https://bugs.gentoo.org/768285
https://midnight-commander.org/ticket/4192

From 6394547dbffbad44ea50c64c282de4b610ca07bf Mon Sep 17 00:00:00 2001
From: Sergei Trofimovich <slyfox@gentoo.org>
Date: Wed, 3 Feb 2021 09:47:13 +0300
Subject: [PATCH] Ticket #4192: fix crash if shadow is out of screen.

(tty_clip): add extra tests for area boundaries.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
---
 lib/tty/tty-ncurses.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/tty/tty-ncurses.c b/lib/tty/tty-ncurses.c
index 03235cd5b..5cddf5059 100644
--- a/lib/tty/tty-ncurses.c
+++ b/lib/tty/tty-ncurses.c
@@ -152,9 +152,16 @@ tty_clip (int *y, int *x, int *rows, int *cols)
 
     if (*y + *rows > LINES)
         *rows = LINES - *y;
+
+    if (*rows <= 0)
+        return FALSE;
+
     if (*x + *cols > COLS)
         *cols = COLS - *x;
 
+    if (*cols <= 0)
+        return FALSE;
+
     return TRUE;
 }
 
-- 
2.30.0