GPU: Fix crash when trying to postprocess surfaceless

src/core/gpu.cpp

@@ -1716,8 +1716,10 @@ bool GPU::RenderDisplay(GPUTexture* target, const Common::Rectangle<s32>& draw_r
   const GPUTexture::Format hdformat = target ? target->GetFormat() : g_gpu_device->GetWindowFormat();
   const u32 target_width = target ? target->GetWidth() : g_gpu_device->GetWindowWidth();
   const u32 target_height = target ? target->GetHeight() : g_gpu_device->GetWindowHeight();
-  const bool really_postfx = (postfx && HasDisplayTexture() && PostProcessing::IsActive() &&
-                              PostProcessing::CheckTargets(hdformat, target_width, target_height));
+  const bool really_postfx =
+    (postfx && HasDisplayTexture() && PostProcessing::IsActive() && !g_gpu_device->GetWindowInfo().IsSurfaceless() &&
+     hdformat != GPUTexture::Format::Unknown && target_width > 0 && target_height > 0 &&
+     PostProcessing::CheckTargets(hdformat, target_width, target_height));
   const Common::Rectangle<s32> real_draw_rect =
     g_gpu_device->UsesLowerLeftOrigin() ? GPUDevice::FlipToLowerLeft(draw_rect, target_height) : draw_rect;
   if (really_postfx)

src/util/postprocessing.cpp

@@ -681,6 +681,7 @@ bool PostProcessing::CheckTargets(GPUTexture::Format target_format, u32 target_w
       !(s_output_texture = g_gpu_device->FetchTexture(target_width, target_height, 1, 1, 1,
                                                       GPUTexture::Type::RenderTarget, target_format)))
   {
+    DestroyTextures();
     return false;
   }