gallium: Fix region overlap conditions for rectangles with a shared edge

>From OpenGL 4.0 spec, section 4.3.2 "Copying Pixels":
"The pixels corresponding to these buffers are copied from the source
rectangle bounded by the locations (srcX0, srcY 0) and (srcX1, srcY 1)
to the destination rectangle bounded by the locations (dstX0, dstY 0)
and (dstX1, dstY 1). The lower bounds of the rectangle are inclusive,
while the upper bounds are exclusive."

So, the rectangles sharing just an edge shouldn't overlap.
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Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

diff --git a/src/gallium/auxiliary/util/u_blit.c b/src/gallium/auxiliary/util/u_blit.c
index 5bcd8bbceef821708392e3cc127b308e95f862c0..fbc9c77dfcc6bf4ac057e775fb9720428bf65832 100644 (file)
--- a/src/gallium/auxiliary/util/u_blit.c
+++ b/src/gallium/auxiliary/util/u_blit.c
@@ -314,16 +314,16 @@ regions_overlap(int srcX0, int srcY0,
                 int dstX0, int dstY0,
                 int dstX1, int dstY1)
 {
-   if (MAX2(srcX0, srcX1) < MIN2(dstX0, dstX1))
+   if (MAX2(srcX0, srcX1) <= MIN2(dstX0, dstX1))
       return FALSE; /* src completely left of dst */
 
-   if (MAX2(dstX0, dstX1) < MIN2(srcX0, srcX1))
+   if (MAX2(dstX0, dstX1) <= MIN2(srcX0, srcX1))
       return FALSE; /* dst completely left of src */
 
-   if (MAX2(srcY0, srcY1) < MIN2(dstY0, dstY1))
+   if (MAX2(srcY0, srcY1) <= MIN2(dstY0, dstY1))
       return FALSE; /* src completely above dst */
 
-   if (MAX2(dstY0, dstY1) < MIN2(srcY0, srcY1))
+   if (MAX2(dstY0, dstY1) <= MIN2(srcY0, srcY1))
       return FALSE; /* dst completely above src */
 
    return TRUE; /* some overlap */