SDL: render: Enable clipping for zero-sized rectangles

SDL Commits
1 
From 7207bdce5dd0a6d933937a1dab7bd762df7db6e4 Mon Sep 17 00:00:00 2001
From: Simon McVittie <[EMAIL REDACTED]>
Date: Sat, 9 Sep 2023 14:36:21 +0100
Subject: [PATCH] render: Enable clipping for zero-sized rectangles

Battle for Wesnoth apparently relies on being able to disable rendering
of UI elements by setting the clip rectangle to be empty.

Resolves: https://github.com/libsdl-org/SDL/issues/6896
Fixes: 00f05dcf "render: only enable clipping when the rectangle is valid"
Signed-off-by: Simon McVittie <smcv@collabora.com>
---
 src/render/SDL_render.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/render/SDL_render.c b/src/render/SDL_render.c
index 82fe65099e44..1df0349806d3 100644
--- a/src/render/SDL_render.c
+++ b/src/render/SDL_render.c
@@ -2534,7 +2534,7 @@ int SDL_SetRenderClipRect(SDL_Renderer *renderer, const SDL_Rect *rect)
     int retval;
     CHECK_RENDERER_MAGIC(renderer, -1)
 
-    if (rect && rect->w > 0 && rect->h > 0) {
+    if (rect && rect->w >= 0 && rect->h >= 0) {
         renderer->view->clipping_enabled = SDL_TRUE;
         renderer->view->clip_rect.x = rect->x;
         renderer->view->clip_rect.y = rect->y;