Merge pull request #667 from kovidgoyal/fix-git-branch-name

Fix git branch name sometimes getting stuck with inotify

powerline/lib/file_watcher.py

@@ -54,7 +54,24 @@ class INotifyWatch(INotify):
 					self.modified.pop(path, None)
 					self.last_query.pop(path, None)
 				else:
-					self.modified[path] = True
+					if mask & self.ATTRIB:
+						# The watched file could have had its inode changed, in
+						# which case we will not get any more events for this
+						# file, so re-register the watch. For example by some
+						# other file being renamed as this file.
+						try:
+							self.unwatch(path)
+						except OSError:
+							pass
+						try:
+							self.watch(path)
+						except OSError as e:
+							if getattr(e, 'errno', None) != errno.ENOENT:
+								raise
+						else:
+							self.modified[path] = True
+					else:
+						self.modified[path] = True
 
 	def unwatch(self, path):
 		''' Remove the watch for path. Raises an OSError if removing the watch

powerline/lib/vcs/__init__.py

@@ -33,6 +33,15 @@ def file_watcher():
 		_file_watcher = create_file_watcher()
 	return _file_watcher
 
+_branch_watcher = None
+
+def branch_watcher():
+	global _branch_watcher
+	if _branch_watcher is None:
+		from powerline.lib.file_watcher import create_file_watcher
+		_branch_watcher = create_file_watcher()
+	return _branch_watcher
+
 branch_name_cache = {}
 branch_lock = Lock()
 file_status_lock = Lock()
@@ -41,7 +50,7 @@ def get_branch_name(directory, config_file, get_func):
 	global branch_name_cache
 	with branch_lock:
 		# Check if the repo directory was moved/deleted
-		fw = file_watcher()
+		fw = branch_watcher()
 		is_watched = fw.is_watched(directory)
 		try:
 			changed = fw(directory)

tests/test_lib.py

@@ -54,10 +54,11 @@ class TestFilesystemWatchers(TestCase):
 		w = create_file_watcher(use_stat=False)
 		if w.is_stat_based:
 			raise SkipTest('This test is not suitable for a stat based file watcher')
-		f1, f2 = os.path.join(INOTIFY_DIR, 'file1'), os.path.join(INOTIFY_DIR, 'file2')
+		f1, f2, f3 = map(lambda x: os.path.join(INOTIFY_DIR, 'file%d' % x), (1, 2, 3))
 		with open(f1, 'wb'):
 			with open(f2, 'wb'):
-				pass
+				with open(f3, 'wb'):
+					pass
 		ne = os.path.join(INOTIFY_DIR, 'notexists')
 		self.assertRaises(OSError, w, ne)
 		self.assertTrue(w(f1))
@@ -85,6 +86,13 @@ class TestFilesystemWatchers(TestCase):
 		# Check that deleting a file registers as a change
 		os.unlink(f1)
 		self.do_test_for_change(w, f1)
+		# Test that changing the inode of a file does not cause it to stop
+		# being watched
+		os.rename(f3, f2)
+		self.do_test_for_change(w, f2)
+		self.assertFalse(w(f2), 'Spurious change detected')
+		os.utime(f2, None)
+		self.do_test_for_change(w, f2)
 
 	def test_tree_watcher(self):
 		from powerline.lib.tree_watcher import TreeWatcher