deposit: really remove old user email when present

* It is not enough to remove the `current_user_mail` legacy field from
  the merge comparison, but it must be removed also by the dump when
  merging the deposit and the record.
* Given that the `current_user_mail` field might still be present in
  some records, it should be ignored/removed when loading the record via
  marshmallow.

cds/modules/invenio_deposit/api.py

@@ -188,14 +188,16 @@ def merge_with_published(self):
         args = [lca.dumps(), first.dumps(), self.dumps()]
         for arg in args:
             del arg["$schema"], arg["_deposit"]
-            # pop optional removed key `current_user_mail` when present
+            # skip legacy `current_user_mail` when comparing for merging
             arg.get("_cds", {}).pop("current_user_mail", None)
         args.append({})
         m = Merger(*args)
         try:
             m.run()
         except UnresolvedConflictsException:
             raise MergeConflict()
+        # remove legacy `current_user_mail` when merging
+        lca.get("_cds", {}).pop("current_user_mail", None)
         return patch(m.unified_patches, lca)
 
     @index

cds/modules/records/serializers/schemas/project.py

@@ -19,7 +19,7 @@
 """Project JSON schema."""
 
 from invenio_jsonschemas import current_jsonschemas
-from marshmallow import Schema, fields, post_load
+from marshmallow import Schema, fields, pre_load, post_load
 
 from ....deposit.api import Project, deposit_video_resolver
 from .common import (
@@ -44,6 +44,12 @@ class _CDSSSchema(Schema):
     state = fields.Raw()
     modified_by = fields.Int()
 
+    @pre_load
+    def remove_legacy_fields(self, data, **kwargs):
+        """Remove legacy fields."""
+        data.pop("current_user_mail", None)
+        return data
+
 
 class ProjectDepositSchema(DepositSchema):
     """Project Deposit Schema."""

cds/modules/records/serializers/schemas/video.py

@@ -19,7 +19,7 @@
 """Video JSON schema."""
 
 from invenio_jsonschemas import current_jsonschemas
-from marshmallow import Schema, fields, post_load
+from marshmallow import Schema, fields, pre_load, post_load
 
 from ....deposit.api import Video
 from ..fields.datetime import DateString
@@ -47,6 +47,12 @@ class _CDSSSchema(Schema):
     extracted_metadata = fields.Raw()
     modified_by = fields.Int()
 
+    @pre_load
+    def remove_legacy_fields(self, data, **kwargs):
+        """Remove legacy fields."""
+        data.pop("current_user_mail", None)
+        return data
+
 
 class VideoDepositSchema(DepositSchema):
     """Project Deposit Schema."""