Fix layer exclusion for priority value of 0

This fixes the preview layer priority when editing the
redactions of pages that also contain transformations in
other layers.

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

HISTORY.rst

@@ -2,6 +2,9 @@
 ===================
 - Fix a regression in the document version page image cache maximum size
   setting callback.
+- Fix converter layer priority exclusion for layers with a priority of 0.
+  This fixes the preview layer priority when editing the redactions of pages
+  that also contain transformations in other layers.
 
 4.0.13 (2021-08-02)
 ===================

mayan/apps/converter/classes.py

@@ -351,7 +351,7 @@ def add_transformation_to(
 
         if self in transformation_class._layer_transformations:
             return object_layer.transformations.create(
-                arguments=arguments, order=order,
+                arguments=arguments or '', order=order,
                 name=transformation_class.name
             )
         else:

mayan/apps/converter/managers.py

@@ -35,16 +35,16 @@ def get_for_object(
             object_layer__object_id=obj.pk, object_layer__enabled=True
         )
 
-        access_layers = StoredLayer.objects.all()
-        exclude_layers = StoredLayer.objects.none()
-
-        if maximum_layer_order:
+        if maximum_layer_order is not None:
             access_layers = StoredLayer.objects.filter(
                 order__lte=maximum_layer_order
             )
             exclude_layers = StoredLayer.objects.filter(
                 order__gt=maximum_layer_order
             )
+        else:
+            access_layers = StoredLayer.objects.all()
+            exclude_layers = StoredLayer.objects.none()
 
         for stored_layer in access_layers:
             try:

mayan/apps/redactions/tests/literals.py

@@ -1,2 +1,12 @@
+import os
+
+from django.conf import settings
+
 TEST_REDACTION_ARGUMENT = "{'left': 10, 'top': 10, 'right': 10, 'bottom': 10}"
 TEST_REDACTION_ARGUMENT_EDITED = "{'left': 20, 'top': 20, 'right': 20, 'bottom': 20}"
+
+TEST_REDACTION_DOCUMENT_FILENAME = 'black_upper_left_corner.png'
+TEST_REDACTION_DOCUMENT_PATH = os.path.join(
+    settings.BASE_DIR, 'apps', 'redactions', 'tests', 'contrib',
+    'sample_documents', TEST_REDACTION_DOCUMENT_FILENAME
+)

mayan/apps/redactions/tests/mixins.py

@@ -0,0 +1,12 @@
+from ..layers import layer_redactions
+
+
+class LayerMaximumOrderAPIViewTestMixin:
+    def _request_document_file_page_image_api_view_with_maximum_layer_order(self):
+        return self.get(
+            viewname='rest_api:documentfilepage-image', kwargs={
+                'document_id': self.test_document.pk,
+                'document_file_id': self.test_document_file.pk,
+                'document_file_page_id': self.test_document_file_page.pk,
+            }, query={'maximum_layer_order': layer_redactions.order}
+        )

mayan/apps/redactions/tests/test_api.py

@@ -0,0 +1,44 @@
+from io import BytesIO
+
+from PIL import Image
+
+from rest_framework import status
+
+from mayan.apps.rest_api.tests.base import BaseAPITestCase
+
+from mayan.apps.converter.layers import layer_saved_transformations
+from mayan.apps.converter.transformations import TransformationRotate270
+from mayan.apps.documents.permissions import permission_document_file_view
+from mayan.apps.documents.tests.mixins.document_mixins import DocumentTestMixin
+
+from .literals import TEST_REDACTION_DOCUMENT_PATH
+from .mixins import LayerMaximumOrderAPIViewTestMixin
+
+
+class LayerMaximumOrderAPIViewTestCase(
+    LayerMaximumOrderAPIViewTestMixin, DocumentTestMixin, BaseAPITestCase
+):
+    test_document_path = TEST_REDACTION_DOCUMENT_PATH
+
+    def test_redaction_maximum_layer_order(self):
+        self.grant_access(
+            obj=self.test_document, permission=permission_document_file_view
+        )
+
+        layer_saved_transformations.add_transformation_to(
+            obj=self.test_document_file_page,
+            transformation_class=TransformationRotate270
+        )
+
+        self._clear_events()
+
+        response = self._request_document_file_page_image_api_view_with_maximum_layer_order()
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
+        image_buffer = BytesIO(response.content)
+        image = Image.open(fp=image_buffer)
+
+        self.assertEqual(image.getpixel(xy=(0, 0)), (0, 0, 0))
+
+        events = self._get_test_events()
+        self.assertEqual(events.count(), 0)

mayan/apps/redactions/tests/test_views.py

@@ -12,7 +12,7 @@
 )
 
 
-class RedactionViewsTestCase(
+class RedactionViewTestCase(
     TransformationTestMixin, TransformationViewsTestMixin,
     GenericDocumentViewTestCase
 ):