bugfix and tests for no settings path (no -s option)

pelican/tests/test_utils.py

@@ -150,6 +150,10 @@ class TestUtils(LoggedTestCase):
         self.assertEqual(next(folder_watcher), True)
         self.assertEqual(next(file_watcher), True)
 
+        # file watcher with None or empty path should return None
+        self.assertEqual(next(utils.file_watcher('')), None)
+        self.assertEqual(next(utils.file_watcher(None)), None)
+
         empty_path = os.path.join(os.path.dirname(__file__), 'empty')
         try:
             os.mkdir(empty_path)

pelican/utils.py

@@ -463,12 +463,15 @@ def file_watcher(path):
     '''Generator for monitoring a file for modifications'''
     LAST_MTIME = 0
     while True:
-        mtime = os.stat(path).st_mtime
-        if mtime > LAST_MTIME:
-            LAST_MTIME = mtime
-            yield True
+        if path:
+            mtime = os.stat(path).st_mtime
+            if mtime > LAST_MTIME:
+                LAST_MTIME = mtime
+                yield True
+            else:
+                yield False
         else:
-            yield False
+            yield None
 
 
 def set_date_tzinfo(d, tz_name=None):