From: Toni Wilen <twilen@winuae.net>
Date: Sun, 8 Apr 2018 10:41:32 +0000 (+0300)
Subject: Fix divide by zero if pitch is zero. (single line blit)
X-Git-Tag: 4000~133
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=71db96ccc79b4e7ae62fcbdfbc8a35b06c32784d;p=francis%2Fwinuae.git

Fix divide by zero if pitch is zero. (single line blit)
---

diff --git a/qemuvga/cirrus_vga.cpp b/qemuvga/cirrus_vga.cpp
index 9502dca9..9e6f53fc 100644
--- a/qemuvga/cirrus_vga.cpp
+++ b/qemuvga/cirrus_vga.cpp
@@ -188,9 +188,15 @@ static void check_blit(int32_t addr, uint32_t mask, int pitch, int width, int *h
 		off -= width * (depth / 8);
 	}
 	if (off > mask + 1) {
-		h -= (off - (mask + 1) + pitch - 1) / pitch;
+		if (pitch)
+			h -= (off - (mask + 1) + pitch - 1) / pitch;
+		else
+			h = 0;
 	} else if (off < 0) {
-		h -= ((-off) + pitch - 1) / pitch;
+		if (pitch)
+			h -= ((-off) + pitch - 1) / pitch;
+		else
+			h = 0;
 	}
 	if (h < 0)
 		h = 0;