Change the way new document version are blocked, moving the logic to the documents app from the checkouts app signal handler. Disable the upload new document version button and have the new version upload view redirect to the document version list with a message. GitLab issue #231.

mayan/apps/documents/models.py

@@ -31,10 +31,11 @@ from .events import (
     event_document_properties_edit, event_document_type_change,
     event_document_version_revert
 )
+from .exceptions import NewDocumentVersionNotAllowed
 from .literals import DEFAULT_DELETE_PERIOD, DEFAULT_DELETE_TIME_UNIT
 from .managers import (
-    DocumentManager, DocumentTypeManager, PassthroughManager,
-    RecentDocumentManager, TrashCanManager
+    DocumentManager, DocumentTypeManager, NewVersionBlockManager,
+    PassthroughManager, RecentDocumentManager, TrashCanManager
 )
 from .permissions import permission_document_view
 from .runtime import cache_storage_backend, storage_backend
@@ -397,6 +398,8 @@ class DocumentVersion(models.Model):
 
         if new_document_version:
             logger.info('Creating new version for document: %s', self.document)
+            if NewVersionBlock.objects.is_blocked(self.document):
+                raise NewDocumentVersionNotAllowed
 
         try:
             with transaction.atomic():
@@ -779,6 +782,17 @@ class DocumentPage(models.Model):
         return '{}-{}'.format(self.document_version.uuid, self.pk)
 
 
+
+class NewVersionBlock(models.Model):
+    document = models.ForeignKey(Document, verbose_name=_('Document'))
+
+    objects = NewVersionBlockManager()
+
+    class Meta:
+        verbose_name = _('New version block')
+        verbose_name_plural = _('New version blocks')
+
+
 @python_2_unicode_compatible
 class RecentDocument(models.Model):
     """