Re: [PATCH] send-email: improve RFC2047 quote parsing

[Junio C Hamano <gitster@pobox.com>]

Thomas Rast <trast@student.ethz.ch> writes:

> The RFC2047 unquoting, used to parse email addresses in From and Cc
> headers, is broken in several ways:
>
> * It erroneously substitutes ' ' for '_' in *the whole* header, even
>   outside the quoted field. [Noticed by Christoph.]
>
> * It is too liberal in its matching, and happily matches the start of
>   one quoted chunk against the end of another, or even just something
>   that looks like such an end. [Noticed by Junio.]
>
> * It fundamentally cannot cope with encodings that are not a superset
>   of ASCII, nor several (incompatible) encodings in the same header.
>
> This patch fixes the first two by doing a more careful decoding of the
> =AB outer quoting.  Fixing the fundamental issues is left for a
> future, more intrusive, patch.

What is this =AB thing?

>
> Noticed-by: Christoph Miebach <christoph.miebach@web.de>
> Helped-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Thomas Rast <trast@student.ethz.ch>
> ---
>
> This is the easy part, fixed as per Junio's comment that it needs to
> use a .*? match for the contents, and with a test.

What's the hard part?  Do you mean the "fundamentally cannot" part?

Thanks.

>  git-send-email.perl   | 10 ++++++----
>  t/t9001-send-email.sh | 13 +++++++++++++
>  2 files changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/git-send-email.perl b/git-send-email.perl
> index ef30c55..6647137 100755
> --- a/git-send-email.perl
> +++ b/git-send-email.perl
> @@ -862,11 +862,13 @@ sub make_message_id {
>  sub unquote_rfc2047 {
>  	local ($_) = @_;
>  	my $encoding;
> -	if (s/=\?([^?]+)\?q\?(.*)\?=/$2/g) {
> +	s{=\?([^?]+)\?q\?(.*?)\?=}{
>  		$encoding = $1;
> -		s/_/ /g;
> -		s/=([0-9A-F]{2})/chr(hex($1))/eg;
> -	}
> +		my $e = $2;
> +		$e =~ s/_/ /g;
> +		$e =~ s/=([0-9A-F]{2})/chr(hex($1))/eg;
> +		$e;
> +	}eg;
>  	return wantarray ? ($_, $encoding) : $_;
>  }
>  
> diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
> index 8c12c65..0351228 100755
> --- a/t/t9001-send-email.sh
> +++ b/t/t9001-send-email.sh
> @@ -841,6 +841,19 @@ test_expect_success $PREREQ '--compose adds MIME for utf8 subject' '
>  	grep "^Subject: =?UTF-8?q?utf8-s=C3=BCbj=C3=ABct?=" msgtxt1
>  '
>  
> +test_expect_success $PREREQ 'utf8 author is correctly passed on' '
> +	clean_fake_sendmail &&
> +	test_commit weird_author &&
> +	test_when_finished "git reset --hard HEAD^" &&
> +	git commit --amend --author "Füñný Nâmé <odd_?=mail@example.com>" &&
> +	git format-patch --stdout -1 >funny_name.patch &&
> +	git send-email --from="Example <nobody@example.com>" \
> +	  --to=nobody@example.com \
> +	  --smtp-server="$(pwd)/fake.sendmail" \
> +	  funny_name.patch &&
> +	grep "^From: Füñný Nâmé <odd_?=mail@example.com>" msgtxt1
> +'
> +
>  test_expect_success $PREREQ 'detects ambiguous reference/file conflict' '
>  	echo master > master &&
>  	git add master &&