From: "\"Jan H. Schönherr\"" <schnhrr@cs.tu-berlin.de>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org, Jeff King <peff@peff.net>
Subject: Re: [PATCH 2/5] format-patch: do not wrap rfc2047 encoded headers too late
Date: Wed, 10 Oct 2012 11:31:59 +0200 [thread overview]
Message-ID: <5075408F.8050502@cs.tu-berlin.de> (raw)
In-Reply-To: <7v7gqzfnpj.fsf@alter.siamese.dyndns.org>
Am 09.10.2012 21:30, schrieb Junio C Hamano:
> Jan H. Schönherr <schnhrr@cs.tu-berlin.de> writes:
...
>> static int is_rfc2047_special(char ch)
>> {
>> + /*
>> + * We encode ' ' using '=20' even though rfc2047
>> + * allows using '_' for readability. Unfortunately,
>> + * many programs do not understand this and just
>> + * leave the underscore in place.
>> + */
>
> The sentence break made me read the above three times to understand
> what it is trying to say. "Unfortunately" refers to what happens if
> we were to use '_', but it initially appeared to be describing some
> bug due to our encoding ' ' as '=20'. Perhaps like this?
>
> /*
> * rfc2047 allows '_' to encode ' ' for readability, but
> * many programs do not understand ...; encode ' ' using
> * '=20' instead to avoid the problem.
> */
I was just moving that comment (and the following check) around,
but I'll update the comment in the next version.
>> + if (ch == ' ' || ch == '\n')
>> + return 1;
>
> The comment justifies why this "if (ch == ' ')", which could be part
> of the "return" below, separately is done, but nothing explains why
> you add '\n' (and not other controls, e.g. '\t') to the mix.
The check for '\n' was introduced in commit c22e7de3
("format-patch: rfc2047-encode newlines in headers").
The commit log was:
These should generally never happen, as we already
concatenate multiples in subjects into a single line. But
let's be defensive, since not encoding them means we will
output malformed headers.
Having again a look at RFC 2047, I see that we should be
even more strict and not allow any non-printable character to
be passed through unencoded. I guess that adds another patch to
the series. Hmm... Maybe I can split patch 4 into two patches,
one that mostly fixes is_rfc2047_special() and one that
avoids 822 quoting when doing 2047 encoding.
>
>> return (non_ascii(ch) || (ch == '=') || (ch == '?') || (ch == '_'));
>> }
>>
>> static void add_rfc2047(struct strbuf *sb, const char *line, int len,
>> const char *encoding)
>> {
>> - static const int max_length = 78; /* per rfc2822 */
>> + static const int max_length = 76; /* per rfc2047 */
>> int i;
>> int line_len;
>>
>> @@ -286,7 +295,7 @@ static void add_rfc2047(struct strbuf *sb, const char *line, int len,
>> if ((i + 1 < len) && (ch == '=' && line[i+1] == '?'))
>> goto needquote;
>> }
>> - strbuf_add_wrapped_bytes(sb, line, len, -line_len, 1, max_length+1);
>> + strbuf_add_wrapped_bytes(sb, line, len, -line_len, 1, 78+1);
>> return;
>
> Yuck. If you do want to retain 78 for non-quoted output for
> backward compatibility, that is OK, but if that is the case, please
> introduce a new constant "max_quoted_length" or something to stand
> for 76 and use it in the "needquote:" part below.
Will do.
Regards
Jan
next prev parent reply other threads:[~2012-10-10 9:32 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-08 17:33 [PATCH 0/5] Cure some format-patch wrapping and encoding issues Jan H. Schönherr
2012-10-08 17:33 ` [PATCH 1/5] format-patch: do not wrap non-rfc2047 headers too early Jan H. Schönherr
2012-10-08 17:33 ` [PATCH 2/5] format-patch: do not wrap rfc2047 encoded headers too late Jan H. Schönherr
[not found] ` <7v7gqzfnpj.fsf@alter.siamese.dyndns.org>
2012-10-10 9:31 ` "Jan H. Schönherr" [this message]
2012-10-08 17:33 ` [PATCH 3/5] format-patch: introduce helper function last_line_length() Jan H. Schönherr
2012-10-08 17:33 ` [PATCH 4/5] format-patch: fix rfc2047 address encoding with respect to rfc822 specials Jan H. Schönherr
2012-10-08 17:33 ` [PATCH 5/5] format-patch: tests: check rfc822+rfc2047 in to+cc headers Jan H. Schönherr
[not found] ` <7v391nfmzn.fsf@alter.siamese.dyndns.org>
2012-10-10 10:44 ` "Jan H. Schönherr"
2012-10-10 17:02 ` Junio C Hamano
[not found] ` <7vfw5nfoq9.fsf@alter.siamese.dyndns.org>
2012-10-10 10:49 ` [PATCH 0/5] Cure some format-patch wrapping and encoding issues "Jan H. Schönherr"
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