From 5668bf7c35e6bb050ec951db8ee142a446d4f6bd Mon Sep 17 00:00:00 2001
From: narzoul <narzoul@users.noreply.github.com>
Date: Fri, 14 Jul 2017 11:31:55 +0200
Subject: [PATCH] Repaint scrolled area when smooth scrolling is disabled

When the SW_SMOOTHSCROLL flag is removed in ScrollWindowEx, it needs to be
replaced with SW_ERASE and SW_INVALIDATE to properly repaint the scrolled
portions of the window.

Fixes an issue reported in #16.
---
 DDrawCompat/Gdi/ScrollFunctions.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/DDrawCompat/Gdi/ScrollFunctions.cpp b/DDrawCompat/Gdi/ScrollFunctions.cpp
index 9e6b19d..1bd735f 100644
--- a/DDrawCompat/Gdi/ScrollFunctions.cpp
+++ b/DDrawCompat/Gdi/ScrollFunctions.cpp
@@ -27,7 +27,7 @@ namespace
 
 		if (flags & SW_SMOOTHSCROLL)
 		{
-			flags = LOWORD(flags ^ SW_SMOOTHSCROLL);
+			flags = (LOWORD(flags) & ~SW_SMOOTHSCROLL) | SW_INVALIDATE | SW_ERASE;
 		}
 
 		int result = CALL_ORIG_FUNC(ScrollWindowEx)(