[1/2] richedit: Clip painting to formatting rectangle (try 2)

[Dylan Smith]

I realized after my patch wasn't accepted that I probably didn't handle
the case were no clip region was retrived by GetClipRgn properly, so I
corrected my patch to handle this case.

I also checked other places GetClipRgn was used in wine code, and used
similar code in winefile as a reference for setting the clip region
properly.
---
 dlls/riched20/paint.c |   18 +++++++++++++++++-
 1 files changed, 17 insertions(+), 1 deletions(-)
-------------- next part --------------
diff --git a/dlls/riched20/paint.c b/dlls/riched20/paint.c
index b6430e4..d58ea41 100644
--- a/dlls/riched20/paint.c
+++ b/dlls/riched20/paint.c
@@ -29,6 +29,17 @@ void ME_PaintContent(ME_TextEditor *editor, HDC hDC, BOOL bOnlyNew, const RECT *
   ME_Context c;
   int yoffset;
   int ys, ye;
+  HRGN oldRgn, clipRgn;
+
+  oldRgn = CreateRectRgn(0, 0, 0, 0);
+  if (!GetClipRgn(hDC, oldRgn))
+  {
+    DeleteObject(oldRgn);
+    oldRgn = NULL;
+  }
+  clipRgn = CreateRectRgnIndirect(rcUpdate);
+  ExtSelectClipRgn(hDC, clipRgn, RGN_AND);
+  DeleteObject(clipRgn);
 
   editor->nSequence++;
   yoffset = ME_GetYScrollPos(editor);
@@ -105,6 +116,10 @@ void ME_PaintContent(ME_TextEditor *editor, HDC hDC, BOOL bOnlyNew, const RECT *
     ME_SendRequestResize(editor, FALSE);
   editor->nLastTotalLength = editor->nTotalLength;
   ME_DestroyContext(&c, NULL);
+
+  SelectClipRgn(hDC, oldRgn);
+  if (oldRgn)
+    DeleteObject(oldRgn);
 }
 
 void ME_Repaint(ME_TextEditor *editor)
@@ -1050,7 +1065,8 @@ void ME_Scroll(ME_TextEditor *editor, int value, int type)
   if (abs(nActualScroll) > editor->sizeWindow.cy)
     InvalidateRect(editor->hWnd, NULL, TRUE);
   else
-    ScrollWindowEx(editor->hWnd, 0, nActualScroll, NULL, NULL, NULL, NULL, SW_INVALIDATE);
+    ScrollWindowEx(editor->hWnd, 0, nActualScroll, &editor->rcFormat,
+                   &editor->rcFormat, NULL, NULL, SW_INVALIDATE);
   ME_Repaint(editor);
   
   hWnd = editor->hWnd;