[fix] multilingual duckduckgo

only works if both country and language are set

searx/engines/duckduckgo.py

  @parse       url, title, content
 
  @todo        rewrite to api
- @todo        language support
-              (the current used site does not support language-change)
 """
 
 from urllib import urlencode
     offset = (params['pageno'] - 1) * 30
 
     if params['language'] == 'all':
-        locale = 'en-us'
+        locale = None
     else:
-        locale = params['language'].replace('_', '-').lower()
-
-    params['url'] = url.format(
-        query=urlencode({'q': query, 'kl': locale}),
-        offset=offset)
+        locale = params['language'].split('_')
+        if len(locale) == 2:
+            # country code goes first
+            locale = locale[1].lower() + '-' + locale[0].lower()
+        else:
+            # doesn't actually do anything because ddg requires both country and language
+            locale = locale[0].lower()
+
+    if locale:
+        params['url'] = url.format(
+            query=urlencode({'q': query, 'kl': locale}), offset=offset)
+    else:
+        params['url'] = url.format(
+            query=urlencode({'q': query}), offset=offset)
 
     return params
 

tests/unit/engines/test_duckduckgo.py

         query = 'test_query'
         dicto = defaultdict(dict)
         dicto['pageno'] = 1
-        dicto['language'] = 'fr_FR'
+        dicto['language'] = 'de_CH'
         params = duckduckgo.request(query, dicto)
         self.assertIn('url', params)
         self.assertIn(query, params['url'])
         self.assertIn('duckduckgo.com', params['url'])
-        self.assertIn('fr-fr', params['url'])
-
-        dicto['language'] = 'all'
-        params = duckduckgo.request(query, dicto)
-        self.assertIn('en-us', params['url'])
+        self.assertIn('ch-de', params['url'])
 
     def test_response(self):
         self.assertRaises(AttributeError, duckduckgo.response, None)