From ab72bc06d69b8908435c21c9d4b907e109d4c7db Mon Sep 17 00:00:00 2001
From: Ryan Kounter <ryan@kounter.net>
Date: Sat, 27 Apr 2024 11:56:03 -0400
Subject: [PATCH] [COMCTL32] Fix header redraw glitches when resizing (#6799)

Fixes COMCTL32 headers from being garbage text when resizing while drawn off screen.

- Invalidate header item rect before scrolling to prevent the divider from being redrawn over and over.
- Invalidate header item text through adding flag SW_INVALIDATE to ScrollWindowEx call to prevent the text from being redrawn over and over.

CORE-19404
---
 dll/win32/comctl32/header.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/dll/win32/comctl32/header.c b/dll/win32/comctl32/header.c
index a48530d8882..e72324ce1f1 100644
--- a/dll/win32/comctl32/header.c
+++ b/dll/win32/comctl32/header.c
@@ -1948,13 +1948,21 @@ HEADER_MouseMove (HEADER_INFO *infoPtr, LPARAM lParam)
                     
                     if (nWidth < 0) nWidth = 0;
                     infoPtr->items[infoPtr->iMoveItem].cxy = nWidth;
+#ifdef __REACTOS__
+                    InvalidateRect(infoPtr->hwndSelf, &lpItem->rect, FALSE);
+#endif
                     HEADER_SetItemBounds(infoPtr);
                     
                     GetClientRect(infoPtr->hwndSelf, &rcClient);
                     rcScroll = rcClient;
                     rcScroll.left = lpItem->rect.left + nOldWidth;
+#ifdef __REACTOS__
+                    ScrollWindowEx(infoPtr->hwndSelf, nWidth - nOldWidth, 0, &rcScroll, &rcClient,
+                                   NULL, NULL, SW_INVALIDATE);
+#else
                     ScrollWindowEx(infoPtr->hwndSelf, nWidth - nOldWidth, 0, &rcScroll, &rcClient, NULL, NULL, 0);
                     InvalidateRect(infoPtr->hwndSelf, &lpItem->rect, FALSE);
+#endif
                     UpdateWindow(infoPtr->hwndSelf);
                     
                     HEADER_SendNotifyWithIntFieldT(infoPtr, HDN_ITEMCHANGEDW, infoPtr->iMoveItem, HDI_WIDTH, nWidth);