test: Test downscaling and extending a surface pattern.

Franz Schmid reported a regression in 1.9.6 when downscaling
and using EXTEND_REPEAT for an image surface pattern.  This
patch adds such tests for every extend mode.

test/Makefile.sources

@@ -226,6 +226,7 @@ test_sources = \
 	surface-pattern-big-scale-down.c		\
 	surface-pattern-operator.c			\
 	surface-pattern-scale-down.c			\
+	surface-pattern-scale-down-extend.c		\
 	surface-pattern-scale-up.c			\
 	text-antialias-gray.c				\
 	text-antialias-none.c				\

test/surface-pattern-scale-down-extend.c

@@ -0,0 +1,107 @@
+/*
+ * Copyright © 2010 M Joonas Pihlaja
+ *
+ * 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: M Joonas Pihlaja <jpihlaja@cc.helsinki.fi>
+ */
+#include "cairo-test.h"
+
+/* Test that we can simultaneously downscale and extend a surface
+ * pattern.  Reported by Franz Schmid to the cairo mailing list as a
+ * regression in 1.9.6:
+ *
+ * http://lists.cairographics.org/archives/cairo/2010-February/019492.html
+ */
+
+static cairo_test_status_t
+draw_with_extend (cairo_t *cr, int w, int h, cairo_extend_t extend)
+{
+    cairo_pattern_t *pattern;
+    cairo_set_source_rgb (cr, 1,1,1);
+    cairo_paint (cr);
+
+    cairo_push_group_with_content (cr, CAIRO_CONTENT_COLOR); {
+        /* A two by two checkerboard with black, red and yellow
+         * cells. */
+        cairo_set_source_rgb (cr, 1,0,0);
+        cairo_rectangle (cr, w/2, 0, w-w/2, h/2);
+        cairo_fill (cr);
+        cairo_set_source_rgb (cr, 1,1,0);
+        cairo_rectangle (cr, 0, h/2, w/2, h-h/2);
+        cairo_fill (cr);
+    }
+    pattern = cairo_pop_group (cr);
+    cairo_pattern_set_extend(pattern, extend);
+
+    cairo_scale (cr, 0.5, 0.5);
+    cairo_set_source (cr, pattern);
+    cairo_paint (cr);
+
+    cairo_pattern_destroy (pattern);
+    return CAIRO_TEST_SUCCESS;
+}
+
+static cairo_test_status_t
+draw_repeat (cairo_t *cr, int w, int h)
+{
+    return draw_with_extend (cr, w, h, CAIRO_EXTEND_REPEAT);
+}
+static cairo_test_status_t
+draw_none (cairo_t *cr, int w, int h)
+{
+    return draw_with_extend (cr, w, h, CAIRO_EXTEND_NONE);
+}
+static cairo_test_status_t
+draw_reflect (cairo_t *cr, int w, int h)
+{
+    return draw_with_extend (cr, w, h, CAIRO_EXTEND_REFLECT);
+}
+static cairo_test_status_t
+draw_pad (cairo_t *cr, int w, int h)
+{
+    return draw_with_extend (cr, w, h, CAIRO_EXTEND_PAD);
+}
+
+CAIRO_TEST (surface_pattern_scale_down_extend_repeat,
+	    "Test interaction of downscaling a surface pattern and extend-repeat",
+            "pattern, transform, extend", /* keywords */
+	    NULL, /* requirements */
+            100, 100,
+	    NULL, draw_repeat)
+CAIRO_TEST (surface_pattern_scale_down_extend_none,
+	    "Test interaction of downscaling a surface pattern and extend-none",
+            "pattern, transform, extend", /* keywords */
+	    NULL, /* requirements */
+            100, 100,
+	    NULL, draw_none)
+CAIRO_TEST (surface_pattern_scale_down_extend_reflect,
+	    "Test interaction of downscaling a surface pattern and extend-reflect",
+            "pattern, transform, extend", /* keywords */
+	    NULL, /* requirements */
+            100, 100,
+	    NULL, draw_reflect)
+CAIRO_TEST (surface_pattern_scale_down_extend_pad,
+	    "Test interaction of downscaling a surface pattern and extend-pad",
+            "pattern, transform, extend", /* keywords */
+	    NULL, /* requirements */
+            100, 100,
+	    NULL, draw_pad)