Fix safe_unicode and string unicode library functions

powerline/lib/unicode.py

@@ -100,7 +100,10 @@ def safe_unicode(s):
 	'''
 	try:
 		try:
-			return unicode(s)
+			if type(s) is bytes:
+				return unicode(s, 'ascii')
+			else:
+				return unicode(s)
 		except UnicodeDecodeError:
 			try:
 				return unicode(s, 'utf-8')
@@ -125,11 +128,18 @@ class FailedUnicode(unicode):
 	pass
 
 
-def string(s):
-	if type(s) is not str:
-		return s.encode('utf-8')
-	else:
-		return s
+if sys.version_info < (3,):
+	def string(s):
+		if type(s) is not str:
+			return s.encode('utf-8')
+		else:
+			return s
+else:
+	def string(s):
+		if type(s) is not str:
+			return s.decode('utf-8')
+		else:
+			return s
 
 
 def surrogate_pair_to_character(high, low):

tests/test_lib.py

@@ -448,7 +448,6 @@ class TestUnicode(TestCase):
 		self.assertRaises(TypeError, plu.out_u, None)
 
 	def test_safe_unicode(self):
-		raise SkipTest('safe_unicode() function is buggy')
 		self.assertStringsIdentical('abc', plu.safe_unicode('abc'))
 		self.assertStringsIdentical('abc', plu.safe_unicode(b'abc'))
 		self.assertStringsIdentical('«»', plu.safe_unicode(b'\xc2\xab\xc2\xbb'))
@@ -467,7 +466,6 @@ class TestUnicode(TestCase):
 		self.assertEqual('abc', plu.FailedUnicode('abc'))
 
 	def test_string(self):
-		raise SkipTest('string() function is buggy')
 		self.assertStringsIdentical(str('abc'), plu.string('abc'))
 		self.assertStringsIdentical(str('abc'), plu.string(b'abc'))