Issue #1: Fixes parsing of lines that shouldn't exist in default diffs

Author: cscorley

tests/test_patch.py

@@ -794,16 +794,9 @@ def test_diff_default_blah(self):
                 changes=[
                     (1, None, 'The Way that can be told of is not the eternal Way;'),
                     (2, None, 'The name that can be named is not the eternal name.'),
-                    (3, 1, 'The Nameless is the origin of Heaven and Earth;'),
                     (4, None, 'The Named is the mother of all things.'),
                     (None, 2, 'The named is the mother of all things.'),
                     (None, 3, ''),
-                    (5, 4, 'Therefore let there always be non-being,'),
-                    (6, 5, '  so we may see their subtlety,'),
-                    (7, 6, 'And let there always be being,'),
-                    (9, 8, 'The two are the same,'),
-                    (10, 9, 'But after they are produced,'),
-                    (11, 10, '  they have different names.'),
                     (None, 11, 'They both may be called deep and profound.'),
                     (None, 12, 'Deeper and more profound,'),
                     (None, 13, 'The door of all subtleties!')],

whatthepatch/patch.py

@@ -512,10 +512,10 @@ def parse_default_diff(text):
                     kind = c.group(1)
                     line = c.group(2)
 
-                    if kind == '<':# and r != old_len:
+                    if kind == '<' and (r != old_len or r == 0):
                         changes.append((old + r, None, line))
                         r += 1
-                    elif kind == '>':# and i != new_len:
+                    elif kind == '>' and (i != new_len or i == 0):
                         changes.append((None, new + i, line))
                         i += 1