[gtk] testsuite: Add blur node testcase

[Timm Bäder <baedert src gnome org>]

commit 730b52b0844154f57714fe1f02bc64966a16e492
Author: Timm Bäder <mail baedert org>
Date:   Tue May 7 17:19:00 2019 +0200

    testsuite: Add blur node testcase
    
    Renderers need to handle blur radius 0 as well. Currently broken in GL
    and (I guess, unless it's my driver) Vulkan.

 testsuite/gsk/compare/color-blur0.node |   7 +++++++
 testsuite/gsk/compare/color-blur0.png  | Bin 0 -> 305 bytes
 testsuite/gsk/meson.build              |   1 +
 3 files changed, 8 insertions(+)
---
diff --git a/testsuite/gsk/compare/color-blur0.node b/testsuite/gsk/compare/color-blur0.node
new file mode 100644
index 0000000000..46e7bcbde0
--- /dev/null
+++ b/testsuite/gsk/compare/color-blur0.node
@@ -0,0 +1,7 @@
+blur {
+  blur: 0;
+  child :color {
+    color: red;
+    bounds: 0 0 100 100;
+  }
+}
\ No newline at end of file
diff --git a/testsuite/gsk/compare/color-blur0.png b/testsuite/gsk/compare/color-blur0.png
new file mode 100644
index 0000000000..3c3464bed8
Binary files /dev/null and b/testsuite/gsk/compare/color-blur0.png differ
diff --git a/testsuite/gsk/meson.build b/testsuite/gsk/meson.build
index 90eed14aa9..5ed0d2fe1e 100644
--- a/testsuite/gsk/meson.build
+++ b/testsuite/gsk/meson.build
@@ -38,6 +38,7 @@ compare_render_tests = [
   'shadow-in-opacity',
   'blend-normal',
   'blend-difference',
+  'color-blur0',
 ]
 
 renderers = [