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author | Krzysztof Wojcik <wojcikk2903@users.noreply.github.com> | 2019-05-14 16:55:23 (GMT) |
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committer | Victor Stinner <vstinner@redhat.com> | 2019-05-14 16:55:23 (GMT) |
commit | c1f5667be1e3ec5871560c677402c1252c6018a6 (patch) | |
tree | 199ab3f8a68ef855b41a086ce280faff1ca817bf /Lib/email | |
parent | 4d45a3b1107977baba9dce868e80d1d95bce4085 (diff) | |
download | cpython-c1f5667be1e3ec5871560c677402c1252c6018a6.zip cpython-c1f5667be1e3ec5871560c677402c1252c6018a6.tar.gz cpython-c1f5667be1e3ec5871560c677402c1252c6018a6.tar.bz2 |
bpo-33529, email: Fix infinite loop in email header encoding (GH-12020)
Diffstat (limited to 'Lib/email')
-rw-r--r-- | Lib/email/_header_value_parser.py | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/Lib/email/_header_value_parser.py b/Lib/email/_header_value_parser.py index bb26d5a..60d0d32 100644 --- a/Lib/email/_header_value_parser.py +++ b/Lib/email/_header_value_parser.py @@ -2723,16 +2723,19 @@ def _fold_as_ew(to_encode, lines, maxlen, last_ew, ew_combine_allowed, charset): lines.append(' ') # XXX We'll get an infinite loop here if maxlen is <= 7 continue - first_part = to_encode[:text_space] - ew = _ew.encode(first_part, charset=encode_as) - excess = len(ew) - remaining_space - if excess > 0: - # encode always chooses the shortest encoding, so this - # is guaranteed to fit at this point. - first_part = first_part[:-excess] - ew = _ew.encode(first_part) - lines[-1] += ew - to_encode = to_encode[len(first_part):] + + to_encode_word = to_encode[:text_space] + encoded_word = _ew.encode(to_encode_word, charset=encode_as) + excess = len(encoded_word) - remaining_space + while excess > 0: + # Since the chunk to encode is guaranteed to fit into less than 100 characters, + # shrinking it by one at a time shouldn't take long. + to_encode_word = to_encode_word[:-1] + encoded_word = _ew.encode(to_encode_word, charset=encode_as) + excess = len(encoded_word) - remaining_space + lines[-1] += encoded_word + to_encode = to_encode[len(to_encode_word):] + if to_encode: lines.append(' ') new_last_ew = len(lines[-1]) |