[cairo-commit] src/cairo-scaled-font.c

[M. Joonas Pihlaja]

 src/cairo-scaled-font.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

New commits:
commit 75db4f0ece194b7aa0455509785a300784778ec4
Author: M Joonas Pihlaja <jpihlaja at cc.helsinki.fi>
Date:   Mon Feb 22 02:26:47 2010 +0200

    text: Fix assert failure from compositing by SOURCE with a mask internally.
    
    Change the operator used to upgrade the format of a glyph mask from
    CAIRO_OPERATOR_SOURCE to CAIRO_OPERATOR_ADD.
    
    The _cairo_scaled_font_show_glyphs() function upgrades the pixel
    format of a glyph mask by calling _cairo_surface_composite() to copy
    the mask to an image surface of the upgraded destination.  The way it
    was doing it however was to use CAIRO_OPERATOR_SOURCE, a white source
    pattern and the glyph's rasterised glyph as the mask pattern.  This
    combination isn't supported by _cairo_surface_composite(), which
    asserts that no mask is present when the operator is SOURCE or CLEAR.
    
    Reported by Mikael Magnusson to #cairo on irc.freenode.net.

diff --git a/src/cairo-scaled-font.c b/src/cairo-scaled-font.c
index 7a556a7..480488f 100644
--- a/src/cairo-scaled-font.c
+++ b/src/cairo-scaled-font.c
@@ -2163,7 +2163,7 @@ _cairo_scaled_font_show_glyphs (cairo_scaled_font_t	*scaled_font,
 	    /* Note that we only upgrade masks, i.e. A1 -> A8 -> ARGB32, so there is
 	     * never any component alpha here.
 	     */
-	    status = _cairo_surface_composite (CAIRO_OPERATOR_SOURCE,
+	    status = _cairo_surface_composite (CAIRO_OPERATOR_ADD,
 					       &_cairo_pattern_white.base,
 					       &mask_pattern.base,
 					       new_mask,