From 81eb438482f176526e7d4e0de6d21be49580a27a Mon Sep 17 00:00:00 2001
From: Clownacy <Clownacy@users.noreply.github.com>
Date: Tue, 16 Jul 2019 00:15:20 +0100
Subject: [PATCH] Fixes and tweaks

---
 src/Backends/Rendering/SDLTexture.cpp |  4 +++-
 src/Backends/Rendering/Software.cpp   | 12 ++++++++++++
 src/Draw.cpp                          |  8 ++++----
 src/Main.cpp                          |  1 -
 4 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/Backends/Rendering/SDLTexture.cpp b/src/Backends/Rendering/SDLTexture.cpp
index 852fd519..ddc74248 100644
--- a/src/Backends/Rendering/SDLTexture.cpp
+++ b/src/Backends/Rendering/SDLTexture.cpp
@@ -86,6 +86,7 @@ BOOL Backend_Init(SDL_Window *window)
 
 void Backend_Deinit(void)
 {
+	SDL_DestroyTexture(screen_texture);
 	SDL_DestroyRenderer(renderer);
 }
 
@@ -126,9 +127,10 @@ Backend_Surface* Backend_CreateSurface(unsigned int width, unsigned int height)
 	surface->needs_syncing = FALSE;
 
 	surface->next = surface_list_head;
+	surface->prev = NULL;
+	surface_list_head = surface;
 	if (surface->next)
 		surface->next->prev = surface;
-	surface_list_head = surface;
 
 	return surface;
 }
diff --git a/src/Backends/Rendering/Software.cpp b/src/Backends/Rendering/Software.cpp
index 8ae95281..4978c018 100644
--- a/src/Backends/Rendering/Software.cpp
+++ b/src/Backends/Rendering/Software.cpp
@@ -130,6 +130,12 @@ void Backend_Blit(Backend_Surface *source_surface, const RECT *rect, Backend_Sur
 		rect_clamped.bottom -= overflow;
 	}
 
+	if (rect_clamped.bottom - rect_clamped.top <= 0)
+		return;
+
+	if (rect_clamped.right - rect_clamped.left <= 0)
+		return;
+
 	// Do the actual blitting
 	if (colour_key)
 	{
@@ -205,6 +211,12 @@ void Backend_ColourFill(Backend_Surface *surface, const RECT *rect, unsigned cha
 		rect_clamped.bottom -= overflow;
 	}
 
+	if (rect_clamped.bottom - rect_clamped.top <= 0)
+		return;
+
+	if (rect_clamped.right - rect_clamped.left <= 0)
+		return;
+
 	for (long j = 0; j < rect_clamped.bottom - rect_clamped.top; ++j)
 	{
 		unsigned char *source_pointer = &surface->pixels[((rect_clamped.top + j) * surface->pitch) + (rect_clamped.left * 3)];
diff --git a/src/Draw.cpp b/src/Draw.cpp
index 3bf6c3da..283a97af 100644
--- a/src/Draw.cpp
+++ b/src/Draw.cpp
@@ -92,24 +92,24 @@ BOOL StartDirectDraw(int lMagnification, int lColourDepth)
 			break;
 	}
 
+	rgb24_pixel_format = SDL_AllocFormat(SDL_PIXELFORMAT_RGB24);
+
 	// Create renderer
 	if (!Backend_Init(gWindow))
 		return FALSE;
 
-	rgb24_pixel_format = SDL_AllocFormat(SDL_PIXELFORMAT_RGB24);
-
 	return TRUE;
 }
 
 void EndDirectDraw()
 {
-	SDL_FreeFormat(rgb24_pixel_format);
-
 	// Release all surfaces
 	for (int i = 0; i < SURFACE_ID_MAX; i++)
 		ReleaseSurface(i);
 
 	Backend_Deinit();
+
+	SDL_FreeFormat(rgb24_pixel_format);
 }
 
 static BOOL IsEnableBitmap(SDL_RWops *fp)
diff --git a/src/Main.cpp b/src/Main.cpp
index f3b98f7a..171eca8d 100644
--- a/src/Main.cpp
+++ b/src/Main.cpp
@@ -298,7 +298,6 @@ int main(int argc, char *argv[])
 
 					StartDirectDraw(2, colourDepth);
 
-					fullscreen = TRUE;
 					SDL_ShowCursor(0);
 					break;
 				}