Move datasets to delete first in line

We have reports of datasets that get re-harvested with an extra `1` in the URL. We have confirmed these reports.
It seems the harvest is doing the best it can to diagnose if this is a new dataset or not; but still failing in some circumstances.
This probably won't fix the bug; however it will mitigate it. By hopefully running through the datasets removal first, if the spatial harvester is essentially doing a "delete and add" when it should be replacing, then the name of the new dataset won't collide with the one that is marked for deleted but still in the system.

ckanext/spatial/harvesters/waf.py

@@ -138,6 +138,19 @@ def create_extras(url, date, status):
 
 
         ids = []
+        for location in delete:
+            obj = HarvestObject(job=harvest_job,
+                                extras=create_extras('','', 'delete'),
+                                guid=url_to_ids[location][0],
+                                package_id=url_to_ids[location][1],
+                               )
+            model.Session.query(HarvestObject).\
+                  filter_by(guid=url_to_ids[location][0]).\
+                  update({'current': False}, False)
+
+            obj.save()
+            ids.append(obj.id)
+
         for location in new:
             guid=hashlib.md5(location.encode('utf8','ignore')).hexdigest()
             obj = HarvestObject(job=harvest_job,
@@ -160,19 +173,6 @@ def create_extras(url, date, status):
             obj.save()
             ids.append(obj.id)
 
-        for location in delete:
-            obj = HarvestObject(job=harvest_job,
-                                extras=create_extras('','', 'delete'),
-                                guid=url_to_ids[location][0],
-                                package_id=url_to_ids[location][1],
-                               )
-            model.Session.query(HarvestObject).\
-                  filter_by(guid=url_to_ids[location][0]).\
-                  update({'current': False}, False)
-
-            obj.save()
-            ids.append(obj.id)
-
         if len(ids) > 0:
             log.debug('{0} objects sent to the next stage: {1} new, {2} change, {3} delete'.format(
                 len(ids), len(new), len(change), len(delete)))