[gegl/wip/rishi/issue-60: 1192/1192] tools/gegl-imgcmp: fail if no output image

[Michael Schumacher <schumaml src gnome org>]

commit 9c8f0bfc33e5a82009c41b82c8b91f8d84fd9333
Author: Shlomi Fish <shlomif shlomifish org>
Date:   Mon May 28 19:35:29 2018 +0200

    tools/gegl-imgcmp: fail if no output image
    
    https://gitlab.gnome.org/GNOME/gegl/issues/60

 tools/gegl-imgcmp.c | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/tools/gegl-imgcmp.c b/tools/gegl-imgcmp.c
index 1a5289210..87cba042f 100644
--- a/tools/gegl-imgcmp.c
+++ b/tools/gegl-imgcmp.c
@@ -95,6 +95,11 @@ main (gint    argc,
     g_print ("raster md5s differ: %s vs %s\n", md5A, md5B);
   }
 
+  if( access( argv[2], F_OK ) != 0 ) {
+    g_print ("missing output image, failing\n");
+    return ERROR_PIXELS_DIFFERENT;
+  }
+
   gegl = gegl_node_new ();
   imgA = gegl_node_new_child (gegl,
                               "operation", "gegl:load",