[reactos] 01/01: [GDI32] GdiDrawStream: Improve handling of small rcDest sizes - Abort drawing if rcDest has negative height or width. - Ignore sizing margins if rcDest is too small. CORE-13513

[Giannis Adamopoulos]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=febf9acfeeb71ae6fca7c3...

commit febf9acfeeb71ae6fca7c3a659449ef7997458fa
Author: Giannis Adamopoulos [e-mail]
AuthorDate: Wed Nov 22 17:28:18 2017 +0200

[GDI32] GdiDrawStream: Improve handling of small rcDest sizes
    - Abort drawing if rcDest has negative height or width.
    - Ignore sizing margins if rcDest is too small.
    CORE-13513
---
 win32ss/gdi/gdi32/misc/misc.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/win32ss/gdi/gdi32/misc/misc.c b/win32ss/gdi/gdi32/misc/misc.c
index 65287d0b1d..6675e7335c 100644
--- a/win32ss/gdi/gdi32/misc/misc.c
+++ b/win32ss/gdi/gdi32/misc/misc.c
@@ -677,6 +677,19 @@ GdiDrawStream(HDC dc, ULONG l, PGDI_DRAW_STREAM pDS)
         else
             sizingtype = ST_STRETCH;

+        if (pDS->rcDest.right < pDS->rcDest.left || pDS->rcDest.bottom < pDS->rcDest.top)
+            return 0;
+
+        if (sm.cxLeftWidth + sm.cxRightWidth > pDS->rcDest.right - pDS->rcDest.left)
+        {
+            sm.cxLeftWidth = sm.cxRightWidth = 0;
+        }
+
+        if (sm.cyTopHeight + sm.cyBottomHeight > pDS->rcDest.bottom - pDS->rcDest.top)
+        {
+            sm.cyTopHeight = sm.cyBottomHeight = 0;
+        }
+
         UXTHEME_DrawImageBackground(pDS->hDC, 
                                     pDS->hImage, 
                                     &pDS->rcSrc,