Python checker: new option g:syntastic_python_python_use_codec (@delfick).

The new option tells the checket to load the file in memory and look for
a comment line "# coding: <codec>".  If found, the named codec is used
to decode the file before checking.  This makes sense only if said codec
doesn't change the line numbers of the initial file.  An example of such
codec is "spec" provided by the "Nose of Yeti" library:

https://github.com/delfick/nose-of-yeti

plugin/syntastic.vim

@@ -19,7 +19,7 @@ if has('reltime')
     lockvar! g:_SYNTASTIC_START
 endif
 
-let g:_SYNTASTIC_VERSION = '3.5.0-72'
+let g:_SYNTASTIC_VERSION = '3.5.0-146'
 lockvar g:_SYNTASTIC_VERSION
 
 " Sanity checks {{{1

syntax_checkers/python/codec.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python
+
+from __future__ import print_function
+from sys import argv, exit
+
+import codecs
+import re
+import os
+
+
+if len(argv) != 2:
+    exit(1)
+
+try:
+    with open(argv[1]) as fle:
+        text = fle.readlines()
+
+    if text:
+        match = re.match(r"#\s*coding\s*:\s*(?P<coding>\w+)", text[0])
+        if match:
+            text = codecs.lookup(match.groupdict()["coding"]).incrementaldecoder().decode(
+                ''.join(text).encode('utf-8')).encode('utf-8')
+
+    if isinstance(text, list):
+        text = ''.join(text).encode('utf-8')
+
+    compile(text, argv[1], 'exec', 0, 1)
+except SyntaxError as err:
+    print('%s:%s:%s: %s' % (err.filename, err.lineno, err.offset, err.msg))
+except Exception as err:
+    print('%s:%s:%s: %s' % (os.path.abspath(argv[1]), 1, 0, err))

syntax_checkers/python/python.vim

@@ -15,10 +15,14 @@ if exists("g:loaded_syntastic_python_python_checker")
 endif
 let g:loaded_syntastic_python_python_checker = 1
 
+if !exists('g:syntastic_python_python_use_codec')
+    let g:syntastic_python_python_use_codec = 0
+endif
+
 let s:save_cpo = &cpo
 set cpo&vim
 
-let s:compiler = expand('<sfile>:p:h', 1) . syntastic#util#Slash() . 'compile.py'
+let s:base_path = expand('<sfile>:p:h', 1) . syntastic#util#Slash()
 
 function! SyntaxCheckers_python_python_IsAvailable() dict
     if !executable(self.getExec())
@@ -32,7 +36,9 @@ function! SyntaxCheckers_python_python_IsAvailable() dict
 endfunction
 
 function! SyntaxCheckers_python_python_GetLocList() dict
-    let makeprg = self.makeprgBuild({ 'exe': [self.getExec(), s:compiler] })
+    let compiler = s:base_path . (g:syntastic_python_python_use_codec ? 'codec.py' : 'compile.py')
+    call self.log('using compiler script', compiler)
+    let makeprg = self.makeprgBuild({ 'exe': [self.getExec(), compiler] })
 
     let errorformat = '%E%f:%l:%c: %m'