don't try to decode already unicode

* includes tests for decoding charset

aprslib/parse.py

@@ -79,15 +79,16 @@ def parse(packet):
     """
 
     # attempt to detect encoding
-    try:
-        packet = packet.decode('utf-8')
-    except UnicodeDecodeError:
-        res = chardet.detect(packet)
+    if isinstance(packet, str):
+        try:
+            packet = packet.decode('utf-8')
+        except UnicodeDecodeError:
+            res = chardet.detect(packet)
 
-        if res['confidence'] > 0.7:
-            packet = packet.decode(res['encoding'])
-        else:
-            packet = packet.decode('latin-1')
+            if res['confidence'] > 0.7:
+                packet = packet.decode(res['encoding'])
+            else:
+                packet = packet.decode('latin-1')
 
     packet = packet.rstrip("\r\n")
     logger.debug("Parsing: %s", packet)

req.txt

@@ -2,3 +2,4 @@ pylint
 nose
 coverage
 mox
+chardet

tests/test_parse.py

@@ -0,0 +1,36 @@
+# encoding: utf-8
+
+import unittest
+
+from aprslib.parse import parse
+
+
+class ParseTestCase(unittest.TestCase):
+    def test_unicode(self):
+        # 7bit ascii
+        result = parse("A>B:>status")
+
+        self.assertIsInstance(result['status'], unicode)
+        self.assertEqual(result['status'], u"status")
+
+        # string with degree sign
+        result = parse("A>B:>status\xb0")
+
+        self.assertIsInstance(result['status'], unicode)
+        self.assertEqual(result['status'], u"status\xb0")
+
+        # str with unicode
+        result = parse("A>B:>статус")
+
+        self.assertIsInstance(result['status'], unicode)
+        self.assertEqual(result['status'], u"статус")
+
+        # uncide input
+        result = parse(u"A>B:>статус")
+
+        self.assertIsInstance(result['status'], unicode)
+        self.assertEqual(result['status'], u"статус")
+
+
+if __name__ == '__main__':
+    unittest.main()