test: Add inifinite-loop test

This test demonstrates a bug where a certain transformation matrix can
result in an infinite loop. It was extracted as a standalone version
of "affine-test 212944861".

If given the option -nf, the test program will not call fail_after()
and therefore potentially run forever.

2 files changed, 40 insertions, 0 deletions

diff --git a/test/Makefile.sources b/test/Makefile.sources
index 3e37e32..0f34411 100644
--- a/test/Makefile.sources
+++ b/test/Makefile.sources
@@ -7,6 +7,7 @@ TESTPROGRAMS =			\
 	fetch-test		\
 	rotate-test		\
 	oob-test		\
+	infinite-loop		\
 	trap-crasher		\
 	alpha-loop		\
 	scaling-crash-test	\
diff --git a/test/infinite-loop.c b/test/infinite-loop.c
new file mode 100644
index 0000000..02addaa
--- /dev/null
+++ b/test/infinite-loop.c
@@ -0,0 +1,39 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "utils.h"
+
+int
+main (int argc, char **argv)
+{
+#define SRC_WIDTH 16
+#define SRC_HEIGHT 12
+#define DST_WIDTH 7
+#define DST_HEIGHT 2
+
+    static const pixman_transform_t transform = {
+	{ { 0x200017bd, 0x00000000, 0x000e6465 },
+	  { 0x00000000, 0x000a42fd, 0x000e6465 },
+	  { 0x00000000, 0x00000000, 0x00010000 },
+	}
+    };
+    pixman_image_t *src, *dest;
+
+    src = pixman_image_create_bits (
+	PIXMAN_a8r8g8b8, SRC_WIDTH, SRC_HEIGHT, NULL, -1);
+    dest = pixman_image_create_bits (
+	PIXMAN_a8r8g8b8, DST_WIDTH, DST_HEIGHT, NULL, -1);
+
+    pixman_image_set_transform (src, &transform);
+    pixman_image_set_repeat (src, PIXMAN_REPEAT_NORMAL);
+    pixman_image_set_filter (src, PIXMAN_FILTER_BILINEAR, NULL, 0);
+
+    if (argc == 1 || strcmp (argv[1], "-nf") != 0)
+	fail_after (1, "infinite loop detected");
+
+    pixman_image_composite (
+	PIXMAN_OP_OVER, src, NULL, dest, -3, -3, 0, 0, 0, 0, 6, 2);
+
+    return 0;
+}