[ros-diffs] [reactos] 01/01: [WIN32K] Fix brain-fail of mine

[Jérôme Gardou]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=40f7e863472d2b0a662c06a95316997ab7c62d2b

commit 40f7e863472d2b0a662c06a95316997ab7c62d2b
Author:     Jérôme Gardou <jerome.gar...@reactos.org>
AuthorDate: Wed Mar 31 16:55:30 2021 +0200
Commit:     Jérôme Gardou <jerome.gar...@reactos.org>
CommitDate: Wed Mar 31 16:55:30 2021 +0200

    [WIN32K] Fix brain-fail of mine
    
    Copying e.g. (2;2);(6;6) to (0;0);(4;4) also needs to have an intermediate 
buffer.
---
 win32ss/gdi/dib/dib1bpp.c | 43 ++++++++++++++++++++-----------------------
 1 file changed, 20 insertions(+), 23 deletions(-)

diff --git a/win32ss/gdi/dib/dib1bpp.c b/win32ss/gdi/dib/dib1bpp.c
index 0bc25777f0c..6dcc444baec 100644
--- a/win32ss/gdi/dib/dib1bpp.c
+++ b/win32ss/gdi/dib/dib1bpp.c
@@ -69,6 +69,7 @@ DIB_1BPP_BitBltSrcCopy_From1BPP (
     LONG Width = RECTL_lGetWidth(DestRect);
     BOOLEAN XorBit = !!XLATEOBJ_iXlate(pxlo, 0);
     BOOLEAN Overlap = FALSE;
+    BYTE *DstStart, *DstEnd, *SrcStart, *SrcEnd;
 
     /* Make sure this is as expected */
     ASSERT(DestRect->left >= 0);
@@ -78,34 +79,30 @@ DIB_1BPP_BitBltSrcCopy_From1BPP (
 
     /*
      * Check if we need to allocate a buffer for our operation.
-     * NB: if we're not mirroring, we're doing a memmove-like operation, so 
this is always fine.
      */
-    if (bTopToBottom || bLeftToRight)
-    {
-        BYTE* DstStart = (BYTE*)DestSurf->pvScan0 + DestRect->top * 
DestSurf->lDelta + DestRect->left / 8;
-        BYTE* DstEnd = (BYTE*)DestSurf->pvScan0 + (DestRect->bottom - 1) * 
DestSurf->lDelta + (DestRect->right) / 8;
-        BYTE* SrcStart = (BYTE*)SourceSurf->pvScan0 + SourcePoint->y * 
SourceSurf->lDelta + SourcePoint->x / 8;
-        BYTE* SrcEnd = (BYTE*)SourceSurf->pvScan0 + (SourcePoint->y + Height - 
1) * SourceSurf->lDelta + (SourcePoint->x + Width) / 8;
+    DstStart = (BYTE*)DestSurf->pvScan0 + DestRect->top * DestSurf->lDelta + 
DestRect->left / 8;
+    DstEnd = (BYTE*)DestSurf->pvScan0 + (DestRect->bottom - 1) * 
DestSurf->lDelta + (DestRect->right) / 8;
+    SrcStart = (BYTE*)SourceSurf->pvScan0 + SourcePoint->y * 
SourceSurf->lDelta + SourcePoint->x / 8;
+    SrcEnd = (BYTE*)SourceSurf->pvScan0 + (SourcePoint->y + Height - 1) * 
SourceSurf->lDelta + (SourcePoint->x + Width) / 8;
 
-        /* Beware of bitmaps with negative pitch! */
-        if (DstStart > DstEnd)
-        {
-            BYTE* tmp = DstStart;
-            DstStart = DstEnd;
-            DstEnd = tmp;
-        }
-
-        if (SrcStart > SrcEnd)
-        {
-            BYTE* tmp = SrcStart;
-            SrcStart = SrcEnd;
-            SrcEnd = tmp;
-        }
+    /* Beware of bitmaps with negative pitch! */
+    if (DstStart > DstEnd)
+    {
+        BYTE* tmp = DstStart;
+        DstStart = DstEnd;
+        DstEnd = tmp;
+    }
 
-        /* We allocate a new buffer when the two buffers overlap */
-        Overlap = ((SrcStart >= DstStart) && (SrcStart < DstEnd)) || ((SrcEnd 
>= DstStart) && (SrcEnd < DstEnd));
+    if (SrcStart > SrcEnd)
+    {
+        BYTE* tmp = SrcStart;
+        SrcStart = SrcEnd;
+        SrcEnd = tmp;
     }
 
+    /* We allocate a new buffer when the two buffers overlap */
+    Overlap = ((SrcStart >= DstStart) && (SrcStart < DstEnd)) || ((SrcEnd >= 
DstStart) && (SrcEnd < DstEnd));
+
     if (!Overlap)
     {
         LONG y;