test: Add clip-push-group to demonstrate crash in cairo_push_group

The crash happens anytime mask-based clipping is in effect
at the time of cairo_push_group. The crash was first reported
here:
	http://lists.freedesktop.org/archives/cairo/2006-August/007698.html

1 files changed, 74 insertions, 0 deletions

diff --git a/test/clip-push-group.c b/test/clip-push-group.c
new file mode 100644
index 000000000..f18d13c77
--- /dev/null
+++ b/test/clip-push-group.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright © 2006 Red Hat, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Red Hat, Inc. not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Red Hat, Inc. makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Carl D. Worth <cworth@cworth.org>
+ */
+
+/* A test for the crash described here:
+ *
+ *	http://lists.freedesktop.org/archives/cairo/2006-August/007698.html
+ *
+ * The triggering condition for this bug should be setting a
+ * surface-based clip and then calling cairo_push_group.
+ */
+
+#include "cairo-test.h"
+
+#define SIZE 10
+
+static cairo_test_draw_function_t draw;
+
+cairo_test_t test = {
+    "clip-push-group",
+    "Test that push_group doesn't crash after setting a surface-based clip",
+    SIZE, SIZE,
+    draw
+};
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    /* An overly complex way of drawing a blue circle onto a red
+     * background, to trigger the bug. */
+    cairo_set_source_rgb (cr, 1, 0, 0); /* red */
+    cairo_paint (cr);
+
+    cairo_arc (cr,
+	       SIZE / 2, SIZE / 2,
+	       SIZE / 2,
+	       0, 2 * M_PI);
+    cairo_clip (cr);
+
+    cairo_push_group (cr);
+    cairo_set_source_rgb (cr, 0, 0, 1); /* blue */
+    cairo_paint (cr);
+    cairo_pop_group_to_source (cr);
+    cairo_paint (cr);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+int
+main (void)
+{
+    return cairo_test (&test);
+}