From 23b565cec544e51daf902fba1a2bb4ce0c97ced0 Mon Sep 17 00:00:00 2001
From: Eidolon <furyhunter600@gmail.com>
Date: Tue, 30 Jan 2024 17:01:09 -0600
Subject: [PATCH] Drop papersprite draws that are too wide

This prevents an arithmetic overflow when evaluating xscale, resulting
in a negative xscale.
---
 src/r_things.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/r_things.cpp b/src/r_things.cpp
index 8dcd89df6..d83e61f27 100644
--- a/src/r_things.cpp
+++ b/src/r_things.cpp
@@ -2081,11 +2081,21 @@ static void R_ProjectSprite(mobj_t *thing)
 		if (x2 < 0)
 			return;
 
-		if ((range = x2 - x1) <= 0)
+		range = x2 - x1;
+		if (range < 0)
+		{
 			return;
+		}
 
 		range++; // fencepost problem
 
+		if (range > 32767)
+		{
+			// If the range happens to be too large for fixed_t,
+			// abort the draw to avoid xscale becoming negative due to arithmetic overflow.
+			return;
+		}
+
 		scalestep = ((yscale2 - yscale)/range);
 
 		if (scalestep == 0)