pixman: Branch 'master'

[Søren Sandmann Pedersen]

 pixman/pixman-utils.c |   18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

New commits:
commit e483af47db769fcba559dda72699bc80d154b575
Author: Adam Jackson <ajax at nwnk.net>
Date:   Fri May 15 06:26:48 2009 -0400

    Fix overflows during trap rasterization. [Bug 16560].
    
    Avoid overflows when rasterizing traps that fall entirely in the space
    between the final sample row and the end of the coordinate system, or
    in the space between the beginning of the coordinate system and the
    first sample row. Such traps don't contain any sample points, so the
    top and bottom of the edges can safely be moved to the beginning/end.

diff --git a/pixman/pixman-utils.c b/pixman/pixman-utils.c
index a1b7492..cdf0220 100644
--- a/pixman/pixman-utils.c
+++ b/pixman/pixman-utils.c
@@ -201,8 +201,13 @@ pixman_sample_ceil_y (pixman_fixed_t y, int n)
     f = ((f + Y_FRAC_FIRST(n)) / STEP_Y_SMALL(n)) * STEP_Y_SMALL(n) + Y_FRAC_FIRST(n);
     if (f > Y_FRAC_LAST(n))
     {
-	f = Y_FRAC_FIRST(n);
-	i += pixman_fixed_1;
+	if (pixman_fixed_to_int(i) == 0x7fff)
+	{
+	    f = 0xffff; /* saturate */
+	} else {
+	    f = Y_FRAC_FIRST(n);
+	    i += pixman_fixed_1;
+	}
     }
     return (i | f);
 }
@@ -222,8 +227,13 @@ pixman_sample_floor_y (pixman_fixed_t y, int n)
     f = _div(f - Y_FRAC_FIRST(n), STEP_Y_SMALL(n)) * STEP_Y_SMALL(n) + Y_FRAC_FIRST(n);
     if (f < Y_FRAC_FIRST(n))
     {
-	f = Y_FRAC_LAST(n);
-	i -= pixman_fixed_1;
+	if (pixman_fixed_to_int(i) == 0x8000)
+	{
+	    f = 0; /* saturate */
+	} else {
+	    f = Y_FRAC_LAST(n);
+	    i -= pixman_fixed_1;
+	}
     }
     return (i | f);
 }