@@ -23,11 +23,11 @@
 def start(): # Gets invoked at the bottom of this file.
     """
     Regularly (every 5s) updates the file_exclude_patterns setting.
-    """    
+    """
     if is_first_launch():
         migrate_exclude_patterns()
         record_first_launch()
-    
+
     def run():
         update_file_exclude_patterns()
         sublime.set_timeout(run, 5000)
@@ -38,13 +38,13 @@ def update_file_exclude_patterns():
     """
     Updates the "file_exclude_patterns" preference to include all .gitignored
     files.
-    
+
     Also includes any additional files or folders listed in the
     "extra_file_exclude_patterns" and "extra_folder_exclude_patterns" settings.
     """
     s = sublime.load_settings("Preferences.sublime-settings")
-    file_exclude_patterns = s.get('extra_file_exclude_patterns', [])
-    folder_exclude_patterns = s.get('extra_folder_exclude_patterns', [])
+    file_exclude_patterns = s.get('extra_file_exclude_patterns', []) or []
+    folder_exclude_patterns = s.get('extra_folder_exclude_patterns', []) or []
     for path in all_ignored_paths():
         is_directory = os.path.isdir(path)
         if platform.system() == 'Windows':
@@ -63,13 +63,13 @@ def update_file_exclude_patterns():
             file_exclude_patterns.append(path)
 
     new_files = set(file_exclude_patterns)
-    old_files = set(s.get('file_exclude_patterns', []))
+    old_files = set(s.get('file_exclude_patterns', []) or [])
     new_folders = set(folder_exclude_patterns)
-    old_folders = set(s.get('folder_exclude_patterns', []))
-    
+    old_folders = set(s.get('folder_exclude_patterns', []) or [])
+
     # Only make changes if anything has actually changed, to avoid spamming the
     # sublime console
-    if new_files != old_files or new_folders != old_folders:        
+    if new_files != old_files or new_folders != old_folders:
         s.set('file_exclude_patterns', list(file_exclude_patterns))
         s.set('folder_exclude_patterns', list(folder_exclude_patterns))
         sublime.save_settings("Preferences.sublime-settings")
@@ -79,32 +79,32 @@ def all_ignored_paths():
     Returns a list of all .gitignored files or folders contained in repos
     contained within or containing any folders open in any open windows.
     """
-    
+
     open_folders = set()
     for window in sublime.windows():
         open_folders.update(window.folders())
-    
+
     all_ignored_paths = set()
     for folder in open_folders:
         ignored_paths = folder_ignored_paths(folder)
         all_ignored_paths.update(ignored_paths)
-        
+
     return list(all_ignored_paths)
 
 def folder_ignored_paths(folder):
     """
     Returns a list (without duplicates, in the case of weird repo-nesting) of
     all files/folders within the given folder that are git ignored.
-    
-    The folder itself need not be the top level of a git repo, nor even within 
+
+    The folder itself need not be the top level of a git repo, nor even within
     a git repo.
     """
-    
+
     all_ignored_paths = set()
-    
+
     # First find all repos CONTAINED in this folder:
     repos = set(find_git_repos(folder))
-    
+
     # Then, additionally, if this folder is itself contained within a repo,
     # find the .git folder of the repo containing it:
     if is_in_git_repo(folder):
@@ -114,30 +114,30 @@ def folder_ignored_paths(folder):
     for git_repo in repos:
         ignored_paths = repo_ignored_paths(git_repo)
         all_ignored_paths.update(ignored_paths)
-            
+
     return list(all_ignored_paths)
 
 def is_in_git_repo(folder):
     """
     Returns true if the given folder is contained within a git repo
     """
-    
+
     exit_code = subprocess.call(
         ["git", "rev-parse", "--is-inside-work-tree"],
         cwd=folder,
         stdout=devnull,
         stderr=devnull,
         startupinfo=startupinfo
     )
-    
+
     return exit_code == 0
 
 def parent_repo_path(folder):
     """
     Takes the path to a folder contained within a git repo, and returns the
     parent repo.
     """
-    
+
     # abspath call converts forward slashes to backslashes on Windows; we do
     # this wherever necessary to keep the format of our paths standardised on
     # Windows.
@@ -154,7 +154,7 @@ def find_git_repos(folder):
     """
     Returns a list of all git repos within the given ancestor folder.
     """
-    
+
     return [root for root, subfolders, files
                  in os.walk(folder)
                  if '.git' in subfolders]
@@ -164,7 +164,7 @@ def repo_ignored_paths(git_repo):
     Takes the path of a git repo and lists all ignored files/folders in the
     repo.
     """
-        
+
     # Trick for listing ignored files nicked from
     # http://stackoverflow.com/a/2196755/1709587
     command_output = subprocess.Popen(
@@ -174,38 +174,37 @@ def repo_ignored_paths(git_repo):
         startupinfo=startupinfo,
         env={'LANG':'C'}
     ).stdout.read()
-    
+
     command_output = command_output.decode('utf-8', 'ignore')
-    
+
     if command_output.isspace() or command_output == u'':
-        return []   
-       
+        return []
+
     lines = command_output.strip().split(u'\n')
     # Each line in `lines` now looks something like:
     # "Would remove foo/bar/yourfile.txt"
-    
+
     relative_paths = [line.replace(u'Would remove ', u'', 1).rstrip(u'/')
                       for line in lines]
     absolute_paths = [os.path.join(git_repo, path) for path in relative_paths]
-    
     return absolute_paths
-    
+
 def is_first_launch():
     s = sublime.load_settings("gitignorer.sublime-settings")
     return not s.get('_sublime_gitignorer_has_run', False)
-    
+
 def migrate_exclude_patterns():
     """
     Runs on first launch; purpose is to prevent people who have already set
     exclusion patterns from losing them when they install this package.
     """
     s = sublime.load_settings("Preferences.sublime-settings")
-    existing_file_exclude_patterns = s.get('file_exclude_patterns', [])
-    existing_folder_exclude_patterns = s.get('folder_exclude_patterns', [])
+    existing_file_exclude_patterns = s.get('file_exclude_patterns', []) or []
+    existing_folder_exclude_patterns = s.get('folder_exclude_patterns', []) or []
     s.set('extra_file_exclude_patterns', existing_file_exclude_patterns)
     s.set('extra_folder_exclude_patterns', existing_folder_exclude_patterns)
     sublime.save_settings("Preferences.sublime-settings")
-    
+
 def record_first_launch():
     s = sublime.load_settings("gitignorer.sublime-settings")
     s.set('_sublime_gitignorer_has_run', True)
@@ -225,5 +224,5 @@ def windows_path_to_sublime_path(path):
     assert(path[1] == u':')
     without_colon = path[0] + path[2:]
     return without_colon.replace(u'\\', u'/')
-    
+
 start()