Fix get_ratio for empty strings

1 files changed, 5 insertions, 1 deletions

diff --git a/tests/test_versioning.py b/tests/test_versioning.py
index 06c4ff2f1..923da2035 100644
--- a/tests/test_versioning.py
+++ b/tests/test_versioning.py
@@ -16,7 +16,7 @@ from docutils.statemachine import ViewList
 from docutils.parsers.rst.directives.html import MetaBody
 
 from sphinx import addnodes
-from sphinx.versioning import add_uids, merge_doctrees
+from sphinx.versioning import add_uids, merge_doctrees, get_ratio
 
 def setup_module():
     global app, original, original_uids
@@ -39,6 +39,10 @@ def on_doctree_resolved(app, doctree, docname):
 def is_paragraph(node):
     return node.__class__.__name__ == 'paragraph'
 
+def test_get_ratio():
+    assert get_ratio('', 'a')
+    assert get_ratio('a', '')
+
 def test_add_uids():
     assert len(original_uids) == 3