sdl2-compat: Make SDL2Compat_strlen return size_t

SDL Commits
1 
From bdb1e9d362d1e3ccb34567da29eb35af394b6378 Mon Sep 17 00:00:00 2001
From: Simon McVittie <[EMAIL REDACTED]>
Date: Mon, 15 Jun 2026 12:10:49 +0100
Subject: [PATCH] Make SDL2Compat_strlen return size_t

This gives it the same signature as Standard C strlen(), and avoids the
possibility of signed integer overflow.

Signed-off-by: Simon McVittie <smcv@collabora.com>
---
 src/sdl2_compat.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/sdl2_compat.c b/src/sdl2_compat.c
index 8f0db91a..b6d1cada 100644
--- a/src/sdl2_compat.c
+++ b/src/sdl2_compat.c
@@ -270,7 +270,7 @@ SDL2COMPAT_itoa(char *dst, int val)
 }
 
 /* you can use SDL3_strlen once we're past startup. */
-static int SDL2Compat_strlen(const char *str)
+static size_t SDL2Compat_strlen(const char *str)
 {
     /* volatile prevents gcc from optimizing this into a call to the
      * strlen() library function, which we are intentionally avoiding on
@@ -279,7 +279,7 @@ static int SDL2Compat_strlen(const char *str)
     while (*ptr) {
         ++ptr;
     }
-    return (int)(ptr - str);
+    return (size_t)(ptr - str);
 }
 
 /* you can use SDL3_strcmp once we're past startup. */
@@ -898,7 +898,7 @@ SDL2Compat_ApplyQuirks(bool force_x11)
     if (WantDebugLogging) {
         const char *lead = "sdl2-compat: This app appears to be named:";
         char msg[256];
-        if ((SDL2Compat_strlen(lead) + SDL2Compat_strlen(exe_name) + 2) <= (int) (sizeof (msg))) {
+        if ((SDL2Compat_strlen(lead) + SDL2Compat_strlen(exe_name) + 2) <= sizeof (msg)) {
             char *p = msg;
             p = SDL2COMPAT_stpcpy(p, lead);
             p = SDL2COMPAT_stpcpy(p, " ");