Guard for missing dates.

Todo.py

@@ -20,7 +20,7 @@ class Todo(TodoBase.TodoBase):
     def get_date(self, p_tag):
         """ Given a date tag, return a date object. """
         string = self.tag_value(p_tag)
-        return Utils.date_string_to_date(string)
+        return Utils.date_string_to_date(string) if string else None
 
     def start_date(self):
         """ Returns a date object of the todo's start date. """

Utils.py

@@ -12,18 +12,18 @@ def date_string_to_date(p_date):
     """
     result = None
 
-    parsed_date = re.match(r'(\d{4})-(\d{2})-(\d{2})', p_date)
+    if p_date:
+        parsed_date = re.match(r'(\d{4})-(\d{2})-(\d{2})', p_date)
+        if parsed_date:
+            try:
+                date = datetime.date(
+                    int(parsed_date.group(1)), # year
+                    int(parsed_date.group(2)), # month
+                    int(parsed_date.group(3))  # day
+                )
 
-    if parsed_date:
-        try:
-            date = datetime.date(
-                int(parsed_date.group(1)), # year
-                int(parsed_date.group(2)), # month
-                int(parsed_date.group(3))  # day
-            )
-
-            result = date
-        except ValueError:
-            pass # just return None
+                result = date
+            except ValueError:
+                pass # just return None
 
     return result