Merge pull request #37 from sethrj/master

Fix issue 35: v4 conversion failures with 'orig_nbformat_minor'

nbformat/tests/test_convert.py

@@ -7,6 +7,7 @@
 
 from ..converter import convert
 from ..reader import read, get_version
+from ..validator import isvalid, validate
 from .. import current_nbformat
 
 
@@ -38,8 +39,20 @@ def test_upgrade_2_3(self):
         self.assertEqual(major, 3)
 
 
+    def test_upgrade_downgrade_4_3_4(self):
+        """Test that a v4 notebook downgraded to v3 and then upgraded to v4
+        passes validation tests"""
+        with self.fopen(u'test4.ipynb', u'r') as f:
+            nb = read(f)
+        validate(nb)
+        nb = convert(nb, 3)
+        validate(nb)
+        nb = convert(nb, 4)
+        self.assertEqual(isvalid(nb), True)
+
+
     def test_open_current(self):
-        """Can an old notebook be opened and converted to the current version 
+        """Can an old notebook be opened and converted to the current version
         while remembering the original version of the notebook?"""
 
         # Open a version 2 notebook and attempt to upgrade it to the current version

nbformat/v4/convert.py

@@ -40,7 +40,9 @@ def upgrade(nb, from_version=3, from_minor=0):
 
         # Mark the original nbformat so consumers know it has been converted
         orig_nbformat = nb.pop('orig_nbformat', None)
+        orig_nbformat_minor = nb.pop('orig_nbformat_minor', None)
         nb.metadata.orig_nbformat = orig_nbformat or 3
+        nb.metadata.orig_nbformat_minor = orig_nbformat_minor or 0
 
         # Mark the new format
         nb.nbformat = nbformat
@@ -243,11 +245,11 @@ def downgrade(nb):
     cells = [ downgrade_cell(cell) for cell in nb.pop('cells') ]
     nb.worksheets = [v3.new_worksheet(cells=cells)]
     nb.metadata.setdefault('name', '')
-    
+
     # Validate the converted notebook before returning it
     _warn_if_invalid(nb, v3.nbformat)
-    
+
     nb.orig_nbformat = nb.metadata.pop('orig_nbformat', nbformat)
     nb.orig_nbformat_minor = nb.metadata.pop('orig_nbformat_minor', nbformat_minor)
-    
+
     return nb