render: Prevent division by zero if logical presentation is 0 pixels.

src/render/SDL_render.c

@@ -2571,7 +2571,12 @@ static void UpdateLogicalPresentation(SDL_Renderer *renderer)
     renderer->logical_src_rect.w = logical_w;
     renderer->logical_src_rect.h = logical_h;
 
-    if (renderer->logical_presentation_mode == SDL_LOGICAL_PRESENTATION_INTEGER_SCALE) {
+    if ((logical_w <= 0.0f) || (logical_h <= 0.0f)) {
+        renderer->logical_dst_rect.x = 0.0f;
+        renderer->logical_dst_rect.y = 0.0f;
+        renderer->logical_dst_rect.w = output_w;
+        renderer->logical_dst_rect.h = output_h;
+    } else if (renderer->logical_presentation_mode == SDL_LOGICAL_PRESENTATION_INTEGER_SCALE) {
         float scale;
         if (want_aspect > real_aspect) {
             scale = (float)((int)output_w / (int)logical_w); // This an integer division!
@@ -2635,8 +2640,8 @@ static void UpdateLogicalPresentation(SDL_Renderer *renderer)
         }
     }
 
-    renderer->main_view.logical_scale.x = (logical_w != 0.0f) ? renderer->logical_dst_rect.w / logical_w : 0.0f;
-    renderer->main_view.logical_scale.y = (logical_h != 0.0f) ? renderer->logical_dst_rect.h / logical_h : 0.0f;
+    renderer->main_view.logical_scale.x = (logical_w > 0.0f) ? renderer->logical_dst_rect.w / logical_w : 0.0f;
+    renderer->main_view.logical_scale.y = (logical_h > 0.0f) ? renderer->logical_dst_rect.h / logical_h : 0.0f;
     renderer->main_view.current_scale.x = renderer->main_view.scale.x * renderer->main_view.logical_scale.x;
     renderer->main_view.current_scale.y = renderer->main_view.scale.y * renderer->main_view.logical_scale.y;
     renderer->main_view.logical_offset.x = renderer->logical_dst_rect.x;