When recording a tag, the key and value must be at least one character long.

test/TodoBaseTest.py

@@ -105,6 +105,20 @@ class TodoBaseTester(unittest.TestCase):
         self.assertFalse(todo.has_tag('foo'))
         self.assertFalse(re.search(r'\bfoo:', todo.src))
 
+    def test_tag_empty_value(self):
+        """ Tag should not be recorded when there is no value. """
+
+        todo = TodoBase("(C) Foo foo:")
+
+        self.assertFalse(todo.has_tag('foo'))
+
+    def test_tag_empty_key(self):
+        """ Tag should not be recorded when there is no key. """
+
+        todo = TodoBase("(C) Foo :bar")
+
+        self.assertFalse(todo.has_tag(''))
+
     def test_remove_all(self):
         todo = TodoBase("(C) Foo foo:bar foo:baz foo:")
         todo.remove_tag('foo')

topydo/lib/TodoParser.py

@@ -33,7 +33,7 @@ _NORMAL_HEAD_MATCH = re.compile(
     r'(\((?P<priority>[A-Z])\) )?' + '((?P<creationDate>' + _DATE_MATCH +
     ') )?(?P<rest>.*)')
 
-_TAG_MATCH = re.compile('(?P<key>[^:]*):(?P<value>.*)')
+_TAG_MATCH = re.compile('(?P<key>[^:]+):(?P<value>.+)')
 _PROJECT_MATCH = re.compile(r'\+(\S*\w)')
 _CONTEXT_MATCH = re.compile(r'@(\S*\w)')