db/utils: decoded_headers will be passed str not bytes

I had made the assumption early on that this would get bytes, but when I
added `assert isinstance(header, bytes)` alot would crash on startup,
changing `bytes` to `str` fixed that. I noticed this when trying to fix
the warning generated in the logging call.

2 files changed, 12 insertions, 22 deletions

diff --git a/alot/db/utils.py b/alot/db/utils.py
index 4f533306..5303320c 100644
--- a/alot/db/utils.py
+++ b/alot/db/utils.py
@@ -421,30 +421,20 @@ def decode_header(header, normalize=False):
     This turns it into a single unicode string
 
     :param header: the header value
-    :type header: bytes
+    :type header: str
     :param normalize: replace trailing spaces after newlines
     :type normalize: bool
     :rtype: str
     """
-    # FIXME: this is just hacked until it works, mostly
-
-    # If the value isn't ascii as RFC2822 prescribes,
-    # we just return the unicode bytestring as is
-    value = string_decode(header)  # convert to unicode
-    try:
-        value = value.encode('ascii')
-    except UnicodeEncodeError:
-        return value
-
     # some mailers send out incorrectly escaped headers
     # and double quote the escaped realname part again. remove those
     # RFC: 2047
-    regex = br'"(=\?.+?\?.+?\?[^ ?]+\?=)"'
-    value = re.sub(regex, br'\1', value)
-    logging.debug(b"unquoted header: |%s|", value)
+    regex = r'"(=\?.+?\?.+?\?[^ ?]+\?=)"'
+    value = re.sub(regex, r'\1', header)
+    logging.debug("unquoted header: |%s|", value)
 
     # otherwise we interpret RFC2822 encoding escape sequences
-    valuelist = email.header.decode_header(value.decode('ascii'))
+    valuelist = email.header.decode_header(value)
     decoded_list = []
     for v, enc in valuelist:
         v = string_decode(v, enc)
diff --git a/tests/db/utils_test.py b/tests/db/utils_test.py
index e3d3596a..b1187fe3 100644
--- a/tests/db/utils_test.py
+++ b/tests/db/utils_test.py
@@ -248,7 +248,7 @@ class TestDecodeHeader(unittest.TestCase):
         output = b'=?' + encoding.encode('ascii') + b'?Q?'
         for byte in string:
             output += b'=' + codecs.encode(bytes([byte]), 'hex').upper()
-        return output + b'?='
+        return (output + b'?=').decode('ascii')
 
     @staticmethod
     def _base64(unicode_string, encoding):
@@ -263,7 +263,7 @@ class TestDecodeHeader(unittest.TestCase):
         """
         string = unicode_string.encode(encoding)
         b64 = base64.encodebytes(string).strip()
-        return b'=?' + encoding.encode('utf-8') + b'?B?' + b64 + b'?='
+        return (b'=?' + encoding.encode('utf-8') + b'?B?' + b64 + b'?=').decode('ascii')
 
 
     def _test(self, teststring, expected):
@@ -306,17 +306,17 @@ class TestDecodeHeader(unittest.TestCase):
 
     def test_quoted_words_can_be_interrupted(self):
         part = u'ÄÖÜäöü'
-        text = self._base64(part, 'utf-8') + b' and ' + \
+        text = self._base64(part, 'utf-8') + ' and ' + \
             self._quote(part, 'utf-8')
         expected = u'ÄÖÜäöü and ÄÖÜäöü'
         self._test(text, expected)
 
     def test_different_encodings_can_be_mixed(self):
         part = u'ÄÖÜäöü'
-        text = b'utf-8: ' + self._base64(part, 'utf-8') + \
-            b' again: ' + self._quote(part, 'utf-8') + \
-            b' latin1: ' + self._base64(part, 'iso-8859-1') + \
-            b' and ' + self._quote(part, 'iso-8859-1')
+        text = 'utf-8: ' + self._base64(part, 'utf-8') + \
+            ' again: ' + self._quote(part, 'utf-8') + \
+            ' latin1: ' + self._base64(part, 'iso-8859-1') + \
+            ' and ' + self._quote(part, 'iso-8859-1')
         expected = u'utf-8: ÄÖÜäöü again: ÄÖÜäöü latin1: ÄÖÜäöü and ÄÖÜäöü'
         self._test(text, expected)