From e40b261ed967d3580307f2433ad9a57f011c8ec1 Mon Sep 17 00:00:00 2001 From: James Tabor Date: Fri, 26 Oct 2007 02:07:33 +0000 Subject: [PATCH] ScrollDC From my notes 08/16/2003: - Wine testing was not enough. If dx & dy are zero and hrgn and lprc are used or not zero. The Rect for hrgn and lprc are set zero w/o NtUserScrollDC being called. It just returns TRUE. - If HDC is zero it will return FALSE and not call NtUserScrollDC. svn path=/trunk/; revision=29893 --- reactos/dll/win32/user32/windows/paint.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/reactos/dll/win32/user32/windows/paint.c b/reactos/dll/win32/user32/windows/paint.c index d79ea687413..c2cf5623c82 100644 --- a/reactos/dll/win32/user32/windows/paint.c +++ b/reactos/dll/win32/user32/windows/paint.c @@ -185,6 +185,16 @@ BOOL STDCALL ScrollDC(HDC hDC, int dx, int dy, CONST RECT *lprcScroll, CONST RECT *lprcClip, HRGN hrgnUpdate, LPRECT lprcUpdate) { + if (hDC == NULL) return FALSE; + + if (dx == 0 && dy == 0) + { + if (hrgnUpdate) SetRectRgn(hrgnUpdate, 0, 0, 0, 0); + if (lprcUpdate) lprcUpdate->left = lprcUpdate->right = + lprcUpdate->top = lprcUpdate->bottom = 0; + return TRUE; + } + return NtUserScrollDC(hDC, dx, dy, lprcScroll, lprcClip, hrgnUpdate, lprcUpdate); }