From d464ff84bbc0f9510ae9dad9014133e3e3e05007 Mon Sep 17 00:00:00 2001
From: Foo <kp-pav@yandex.ru>
Date: Fri, 17 Apr 2015 22:01:10 +0300
Subject: [PATCH] Fix warning when &l:statusline is set to a unicode value

This normally should not happen because &l:stl should be powerline-controlled,
but some plugins do this.

Fixes #1347
---
 powerline/vim.py                    | 34 ++++++++++++++++++++++++-----
 tests/test_foreign_stl_override.vim | 22 +++++++++++++++++++
 2 files changed, 51 insertions(+), 5 deletions(-)
 create mode 100644 tests/test_foreign_stl_override.vim

diff --git a/powerline/vim.py b/powerline/vim.py
index d4f5c2d6..53e23147 100644
--- a/powerline/vim.py
+++ b/powerline/vim.py
@@ -52,7 +52,31 @@ class VimPowerline(Powerline):
 		super(VimPowerline, self).init('vim', **kwargs)
 		self.last_window_id = 1
 		self.pyeval = pyeval
-		self.window_statusline = '%!' + pyeval + '(\'powerline.statusline({0})\')'
+		self.construct_window_statusline = self.create_window_statusline_constructor()
+
+	if sys.version_info < (3,):
+		def create_window_statusline_constructor(self):
+			window_statusline = b'%!' + str(self.pyeval) + b'(\'powerline.statusline({0})\')'
+			return window_statusline.format
+	else:
+		def create_window_statusline_constructor(self):
+			startstr = b'%!' + self.pyeval.encode('ascii') + b'(\'powerline.statusline('
+			endstr = b')\')'
+			return lambda idx: (
+				startstr + str(idx).encode('ascii') + endstr
+			)
+
+	create_window_statusline_constructor.__doc__ = (
+		'''Create function which returns &l:stl value being given window index
+
+		Created function must return :py:class:`bytes` instance because this is 
+		what ``window.options['statusline']`` returns (``window`` is 
+		:py:class:`vim.Window` instance).
+
+		:return:
+			Function with type ``int → bytes``.
+		'''
+	)
 
 	default_log_stream = sys.stdout
 
@@ -174,7 +198,7 @@ class VimPowerline(Powerline):
 			pyeval = 'PowerlinePyeval'
 
 		self.pyeval = pyeval
-		self.window_statusline = '%!' + pyeval + '(\'powerline.statusline({0})\')'
+		self.construct_window_statusline = self.create_window_statusline_constructor()
 
 		self.update_renderer()
 		__main__.powerline = self
@@ -240,14 +264,14 @@ class VimPowerline(Powerline):
 					curwindow_id = self.last_window_id
 					self.last_window_id += 1
 					window.vars['powerline_window_id'] = curwindow_id
-				statusline = self.window_statusline.format(curwindow_id)
+				statusline = self.construct_window_statusline(curwindow_id)
 				if window.options['statusline'] != statusline:
 					window.options['statusline'] = statusline
 				if curwindow_id == window_id if window_id else window is vim.current.window:
 					r = (window, curwindow_id, window.number)
 			return r
 	else:
-		_vim_getwinvar = staticmethod(vim_get_func('getwinvar'))
+		_vim_getwinvar = staticmethod(vim_get_func('getwinvar', 'bytes'))
 		_vim_setwinvar = staticmethod(vim_get_func('setwinvar'))
 
 		def win_idx(self, window_id):
@@ -260,7 +284,7 @@ class VimPowerline(Powerline):
 					curwindow_id = self.last_window_id
 					self.last_window_id += 1
 					self._vim_setwinvar(winnr, 'powerline_window_id', curwindow_id)
-				statusline = self.window_statusline.format(curwindow_id)
+				statusline = self.construct_window_statusline(curwindow_id)
 				if self._vim_getwinvar(winnr, '&statusline') != statusline:
 					self._vim_setwinvar(winnr, '&statusline', statusline)
 				if curwindow_id == window_id if window_id else window is vim.current.window:
diff --git a/tests/test_foreign_stl_override.vim b/tests/test_foreign_stl_override.vim
new file mode 100644
index 00000000..0cafb558
--- /dev/null
+++ b/tests/test_foreign_stl_override.vim
@@ -0,0 +1,22 @@
+scriptencoding utf-8
+set encoding=utf-8
+let g:powerline_config_paths = [expand('<sfile>:p:h:h') . '/powerline/config_files']
+set laststatus=2
+redir => g:messages
+	try
+		source powerline/bindings/vim/plugin/powerline.vim
+		redrawstatus!
+		vsplit
+		redrawstatus!
+		setlocal statusline=«»
+		redrawstatus!
+	catch
+		call writefile(['Unexpected exception', v:exception], 'message.fail')
+		cquit
+	endtry
+redir END
+if g:messages =~# '\v\S'
+	call writefile(['Unexpected messages'] + split(g:messages, "\n", 1), 'message.fail')
+	cquit
+endif
+qall!