dwm

commit f23dd1aab263eccf82ba1930ecf807653c5a0037
parent 50aea1bc927c4739de23963f7c1b5a94bec06002
Author: bakkeby <bakkeby@gmail.com>
Date:   Thu, 23 Apr 2020 09:50:54 +0200

dwm crashes when opening 50+ clients (tile layout)

Many users new to dwm find themselves caught out by being kicked out to the login manager (dwm crashing) when they open 50+ clients for demonstration purposes. The number of clients reported varies depending on the resolution of the monitor.

The cause of this is due to how the default tile layout calculates the height of the next client based on the position of the previous client. Because clients have a minimum size the (ty) position can exceed that of the window height, resulting in (m->wh - ty) becoming negative. The negative height stored as an unsigned int results in a very large height ultimately resulting in dwm crashing.

This patch adds safeguards to prevent the ty and my positions from exceeding that of the window height.

Diffstat:
M
dwm.c
 | 
6
++++--

1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/dwm.c b/dwm.c
@@ -1689,11 +1689,13 @@ tile(Monitor *m)
 		if (i < m->nmaster) {
 			h = (m->wh - my) / (MIN(n, m->nmaster) - i);
 			resize(c, m->wx, m->wy + my, mw - (2*c->bw), h - (2*c->bw), 0);
-			my += HEIGHT(c);
+			if (my + HEIGHT(c) < m->wh)
+				my += HEIGHT(c);
 		} else {
 			h = (m->wh - ty) / (n - i);
 			resize(c, m->wx + mw, m->wy + ty, m->ww - mw - (2*c->bw), h - (2*c->bw), 0);
-			ty += HEIGHT(c);
+			if (ty + HEIGHT(c) < m->wh)
+				ty += HEIGHT(c);
 		}
 }