From 55f18d362568cf20a46df20ff597583e665717d3 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Sat, 16 Mar 2019 18:45:10 -0700
Subject: [PATCH] Fixed bug 4544 - SDL2.m4 SDL2.framework patch made it
 impossible to fail detection

Stian Skjelstad

check if $sdl_framework is set, before checking if directory exists

Patch that was merged here https://hg.libsdl.org/SDL/rev/ad4968de54ec made it impossible for the SDL2 detection to fail, since one of the if statements fails to check if a variable is set or not.

if test -d $sdl_framework; then

can evaluate to true in some shells. I guess it falls into undefined behaviour when looking at the POSIX standard.
---
 sdl2.m4 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sdl2.m4 b/sdl2.m4
index b915f99edec28..0a73bc7d476a3 100644
--- a/sdl2.m4
+++ b/sdl2.m4
@@ -74,7 +74,7 @@ AC_ARG_VAR(SDL2_FRAMEWORK, [Path to SDL2.framework])
         done
       fi
 
-      if test -d $sdl_framework; then
+      if test x"$sdl_framework" != x && test -d "$sdl_framework"; then
         AC_MSG_RESULT($sdl_framework)
         sdl_framework_dir=`dirname $sdl_framework`
         SDL_CFLAGS="-F$sdl_framework_dir -Wl,-framework,SDL2 -I$sdl_framework/include"