m2c uses matches_po_current_version? to compare po/pc versions

  Fixes #483

app/services/preserved_object_handler.rb

@@ -69,7 +69,7 @@ def check_existence
           # FIXME: what if there is more than one associated pres_copy?
           pres_copy = PreservedCopy.find_by!(preserved_object: pres_object, endpoint: endpoint) if pres_object
 
-          raise_rollback_if_pc_po_version_mismatch(pres_copy.version, pres_object.current_version)
+          raise_rollback_if_pc_po_version_mismatch(pres_copy)
 
           if incoming_version == pres_copy.version
             set_status_as_seen_on_disk(pres_copy, true) unless pres_copy.status == PreservedCopy::OK_STATUS
@@ -218,7 +218,7 @@ def update_online_version(status=nil, set_status_to_unexp_version=false)
       pres_object = PreservedObject.find_by!(druid: druid)
       pres_copy = PreservedCopy.find_by!(preserved_object: pres_object, endpoint: endpoint) if pres_object
 
-      raise_rollback_if_pc_po_version_mismatch(pres_copy.version, pres_object.current_version)
+      raise_rollback_if_pc_po_version_mismatch(pres_copy)
 
       # FIXME: what if there is more than one associated pres_copy?
       if incoming_version > pres_copy.version && pres_copy.version == pres_object.current_version
@@ -243,8 +243,10 @@ def update_online_version(status=nil, set_status_to_unexp_version=false)
     handler_results.remove_db_updated_results unless transaction_ok
   end
 
-  def raise_rollback_if_pc_po_version_mismatch(pc_version, po_version)
-    if pc_version != po_version
+  def raise_rollback_if_pc_po_version_mismatch(pres_copy)
+    unless pres_copy.matches_po_current_version?
+      pc_version = pres_copy.version
+      po_version = pres_copy.preserved_object.current_version
       res_code = PreservedObjectHandlerResults::PC_PO_VERSION_MISMATCH
       handler_results.add_result(res_code, { pc_version: pc_version, po_version: po_version })
       raise ActiveRecord::Rollback, "PreservedCopy version #{pc_version} != PreservedObject current_version #{po_version}"
@@ -303,7 +305,7 @@ def confirm_online_version
       # FIXME: what if there is more than one associated pres_copy?
       pres_copy = PreservedCopy.find_by!(preserved_object: pres_object, endpoint: endpoint) if pres_object
 
-      raise_rollback_if_pc_po_version_mismatch(pres_copy.version, pres_object.current_version)
+      raise_rollback_if_pc_po_version_mismatch(pres_copy)
 
       if incoming_version == pres_copy.version
         set_status_as_seen_on_disk(pres_copy, true) unless pres_copy.status == PreservedCopy::OK_STATUS

spec/services/preserved_object_handler_check_exist_spec.rb

@@ -461,10 +461,11 @@
         po_handler = described_class.new(druid, 1, 1, ep)
         po = instance_double(PreservedObject)
         pc = instance_double(PreservedCopy)
-        allow(PreservedObject).to receive(:find_by).with(druid: druid).and_return(po)
+        allow(PreservedObject).to receive(:find_by!).with(druid: druid).and_return(po)
         allow(po).to receive(:current_version).and_return(1)
         allow(po).to receive(:touch)
-        allow(PreservedCopy).to receive(:find_by).with(preserved_object: po, endpoint: ep).and_return(pc)
+        allow(PreservedCopy).to receive(:find_by!).with(preserved_object: po, endpoint: ep).and_return(pc)
+        allow(pc).to receive(:matches_po_current_version?).and_return(true)
         allow(pc).to receive(:status).and_return(PreservedCopy::OK_STATUS)
         allow(pc).to receive(:version).and_return(1)
         allow(pc).to receive(:update_audit_timestamps)

spec/services/preserved_object_handler_confirm_version_spec.rb

@@ -264,6 +264,7 @@
             allow(pc).to receive(:update_audit_timestamps)
             allow(pc).to receive(:changed?).and_return(true)
             allow(pc).to receive(:save!).and_raise(ActiveRecord::ActiveRecordError, 'foo')
+            allow(pc).to receive(:matches_po_current_version?).and_return(true)
             allow(po).to receive(:current_version).and_return(2)
             allow(po_handler).to receive(:moab_validation_errors).and_return([])
             po_handler.confirm_version
@@ -288,6 +289,7 @@
         allow(pc).to receive(:update_audit_timestamps)
         allow(pc).to receive(:changed?).and_return(true)
         allow(pc).to receive(:save!)
+        allow(pc).to receive(:matches_po_current_version?).and_return(true)
         allow(po_handler).to receive(:moab_validation_errors).and_return([])
         po_handler.confirm_version
         expect(po).not_to have_received(:save!)
@@ -306,6 +308,7 @@
         allow(pc).to receive(:update_audit_timestamps)
         allow(pc).to receive(:changed?).and_return(false)
         allow(pc).to receive(:touch)
+        allow(pc).to receive(:matches_po_current_version?).and_return(true)
         po_handler.confirm_version
         expect(po).not_to have_received(:touch)
         expect(pc).to have_received(:touch)

spec/services/preserved_object_handler_update_version_spec.rb

@@ -160,6 +160,7 @@
               allow(pc).to receive(:update_audit_timestamps)
               allow(pc).to receive(:changed?).and_return(true)
               allow(pc).to receive(:save!).and_raise(ActiveRecord::ActiveRecordError, 'foo')
+              allow(pc).to receive(:matches_po_current_version?).and_return(true)
               po_handler.update_version
             end
 
@@ -202,6 +203,7 @@
               allow(pc).to receive(:update_audit_timestamps)
               allow(pc).to receive(:changed?).and_return(true)
               allow(pc).to receive(:save!)
+              allow(pc).to receive(:matches_po_current_version?).and_return(true)
               po_handler.update_version
             end
 
@@ -241,6 +243,7 @@
         allow(pc).to receive(:update_audit_timestamps)
         allow(pc).to receive(:changed?).and_return(true)
         allow(pc).to receive(:save!)
+        allow(pc).to receive(:matches_po_current_version?).and_return(true)
         po_handler.update_version
         expect(po).to have_received(:save!)
         expect(pc).to have_received(:save!)
@@ -259,6 +262,7 @@
         allow(pc).to receive(:update_status)
         allow(pc).to receive(:changed?).and_return(true)
         allow(pc).to receive(:save!)
+        allow(pc).to receive(:matches_po_current_version?).and_return(true)
         po_handler = described_class.new(druid, 1, 1, ep)
         po_handler.update_version
         expect(po).not_to have_received(:touch)