Prevent errors when creating already existing tag through model entries.

contentcuration/contentcuration/db/models/manager.py

@@ -487,6 +487,7 @@ def _copy_tags(self, source_copy_id_map):
                 tag_id_map[tag.id] = new_tag.id
                 tags_to_create.append(new_tag)
 
+        # TODO: Can cleanup the above and change the below to use ignore_conflicts=True
         ContentTag.objects.bulk_create(tags_to_create)
 
         mappings_to_create = [
@@ -499,7 +500,10 @@ def _copy_tags(self, source_copy_id_map):
             for mapping in node_tags_mappings
         ]
 
-        self.model.tags.through.objects.bulk_create(mappings_to_create)
+        # In the case that we are copying a node that is in the weird state of having a tag
+        # that is duplicated (with a channel tag and a null channel tag) this can cause an error
+        # so we ignore conflicts here to ignore the duplicate tags.
+        self.model.tags.through.objects.bulk_create(mappings_to_create, ignore_conflicts=True)
 
     def _copy_assessment_items(self, source_copy_id_map):
         from contentcuration.models import File

contentcuration/contentcuration/tests/test_contentnodes.py

@@ -78,7 +78,7 @@ def _check_files_for_object(source, copy):
 
 
 def _check_tags_for_node(source, copy):
-    source_tags = source.tags.all().order_by("tag_name")
+    source_tags = source.tags.all().order_by("tag_name").distinct("tag_name")
     copy_tags = copy.tags.all().order_by("tag_name")
     assert len(source_tags) == len(copy_tags)
     for source_tag, copy_tag in zip(source_tags, copy_tags):
@@ -415,6 +415,40 @@ def test_duplicate_nodes_with_tags(self):
             num_test_tags_before, ContentTag.objects.filter(tag_name="test").count()
         )
 
+    def test_duplicate_nodes_with_duplicate_tags(self):
+        """
+        Ensures that when we copy nodes with duplicated tags they get copied
+        """
+        new_channel = testdata.channel()
+
+        tree = TreeBuilder(tags=True)
+        self.channel.main_tree = tree.root
+        self.channel.save()
+
+        # Add a legacy tag with a set channel to test the tag copying behaviour.
+        legacy_tag = ContentTag.objects.create(tag_name="test", channel=self.channel)
+        # Add an identical tag without a set channel to make sure it gets reused.
+        identical_tag = ContentTag.objects.create(tag_name="test")
+
+        num_test_tags_before = ContentTag.objects.filter(tag_name="test").count()
+
+        # Add both the legacy and the new style tag and ensure that it doesn't break.
+        self.channel.main_tree.get_children().first().tags.add(legacy_tag)
+        self.channel.main_tree.get_children().first().tags.add(identical_tag)
+
+        self.channel.main_tree.copy_to(new_channel.main_tree, batch_size=1000)
+
+        _check_node_copy(
+            self.channel.main_tree,
+            new_channel.main_tree.get_children().last(),
+            original_channel_id=self.channel.id,
+            channel=new_channel,
+        )
+
+        self.assertEqual(
+            num_test_tags_before, ContentTag.objects.filter(tag_name="test").count()
+        )
+
     def test_duplicate_nodes_deep(self):
         """
         Ensures that when we copy nodes in a deep way, a full copy happens
@@ -533,8 +567,7 @@ def test_duplicate_nodes_freeze_authoring_data_no_edit(self):
 
     def test_duplicate_nodes_no_freeze_authoring_data_edit(self):
         """
-        Ensures that when we copy nodes, we can exclude nodes from the descendant
-        hierarchy
+        Ensures that when we copy nodes, we can modify fields if they are not frozen for editing
         """
         new_channel = testdata.channel()
 
@@ -553,8 +586,7 @@ def test_duplicate_nodes_no_freeze_authoring_data_edit(self):
 
     def test_duplicate_nodes_freeze_authoring_data_edit(self):
         """
-        Ensures that when we copy nodes, we can exclude nodes from the descendant
-        hierarchy
+        Ensures that when we copy nodes, we can't modify fields if they are frozen for editing
         """
         new_channel = testdata.channel()