mutt_ldap.py: Add an output-encoding option

This avoids crashing with:

  UnicodeEncodeError: 'ascii' codec can't encode characters

when mutt_ldap.py's stdout is not connected to a terminal (and
therefore doesn't have sys.stdout.encodign set up).

  $ python2.7 -c "print(u'α')" | cat
  Traceback (most recent call last):
    File "<string>", line 1, in <module>
  UnicodeEncodeError: 'ascii' codec can't encode characters in
    position 0-1: ordinal not in range(128)
  $ python2.7 -c 'import sys; print(sys.stdout.encoding)'
  UTF-8
  $ python2.7 -c 'import sys; print(sys.stdout.encoding)' | cat
  None
  $ python3.2 -c "print('α')" | cat
  α
  $ python3.2 -c 'import sys; print(sys.stdout.encoding)'
  UTF-8
  $ python3.2 -c 'import sys; print(sys.stdout.encoding)' | cat
  UTF-8

Both settings should match the value of the Mutt configuration
variable $charset [1,2]:

On Thu, Jan 24, 2013 at 06:25:24PM +0000, Michael Elkins wrote:
> On Thu, Jan 24, 2013 at 12:36:02PM -0500, W. Trevor King wrote:
> > I have a script that queries for address completion using the
> > query_command setting, but the docs are silent on the encoding for
> > the arguments and expected output [1]. ...
>
> It expects the output to be in the same encoding as $charset.
> Mutt performs the RFC2047 encoding automatically.

On Thu, Jan 24, 2013 at 07:00:53PM +0000, Michael Elkins wrote:
> On Thu, Jan 24, 2013 at 01:42:34PM -0500, W. Trevor King wrote:
> > ...Is it also $charset for the argv input?
>
> Yes.

If you don't specify a $charset in your Mutt config, you can probably
get away with not specifying charsets for these config options,
because Mutt's default charset detection will likely match up with
Python's locale.getpreferredencoding().

[1]: http://marc.info/?l=mutt-dev&m=135905197022081&w=2
[2]: http://marc.info/?l=mutt-dev&m=135905407723082&w=2

diff --git a/mutt_ldap.py b/mutt_ldap.py
index f3bb5bae659370b3ff3706072da3045dfed24d47..21a1174da30e1fd3f065852189f2816987222f07 100755 (executable)
--- a/mutt_ldap.py
+++ b/mutt_ldap.py
@@ -60,8 +60,10 @@ CONFIG.set('cache', 'path', '~/.mutt-ldap.cache') # cache results here
 CONFIG.set('cache', 'fields', '')  # fields to cache (if empty, setup in the main block)
 CONFIG.set('cache', 'longevity-days', '14') # TODO: cache results for 14 days by default
 CONFIG.add_section('system')
+# HACK: Python 2.x support, see http://bugs.python.org/issue13329#msg147475
+CONFIG.set('system', 'output-encoding', '')  # match .muttrc's $charset
 # HACK: Python 2.x support, see http://bugs.python.org/issue2128
-CONFIG.set('system', 'argv-encoding', 'utf-8')
+CONFIG.set('system', 'argv-encoding', '')
 
 CONFIG.read(_os_path.expanduser('~/.mutt-ldap.rc'))
 
@@ -264,8 +266,20 @@ def format_entry(entry):
 
 
 if __name__ == '__main__':
+    import codecs as _codecs
+    import locale as _locale
     import sys
 
+    default_encoding = _locale.getpreferredencoding(do_setlocale=True)
+    for key in ['output-encoding', 'argv-encoding']:
+        CONFIG.set(
+            'system', key,
+            CONFIG.get('system', key, raw=True) or default_encoding)
+
+    # HACK: convert sys.stdout to Unicode (not needed in Python 3)
+    output_encoding = CONFIG.get('system', 'output-encoding')
+    sys.stdout = _codecs.getwriter(output_encoding)(sys.stdout)
+
     # HACK: convert sys.argv to Unicode (not needed in Python 3)
     argv_encoding = CONFIG.get('system', 'argv-encoding')
     sys.argv = [unicode(arg, argv_encoding) for arg in sys.argv]