Update tests for WMS grouped layers order

Author: elpaso

tests/src/python/test_qgsserver_wms_getmap.py

@@ -890,12 +890,15 @@ def test_wms_getmap_sld(self):
         self._img_diff_error(r, h, "WMS_GetMap_SLDRestored")
 
     def test_wms_getmap_group(self):
+        """A WMS shall render the requested layers by drawing the leftmost in the list 
+        bottommost, the next one over that, and so on."""
+
         qs = "?" + "&".join(["%s=%s" % i for i in list({
             "MAP": urllib.parse.quote(self.projectGroupsPath),
             "SERVICE": "WMS",
             "VERSION": "1.1.1",
             "REQUEST": "GetMap",
-            "LAYERS": "Country,Country_Labels,Country_Diagrams",
+            "LAYERS": "Country_Diagrams,Country_Labels,Country",
             "STYLES": "",
             "FORMAT": "image/png",
             "BBOX": "-16817707,-4710778,5696513,14587125",
@@ -921,6 +924,16 @@ def test_wms_getmap_group(self):
         }.items())])
 
         r_group, _ = self._result(self._execute_request(qs))
+
+        """ Debug check:
+        f = open('grouped.png', 'wb+')
+        f.write(r_group)
+        f.close()
+        f = open('individual.png', 'wb+')
+        f.write(r_individual)
+        f.close()
+        #"""
+
         self.assertEqual(r_individual, r_group, 'Individual layers query and group layers query results should be identical')
 
         qs = "?" + "&".join(["%s=%s" % i for i in list({