testsuite: Add crossfade-clip-both-children test

This one tests a crossfade between two non-overlapping nodes with a clip
region that covers neither of the two nodes.

This tests that renderers can deal with clip regions that doesn't
overlap nodes in a situation where they will most likely want to create
an offscreen.
As offscreens are typically clipped to the clip region, this would cause
an empty offscreen and that can cause failures.

3 files changed, 19 insertions, 0 deletions

diff --git a/testsuite/gsk/compare/crossfade-clip-both-children.node b/testsuite/gsk/compare/crossfade-clip-both-children.node
new file mode 100644
index 0000000000..7af2338519
--- /dev/null
+++ b/testsuite/gsk/compare/crossfade-clip-both-children.node
@@ -0,0 +1,18 @@
+color {
+  bounds: 0 0 150 50;
+  color: rgb(0,0,0);
+}
+clip {
+  clip: 50 0 50 50;
+  child: cross-fade {
+    progress: 0.6;
+    start: color {
+      bounds: 0 0 50 50;
+      color: rgb(255,0,0);
+    }
+    end: color {
+      bounds: 100 0 50 50;
+      color: rgb(0,0,255);
+    }
+  }
+}
diff --git a/testsuite/gsk/compare/crossfade-clip-both-children.png b/testsuite/gsk/compare/crossfade-clip-both-children.png
new file mode 100644
index 0000000000..ea47119187
--- /dev/null
+++ b/testsuite/gsk/compare/crossfade-clip-both-children.png
diff --git a/testsuite/gsk/meson.build b/testsuite/gsk/meson.build
index 999e955ce5..263d13cf29 100644
--- a/testsuite/gsk/meson.build
+++ b/testsuite/gsk/meson.build
@@ -35,6 +35,7 @@ compare_render_tests = [
   'color-blur0',
   'color-matrix-identity',
   'color-matrix-parsing',
+  'crossfade-clip-both-children',
   'cross-fade-in-opacity',
   'cross-fade-in-rotate',
   'css-background',