Don't free PalSurface when it was obtained from SDL_GetVideoSurface

Source/DiabloUI/art_draw.cpp

@@ -16,7 +16,7 @@ void UpdatePalette(Art *art, const SDL_Surface *output)
 		return;
 
 	if (output == nullptr || output->format->BitsPerPixel != 8)
-		output = pal_surface;
+		output = PalSurface;
 
 	if (SDLC_SetSurfaceColors(art->surface.get(), output->format->palette) <= -1)
 		ErrSdl();

Source/DiabloUI/diabloui.cpp

@@ -635,7 +635,7 @@ void LoadBackgroundArt(const char *pszFile, int frames)
 	BlackPalette();
 
 	SDL_FillRect(DiabloUiSurface(), nullptr, 0x000000);
-	if (DiabloUiSurface() == pal_surface)
+	if (DiabloUiSurface() == PalSurface)
 		BltFast(nullptr, nullptr);
 	RenderPresent();
 }
@@ -672,7 +672,7 @@ void UiFadeIn()
 			SetFadeLevel(fadeValue);
 	}
 
-	if (DiabloUiSurface() == pal_surface)
+	if (DiabloUiSurface() == PalSurface)
 		BltFast(nullptr, nullptr);
 	RenderPresent();
 }

Source/DiabloUI/diabloui.h

@@ -86,7 +86,7 @@ inline SDL_Surface *DiabloUiSurface()
 	// to an off-screen surface first to avoid flickering / tearing.
 	if ((output_surface->flags & SDL_HWSURFACE) != 0
 	    && (output_surface->flags & SDL_DOUBLEBUF) == 0) {
-		return pal_surface;
+		return PalSurface;
 	}
 #endif
 

Source/dx.cpp

@@ -35,9 +35,12 @@ unsigned int pal_surface_palette_version = 0;
 SDLSurfaceUniquePtr RendererTextureSurface;
 
 /** 8-bit surface that we render to */
-SDL_Surface *pal_surface;
+SDL_Surface *PalSurface;
+namespace {
+SDLSurfaceUniquePtr PinnedPalSurface;
+} // namespace
 
-/** Whether we render directly to the screen surface, i.e. `pal_surface == GetOutputSurface()` */
+/** Whether we render directly to the screen surface, i.e. `PalSurface == GetOutputSurface()` */
 bool RenderDirectlyToOutputSurface;
 
 namespace {
@@ -68,26 +71,24 @@ void CreateBackBuffer()
 {
 	if (CanRenderDirectlyToOutputSurface()) {
 		Log("{}", "Will render directly to the SDL output surface");
-		pal_surface = GetOutputSurface();
+		PalSurface = GetOutputSurface();
 		RenderDirectlyToOutputSurface = true;
 	} else {
-		pal_surface = SDL_CreateRGBSurfaceWithFormat(
+		PinnedPalSurface = SDLWrap::CreateRGBSurfaceWithFormat(
 		    /*flags=*/0,
 		    /*width=*/gnScreenWidth,
 		    /*height=*/gnScreenHeight,
 		    /*depth=*/8,
 		    SDL_PIXELFORMAT_INDEX8);
-		if (pal_surface == nullptr) {
-			ErrSdl();
-		}
+		PalSurface = PinnedPalSurface.get();
 	}
 
 #ifndef USE_SDL1
-	// In SDL2, `pal_surface` points to the global `palette`.
-	if (SDL_SetSurfacePalette(pal_surface, Palette.get()) < 0)
+	// In SDL2, `PalSurface` points to the global `palette`.
+	if (SDL_SetSurfacePalette(PalSurface, Palette.get()) < 0)
 		ErrSdl();
 #else
-	// In SDL1, `pal_surface` owns its palette and we must update it every
+	// In SDL1, `PalSurface` owns its palette and we must update it every
 	// time the global `palette` is changed. No need to do anything here as
 	// the global `palette` doesn't have any colors set yet.
 #endif
@@ -189,7 +190,7 @@ Surface GlobalBackBuffer()
 		return Surface();
 	}
 
-	return Surface(pal_surface, SDL_Rect { 0, 0, gnScreenWidth, gnScreenHeight });
+	return Surface(PalSurface, SDL_Rect { 0, 0, gnScreenWidth, gnScreenHeight });
 }
 
 void dx_cleanup()
@@ -202,10 +203,10 @@ void dx_cleanup()
 	sgdwLockCount = 0;
 	MemCrit.unlock();
 
-	if (pal_surface == nullptr)
+	if (PalSurface == nullptr)
 		return;
-	SDL_FreeSurface(pal_surface);
-	pal_surface = nullptr;
+	PalSurface = nullptr;
+	PinnedPalSurface = nullptr;
 	Palette = nullptr;
 	RendererTextureSurface = nullptr;
 #ifndef USE_SDL1
@@ -247,7 +248,7 @@ void BltFast(SDL_Rect *srcRect, SDL_Rect *dstRect)
 {
 	if (RenderDirectlyToOutputSurface)
 		return;
-	Blit(pal_surface, srcRect, dstRect);
+	Blit(PalSurface, srcRect, dstRect);
 }
 
 void Blit(SDL_Surface *src, SDL_Rect *srcRect, SDL_Rect *dstRect)
@@ -342,7 +343,7 @@ void RenderPresent()
 		ErrSdl();
 	}
 	if (RenderDirectlyToOutputSurface)
-		pal_surface = GetOutputSurface();
+		PalSurface = GetOutputSurface();
 	LimitFrameRate();
 #endif
 }

Source/dx.h

@@ -9,7 +9,7 @@
 
 namespace devilution {
 
-/** Whether we render directly to the screen surface, i.e. `pal_surface == GetOutputSurface()` */
+/** Whether we render directly to the screen surface, i.e. `PalSurface == GetOutputSurface()` */
 extern bool RenderDirectlyToOutputSurface;
 
 Surface GlobalBackBuffer();

Source/palette.cpp

@@ -163,7 +163,7 @@ void CycleColorsReverse(int from, int to)
 void palette_update(int first, int ncolor)
 {
 	assert(Palette);
-	if (SDLC_SetSurfaceAndPaletteColors(pal_surface, Palette.get(), system_palette, first, ncolor) < 0) {
+	if (SDLC_SetSurfaceAndPaletteColors(PalSurface, Palette.get(), system_palette, first, ncolor) < 0) {
 		ErrSdl();
 	}
 	pal_surface_palette_version++;

Source/scrollrt.cpp

@@ -1552,14 +1552,14 @@ void CalcViewportGeometry()
 	tileRows++; // Cover lower edge saw tooth, right edge accounted for in scrollrt_draw()
 }
 
-extern SDL_Surface *pal_surface;
+extern SDL_Surface *PalSurface;
 
 void ClearScreenBuffer()
 {
 	lock_buf(3);
 
-	assert(pal_surface != nullptr);
-	SDL_FillRect(pal_surface, nullptr, 0);
+	assert(PalSurface != nullptr);
+	SDL_FillRect(PalSurface, nullptr, 0);
 
 	unlock_buf(3);
 }

Source/utils/display.h

@@ -23,7 +23,7 @@ extern SDLTextureUniquePtr texture;
 #endif
 
 extern SDLPaletteUniquePtr Palette;
-extern SDL_Surface *pal_surface;
+extern SDL_Surface *PalSurface;
 extern unsigned int pal_surface_palette_version;
 
 #ifdef USE_SDL1