol, sizeof m->ltsymbol);
 	m->pertag = ecalloc(1, sizeof(Pertag));
 	m->pertag->curtag = m->pertag->prevtag = 1;
+	m->centerfirst = centerfirst;
 
 	for (i = 0; i <= LENGTH(tags); i++) {
 		m->pertag->nmasters[i] = m->nmaster;
@@ -679,7 +681,7 @@ createmon(void)
 
 		m->pertag->showbars[i] = m->showbar;
 
-		m->pertag->centerfirst[i] = centerfirst;
+		m->pertag->centerfirst[i] = m->centerfirst;
 	}
 
 	return m;
@@ -898,7 +900,7 @@ focusstack(const Arg *arg)
 	if (c) {
 		focus(c);
 		restack(selmon);
-		//XWarpPointer(dpy, None, c->win, 0, 0, 0, 0, c->w/2, c->h/2);
+		XWarpPointer(dpy, None, c->win, 0, 0, 0, 0, c->w/2, c->h/2);
 	}
 }
 
@@ -1762,13 +1764,13 @@ tile(Monitor *m)
 		return;
 
 	c = nexttiled(m->clients);
-	if (n == 1 && m->pertag->centerfirst[m->pertag->curtag] && c && c->iscentered){
+	if (n <= 1 && selmon->centerfirst && c && c->iscentered){
 		resize(
 				c, 
 				m->wx + m->ww*(1 - m->mfact)/2,
 				m->wy,
-				m->ww * m->mfact - 2 * m->sel->bw,
-				m->wh - 2 * m->sel->bw,
+				m->ww * m->mfact - 2 * c->bw,
+				m->wh - 2 * c->bw,
 				0
 				);
 		return;
@@ -1857,6 +1859,7 @@ toggleview(const Arg *arg)
 		selmon->sellt = selmon->pertag->sellts[selmon->pertag->curtag];
 		selmon->lt[selmon->sellt] = selmon->pertag->ltidxs[selmon->pertag->curtag][selmon->sellt];
 		selmon->lt[selmon->sellt^1] = selmon->pertag->ltidxs[selmon->pertag->curtag][selmon->sellt^1];
+		selmon->centerfirst = selmon->pertag->centerfirst[selmon->pertag->curtag];
 
 		if (selmon->showbar != selmon->pertag->showbars[selmon->pertag->curtag])
 			togglebar(NULL);
@@ -2184,6 +2187,7 @@ view(const Arg *arg)
 	selmon->sellt = selmon->pertag->sellts[selmon->pertag->curtag];
 	selmon->lt[selmon->sellt] = selmon->pertag->ltidxs[selmon->pertag->curtag][selmon->sellt];
 	selmon->lt[selmon->sellt^1] = selmon->pertag->ltidxs[selmon->pertag->curtag][selmon->sellt^1];
+	selmon->centerfirst = selmon->pertag->centerfirst[selmon->pertag->curtag];
 
 	if (selmon->showbar != selmon->pertag->showbars[selmon->pertag->curtag])
 		togglebar(NULL);
@@ -2423,7 +2427,7 @@ togglecenterfirst(const Arg* arg)
 {
 	if (!arg || !selmon->lt[selmon->sellt]->arrange)
 		return;
-	selmon->pertag->centerfirst[selmon->pertag->curtag] ^= 1;	
+	selmon->centerfirst = selmon->pertag->centerfirst[selmon->pertag->curtag] ^= 1;	
 	arrange(selmon);
 }