From 2fa2a9480a72ac9e4e21a63d97fa83feda816546 Mon Sep 17 00:00:00 2001
From: Mingjie Shen <shen497@purdue.edu>
Date: Tue, 13 Feb 2024 14:02:31 -0500
Subject: [PATCH] Fix undefined behavior of signed integer overflow

Testing for overflow by adding a value to a variable to see if it "wraps
around" works only for unsigned integer values. Signed integer overflow
is undefined behavior in C and C++.
---
 tests/tearing.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tests/tearing.c b/tests/tearing.c
index 5c7893c2..293c7af7 100644
--- a/tests/tearing.c
+++ b/tests/tearing.c
@@ -36,6 +36,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
+#include <limits.h>
 
 #include "linmath.h"
 
@@ -103,7 +104,7 @@ static void key_callback(GLFWwindow* window, int key, int scancode, int action,
     {
         case GLFW_KEY_UP:
         {
-            if (swap_interval + 1 > swap_interval)
+            if (swap_interval <= INT_MAX - 1)
                 set_swap_interval(window, swap_interval + 1);
             break;
         }
@@ -112,12 +113,12 @@ static void key_callback(GLFWwindow* window, int key, int scancode, int action,
         {
             if (swap_tear)
             {
-                if (swap_interval - 1 < swap_interval)
+                if (swap_interval >= INT_MIN + 1)
                     set_swap_interval(window, swap_interval - 1);
             }
             else
             {
-                if (swap_interval - 1 >= 0)
+                if (swap_interval >= 1)
                     set_swap_interval(window, swap_interval - 1);
             }
             break;