test: Add example from bug-51910

The calculation of the required source extents blows up under xlib.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

3 files changed, 92 insertions, 0 deletions

diff --git a/test/Makefile.sources b/test/Makefile.sources
index 309cf0715..8975b468d 100644
--- a/test/Makefile.sources
+++ b/test/Makefile.sources
@@ -25,6 +25,7 @@ test_sources = \
 	big-trap.c					\
 	bilevel-image.c					\
 	bug-40410.c					\
+	bug-51910.c					\
 	bug-bo-rectangular.c				\
 	bug-bo-collins.c				\
 	bug-bo-ricotz.c					\
diff --git a/test/bug-51910.c b/test/bug-51910.c
new file mode 100644
index 000000000..37881de3e
--- /dev/null
+++ b/test/bug-51910.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * 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.
+ */
+
+#include "cairo-test.h"
+
+/* An error in xlib pattern transformation discovered by Albertas Vyšniauskas */
+
+static cairo_pattern_t *
+source(void)
+{
+    cairo_surface_t *surface;
+    cairo_pattern_t *pattern;
+    cairo_matrix_t matrix;
+    cairo_t *cr;
+    int i;
+
+    surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, 32, 32);
+    cr = cairo_create (surface);
+    cairo_surface_destroy (surface);
+
+    cairo_set_source_rgb (cr, 1, 1, 1);
+    cairo_paint (cr);
+
+    cairo_set_source_rgb (cr, .5, .5, .5);
+    cairo_set_line_width (cr, 2);
+
+    for (i = -1; i <= 8; i++) {
+	cairo_move_to (cr, -34 + 8*i, 34);
+	cairo_rel_line_to (cr, 36, -36);
+	cairo_stroke (cr);
+    }
+
+    pattern = cairo_pattern_create_for_surface (cairo_get_target (cr));
+    cairo_destroy (cr);
+
+    cairo_pattern_set_extend (pattern, CAIRO_EXTEND_REPEAT);
+
+    cairo_matrix_init_translate(&matrix, 14.1, 0);
+    cairo_pattern_set_matrix(pattern, &matrix);
+
+    return pattern;
+}
+
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_pattern_t *pattern;
+    int i;
+
+    cairo_paint (cr);
+
+    pattern = source ();
+    cairo_set_source (cr, pattern);
+    cairo_pattern_destroy (pattern);
+
+    for (i = 0; i < 8; i++) {
+	cairo_rectangle (cr, 3.5*i, 32*i, 256, 32);
+	cairo_fill (cr);
+    }
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (bug_51910,
+	    "A bug in the xlib pattern transformation",
+	    " paint", /* keywords */
+	    NULL, /* requirements */
+	    256, 256,
+	    NULL, draw)
diff --git a/test/reference/bug-51910.ref.png b/test/reference/bug-51910.ref.png
new file mode 100644
index 000000000..7f55eaae5
--- /dev/null
+++ b/test/reference/bug-51910.ref.png