[PATCH v2 1/4] send-email: add an auto option for transfer encoding
- From
brian m. carlson <sandals@crustytoothpaste.net>
- Date
- Jul 8, 2018, 22:17 UTC
- Message-ID
- <20180708221713.518276-2-sandals@crustytoothpaste.net>
- In-Reply-To
- <20180708221713.518276-1-sandals@crustytoothpaste.net>
For most patches, using a transfer encoding of 8bit provides good compatibility with most servers and makes it as easy as possible to view patches. However, there are some patches for which 8bit is not a valid encoding: RFC 5322 specifies that a message must not have lines exceeding 998 octets.
Add a transfer encoding value, auto, which indicates that a patch should use 8bit where allowed and quoted-printable otherwise. Choose quoted-printable instead of base64, since base64-encoded plain text is treated as suspicious by some spam filters.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> --- Documentation/git-send-email.txt | 11 +++++++---- git-send-email.perl | 12 +++++++----- t/t9001-send-email.sh | 23 +++++++++++++++++++++++ 3 files changed, 37 insertions(+), 9 deletions(-)
diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt index 4f3efde80c..385c7de9e2 100644 --- a/Documentation/git-send-email.txt +++ b/Documentation/git-send-email.txt @@ -137,15 +137,18 @@ Note that no attempts whatsoever are made to validate the encoding. Specify encoding of compose message. Default is the value of the 'sendemail.composeencoding'; if that is unspecified, UTF-8 is assumed. ---transfer-encoding=(7bit|8bit|quoted-printable|base64):: +--transfer-encoding=(7bit|8bit|quoted-printable|base64|auto):: Specify the transfer encoding to be used to send the message over SMTP. 7bit will fail upon encountering a non-ASCII message. quoted-printable can be useful when the repository contains files that contain carriage returns, but makes the raw patch email file (as saved from a MUA) much harder to inspect manually. base64 is even more fool proof, but also - even more opaque. Default is the value of the `sendemail.transferEncoding` - configuration value; if that is unspecified, git will use 8bit and not - add a Content-Transfer-Encoding header. + even more opaque. auto will use 8bit when possible, and quoted-printable + otherwise. ++ +Default is the value of the `sendemail.transferEncoding` configuration +value; if that is unspecified, git will use 8bit and not add a +Content-Transfer-Encoding header. --xmailer:: --no-xmailer:: diff --git a/git-send-email.perl b/git-send-email.perl index 8ec70e58ed..1736a09d21 100755 --- a/git-send-email.perl +++ b/git-send-email.perl @@ -1739,9 +1739,8 @@ sub process_file { } if (defined $target_xfer_encoding) { $xfer_encoding = '8bit' if not defined $xfer_encoding; - $message = apply_transfer_encoding( + ($message, $xfer_encoding) = apply_transfer_encoding( $message, $xfer_encoding, $target_xfer_encoding); - $xfer_encoding = $target_xfer_encoding; } if (defined $xfer_encoding) { push @xh, "Content-Transfer-Encoding: $xfer_encoding"; @@ -1852,13 +1851,16 @@ sub apply_transfer_encoding { $message = MIME::Base64::decode($message) if ($from eq 'base64'); + $to = ($message =~ /.{999,}/) ? 'quoted-printable' : '8bit' + if $to eq 'auto'; + die __("cannot send message as 7bit") if ($to eq '7bit' and $message =~ /[^[:ascii:]]/); - return $message + return ($message, $to) if ($to eq '7bit' or $to eq '8bit'); - return MIME::QuotedPrint::encode($message, "\n", 0) + return (MIME::QuotedPrint::encode($message, "\n", 0), $to) if ($to eq 'quoted-printable'); - return MIME::Base64::encode($message, "\n") + return (MIME::Base64::encode($message, "\n"), $to) if ($to eq 'base64'); die __("invalid transfer encoding"); } diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh index e80eacbb1b..a35cba6a4c 100755 --- a/t/t9001-send-email.sh +++ b/t/t9001-send-email.sh @@ -456,6 +456,29 @@ test_expect_success $PREREQ 'allow long lines with --no-validate' ' 2>errors ' +test_expect_success $PREREQ 'short lines with auto encoding are 8bit' ' + clean_fake_sendmail && + git send-email \ + --from="A <author@example.com>" \ + --to=nobody@example.com \ + --smtp-server="$(pwd)/fake.sendmail" \ + --transfer-encoding=auto \ + $patches && + grep "Content-Transfer-Encoding: 8bit" msgtxt1 +' + +test_expect_success $PREREQ 'long lines with auto encoding are quoted-printable' ' + clean_fake_sendmail && + git send-email \ + --from="Example <nobody@example.com>" \ + --to=nobody@example.com \ + --smtp-server="$(pwd)/fake.sendmail" \ + --transfer-encoding=auto \ + --no-validate \ + longline.patch && + grep "Content-Transfer-Encoding: quoted-printable" msgtxt1 +' + test_expect_success $PREREQ 'Invalid In-Reply-To' ' clean_fake_sendmail && git send-email \