Fix bytes handling on python3

Fixes #356

powerline/bindings/vim/__init__.py

@@ -1,5 +1,7 @@
 # vim:fileencoding=utf-8:noet
 
+import sys
+
 try:
 	import vim
 except ImportError:
@@ -15,7 +17,10 @@ try:
 	def vim_get_func(f, rettype=None):
 		'''Return a vim function binding.'''
 		try:
-			return vim.bindeval('function("' + f + '")')
+			func = vim.bindeval('function("' + f + '")')
+			if sys.version_info >= (3,) and rettype is str:
+				return (lambda *args, **kwargs: func(*args, **kwargs).decode('utf-8', errors='replace'))
+			return func
 		except vim.error:
 			return None
 except AttributeError:
@@ -47,4 +52,12 @@ except AttributeError:
 
 	vim_get_func = VimFunc
 
+if sys.version_info < (3,) or not hasattr(vim, 'bindeval'):
 	getbufvar = vim_get_func('getbufvar')
+else:
+	_getbufvar = vim_get_func('getbufvar')
+	def getbufvar(*args):
+		r = _getbufvar(*args)
+		if type(r) is bytes:
+			return r.decode('utf-8')
+		return r

powerline/matchers/vim.py

@@ -7,7 +7,7 @@ from powerline.bindings.vim import getbufvar
 
 
 def help(matcher_info):
-	return getbufvar(matcher_info['bufnr'], '&buftype') == 'help'
+	return str(getbufvar(matcher_info['bufnr'], '&buftype')) == 'help'
 
 
 def cmdwin(matcher_info):

powerline/renderers/vim.py

@@ -10,9 +10,7 @@ from powerline.theme import Theme
 import vim
 
 
-vim_mode = vim_get_func('mode')
-vim_getwinvar = vim_get_func('getwinvar')
-vim_setwinvar = vim_get_func('setwinvar')
+vim_mode = vim_get_func('mode', rettype=str)
 mode_translations = {
 	chr(ord('V') - 0x40): '^V',
 	chr(ord('S') - 0x40): '^S',

powerline/segments/vim.py

@@ -19,8 +19,8 @@ from collections import defaultdict
 
 vim_funcs = {
 	'virtcol': vim_get_func('virtcol', rettype=int),
-	'fnamemodify': vim_get_func('fnamemodify'),
-	'expand': vim_get_func('expand'),
+	'fnamemodify': vim_get_func('fnamemodify', rettype=str),
+	'expand': vim_get_func('expand', rettype=str),
 	'bufnr': vim_get_func('bufnr', rettype=int),
 	'line2byte': vim_get_func('line2byte', rettype=int),
 }

tests/vim.py

@@ -31,6 +31,26 @@ def _logged(func):
 	return f
 
 
+def _construct_result(r):
+	import sys
+	if sys.version_info < (3,):
+		return r
+	else:
+		if type(r) is str:
+			return r.encode('utf-8')
+		elif type(r) is dict or type(r) is list:
+			raise NotImplementedError
+		return r
+
+
+def _str_func(func):
+	from functools import wraps
+	@wraps(func)
+	def f(*args, **kwargs):
+		return _construct_result(func(*args, **kwargs))
+	return f
+
+
 def _log_print():
 	import sys
 	for entry in _log:
@@ -75,6 +95,7 @@ def bindeval(expr):
 
 
 @_logged
+@_str_func
 def _emul_mode(*args):
 	if args and args[0]:
 		return _mode
@@ -83,6 +104,7 @@ def _emul_mode(*args):
 
 
 @_logged
+@_str_func
 def _emul_getbufvar(bufnr, varname):
 	if varname[0] == '&':
 		if bufnr not in _buf_options:
@@ -98,6 +120,7 @@ def _emul_getbufvar(bufnr, varname):
 
 
 @_logged
+@_str_func
 def _emul_getwinvar(winnr, varname):
 	return _win_scopes[winnr][varname]
 
@@ -115,6 +138,7 @@ def _emul_virtcol(expr):
 
 
 @_logged
+@_str_func
 def _emul_fnamemodify(path, modstring):
 	import os
 	_modifiers = {
@@ -130,6 +154,7 @@ def _emul_fnamemodify(path, modstring):
 
 
 @_logged
+@_str_func
 def _emul_expand(expr):
 	if expr == '<abuf>':
 		return _buffer()