[New-bugs-announce] [issue22666] email.Header no encoding of unicode strings containing newlines

[Flavio Grossi]

New submission from Flavio Grossi:

When trying to encode an email header with a newline in it, correct encoding is done only for strings and not for unicode strings.
In fact, for unicode strings, encoding is only done if a non ascii character is contained in it.

The attached patch should fix the problem.

Simple example to reproduce the problem:
>>> from email.Header import Header as H

# correctly encoded
>>> H('two\r\nlines', 'utf-8').encode()
'=?utf-8?q?two=0D=0Alines?='

# unicode string not encoded
>>> H(u'two\r\nlines', 'utf-8').encode()
'two\r\nlines'

# unicode string with non ascii chars, correctly encoded
>>> H(u'two\r\nlines and \xe0', 'utf-8').encode()
'=?utf-8?b?dHdvDQpsaW5lcyBhbmQgw6A=?='

----------
components: email
files: fix_email_header_encoding_uses_ascii_before_selected_charset.diff
keywords: patch
messages: 229640
nosy: barry, flavio, r.david.murray
priority: normal
severity: normal
status: open
title: email.Header no encoding of unicode strings containing newlines
type: behavior
versions: Python 2.7
Added file: http://bugs.python.org/file36959/fix_email_header_encoding_uses_ascii_before_selected_charset.diff

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue22666>
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