test: Add gradient-zero-stops-mask

Add a test to check that gradient with no stops are not considered
opaque by gstate (and thus masking with them is not optimized to
paint).

test/Makefile.am

@@ -540,6 +540,8 @@ REFERENCE_IMAGES = \
 	gradient-constant-alpha.rgb24.ref.png \
 	gradient-zero-stops.ref.png \
 	gradient-zero-stops.rgb24.ref.png \
+	gradient-zero-stops-mask.argb32.ref.png \
+	gradient-zero-stops-mask.rgb24.ref.png \
 	group-clip.ref.png \
 	group-paint.ref.png \
 	group-unaligned.pdf.new.png \

test/Makefile.sources

@@ -106,6 +106,7 @@ test_sources = \
 	gradient-alpha.c				\
 	gradient-constant-alpha.c			\
 	gradient-zero-stops.c				\
+	gradient-zero-stops-mask.c			\
 	group-clip.c					\
 	group-paint.c					\
 	group-unaligned.c				\

test/gradient-zero-stops-mask.c

@@ -0,0 +1,59 @@
+/* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
+/*
+ * Copyright © 2007 Brian Ewins
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Author: Brian Ewins <Brian.Ewins@gmail.com>
+ * Contributor(s):
+ *      Andrea Canciani <ranma42@gmail.com>
+ */
+
+#include "cairo-test.h"
+
+/* This test case is designed to exercise the opaque test for
+ * gradients with no stop.
+ */
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_pattern_t *pat;
+
+    cairo_set_source_rgb (cr, 1., 0., 0.);
+
+    pat = cairo_pattern_create_linear (0., 0., 1., 1.);
+    cairo_mask (cr, pat);
+    cairo_pattern_destroy (pat);
+
+    pat = cairo_pattern_create_radial (0., 0., 0., 1., 1., 1.);
+    cairo_mask (cr, pat);
+    cairo_pattern_destroy (pat);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (gradient_zero_stops_mask,
+	    "Verifies that gradients with no stops are considered clear.",
+	    "gradient", /* keywords */
+	    NULL, /* requirements */
+	    2, 2,
+	    NULL, draw)