Automatic orientation issues detection and fix, experimental

tests/test_crop_margins_command.py

@@ -79,6 +79,15 @@ class CropMarginsCommandTests(unittest.TestCase):
         self.assertAlmostEqual(average, (28.3465 + 56.6929) / 2, places=3)
         self.assertEqual(over_thirty, 1)
 
+    def test_cropping_keeps_original_page_identity_valid(self):
+        from copienator.orientation import save_provenance, load_provenance
+        with pymupdf.open(self.source) as document:
+            origins = [{'origin': i + 1} for i in range(len(document))]
+        save_provenance(self.workspace, self.source, origins)
+        with contextlib.redirect_stdout(io.StringIO()):
+            crop_margins.run(self.workspace, self.workspace.root, workers=1)
+        self.assertEqual(load_provenance(self.workspace, self.source, len(origins)), origins)
+
     def test_failure_or_interruption_never_publishes_partial_batch(self):
         second = self.workspace.copies_dir/"Copie02.pdf"
         second.write_bytes(self.original)