https://bugs.gentoo.org/811501
https://sourceforge.net/p/ri-li/bugs/2/

From 317a80608a061a0acdf196a6c148bfe63b1eaad5 Mon Sep 17 00:00:00 2001
From: Sergei Trofimovich <slyich@gmail.com>
Date: Thu, 21 Apr 2022 07:52:46 +0100
Subject: [PATCH] Fix build on gcc-11

Without the change build fails on ordered comparison on pointers:

tableau.cc:90:9: error: ordered comparison of pointer with integer zero ('unsigned char*' and 'int')
   90 |   if(Buf<=0) return false;
      |      ~~~^~~
--- a/src/sprite.cc
+++ b/src/sprite.cc
@@ -351,7 +351,7 @@ bool Sprite::Load(unsigned char *Buf,long &P)
     // Fabrique la surface
     Image[i]=SDL_CreateRGBSurface((Dim[i].bpp-3)*SDL_SRCALPHA,Dim[i].L,Dim[i].H,Dim[i].bpp*8,
 				  0xff,0xff00,0xff0000,0xff000000*(Dim[i].bpp-3));
-    if(Image[i]<=NULL) {
+    if(Image[i]==NULL) {
       std::cerr <<"Impossible de créer une Surface SDL!"<<std::endl;
       return false;
     }
@@ -485,7 +485,7 @@ bool Sprite::Nouveau(int Lx,int Ly)
   // Fabrique la surface
   Image[0]=SDL_CreateRGBSurface((Dim[0].bpp-3)*SDL_SRCALPHA,Dim[0].L,Dim[0].H,Dim[0].bpp*8,
 				0xff,0xff00,0xff0000,0xff000000*(Dim[0].bpp-3));
-  if(Image[0]<=NULL) {
+  if(Image[0]==NULL) {
     std::cerr <<"Impossible de créer une Surface SDL!"<<std::endl;
     return false;
   }
--- a/src/tableau.cc
+++ b/src/tableau.cc
@@ -87,7 +87,7 @@ bool Tableau::Save(void)
   
   // Alloue la mémoire
   Buf=new unsigned char [sizeof(s_Tableau)*N+sizeof(int)+1];
-  if(Buf<=0) return false;
+  if(Buf==NULL) return false;
 
   // Charge les tableaux
   Buf[0]=N/256;
-- 
2.35.1