SDL: Set an error message if the rect passed to SDL_RenderReadPixels() is entirely outside the viewport

SDL Commits
1 
From 85a302550d98c703adf29c4db7892b278cad9913 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Tue, 25 Feb 2025 10:27:05 -0800
Subject: [PATCH] Set an error message if the rect passed to
 SDL_RenderReadPixels() is entirely outside the viewport

---
 src/render/SDL_render.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/render/SDL_render.c b/src/render/SDL_render.c
index 52f0b38257ae9..0622a52c1c053 100644
--- a/src/render/SDL_render.c
+++ b/src/render/SDL_render.c
@@ -5019,6 +5019,7 @@ SDL_Surface *SDL_RenderReadPixels(SDL_Renderer *renderer, const SDL_Rect *rect)
 
     if (rect) {
         if (!SDL_GetRectIntersection(rect, &real_rect, &real_rect)) {
+            SDL_SetError("Can't read outside the current viewport");
             return NULL;
         }
     }