diff -r 000000000000 -r 6474c204b198 gfx/cairo/ft-no-subpixel-if-surface-disables.patch
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/cairo/ft-no-subpixel-if-surface-disables.patch	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,46 @@
+# HG changeset patch
+# Parent 31c7eac3de3de324cb5c93bd19c4e16a693f1101
+# User Karl Tomlinson <karlt+@karlt.net>
+b=929451 don't use subpixel aa for ft fonts on surfaces that don't support it r?roc
+
+Also:
+* Prefer subpixel order provided by the surface over that from the font face.
+* Allow font face options to turn off subpixel aa.
+
+diff --git a/gfx/cairo/cairo/src/cairo-ft-font.c b/gfx/cairo/cairo/src/cairo-ft-font.c
+--- a/gfx/cairo/cairo/src/cairo-ft-font.c
++++ b/gfx/cairo/cairo/src/cairo-ft-font.c
+@@ -1759,23 +1759,26 @@ static void
+ 
+     if (load_flags & FT_LOAD_NO_HINTING)
+ 	other->base.hint_style = CAIRO_HINT_STYLE_NONE;
+ 
+     if (other->base.antialias == CAIRO_ANTIALIAS_NONE ||
+ 	options->base.antialias == CAIRO_ANTIALIAS_NONE) {
+ 	options->base.antialias = CAIRO_ANTIALIAS_NONE;
+ 	options->base.subpixel_order = CAIRO_SUBPIXEL_ORDER_DEFAULT;
+-    }
+-
+-    if (other->base.antialias == CAIRO_ANTIALIAS_SUBPIXEL &&
+-	(options->base.antialias == CAIRO_ANTIALIAS_DEFAULT ||
+-	 options->base.antialias == CAIRO_ANTIALIAS_GRAY)) {
+-	options->base.antialias = CAIRO_ANTIALIAS_SUBPIXEL;
+-	options->base.subpixel_order = other->base.subpixel_order;
++    } else if (options->base.antialias != CAIRO_ANTIALIAS_GRAY) {
++	/* The surface supports subpixel aa, so let the font face options
++	 * choose whether to use subpixel aa.  If the surface has
++	 * CAIRO_ANTIALIAS_GRAY (e.g. PS, PDF, SVG, translucent part of a
++	 * CONTENT_COLOR_ALPHA surface), then don't accept subpixel aa. */
++	if (other->base.antialias != CAIRO_ANTIALIAS_DEFAULT)
++	    options->base.antialias = other->base.antialias;
++	/* If the surface knows the subpixel order then use that. */
++	if (options->base.subpixel_order == CAIRO_SUBPIXEL_ORDER_DEFAULT)
++	    options->base.subpixel_order = other->base.subpixel_order;
+     }
+ 
+     if (options->base.hint_style == CAIRO_HINT_STYLE_DEFAULT)
+ 	options->base.hint_style = other->base.hint_style;
+ 
+     if (other->base.hint_style == CAIRO_HINT_STYLE_NONE)
+ 	options->base.hint_style = CAIRO_HINT_STYLE_NONE;
+