Fixing more unicode-related issues.

This is getting really tedious really fast.

python/ycm/utils.py

@@ -27,6 +27,7 @@ import stat
 import json
 from distutils.spawn import find_executable
 import subprocess
+import collections
 
 WIN_PYTHON27_PATH = 'C:\python27\pythonw.exe'
 WIN_PYTHON26_PATH = 'C:\python26\pythonw.exe'
@@ -40,6 +41,7 @@ def SanitizeQuery( query ):
   return query.strip()
 
 
+# Given an object, returns a str object that's utf-8 encoded.
 def ToUtf8IfNeeded( value ):
   if isinstance( value, unicode ):
     return value.encode( 'utf8' )
@@ -48,8 +50,26 @@ def ToUtf8IfNeeded( value ):
   return str( value )
 
 
+# Recurses through the object if it's a dict/iterable and converts all the
+# unicode objects to utf-8 strings.
+def RecursiveEncodeUnicodeToUtf8( value ):
+  if isinstance( value, unicode ):
+    return value.encode( 'utf8' )
+  if isinstance( value, str ):
+    return value
+  elif isinstance( value, collections.Mapping ):
+    return dict( map( RecursiveEncodeUnicodeToUtf8, value.iteritems() ) )
+  elif isinstance( value, collections.Iterable ):
+    return type( value )( map( RecursiveEncodeUnicodeToUtf8, value ) )
+  else:
+    return value
+
+
 def ToUtf8Json( data ):
-  return ToUtf8IfNeeded( json.dumps( data, ensure_ascii = False ) )
+  return json.dumps( RecursiveEncodeUnicodeToUtf8( data ),
+                     ensure_ascii = False,
+                     # This is the encoding of INPUT str data
+                     encoding = 'utf-8' )
 
 
 def PathToTempDir():