send-email: add an auto option for transfer encoding
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> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson committed
Jul 8, 2018 at 22:17 UTC
7a36987ffffa59052723ed7299c1de25bc18048a
3 files changed
+37
-9
Documentation/git-send-email.txt
+7
-4
@@ -137,15 +137,18 @@ Note that no attempts whatsoever are made to validate the encoding.
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Specify encoding of compose message. Default is the value of the
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'sendemail.composeencoding'; if that is unspecified, UTF-8 is assumed.
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---transfer-encoding=(7bit|8bit|quoted-printable|base64)::
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+--transfer-encoding=(7bit|8bit|quoted-printable|base64|auto)::
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Specify the transfer encoding to be used to send the message over SMTP.
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7bit will fail upon encountering a non-ASCII message. quoted-printable
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can be useful when the repository contains files that contain carriage
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returns, but makes the raw patch email file (as saved from a MUA) much
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harder to inspect manually. base64 is even more fool proof, but also
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- even more opaque. Default is the value of the `sendemail.transferEncoding`
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- configuration value; if that is unspecified, git will use 8bit and not
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- add a Content-Transfer-Encoding header.
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+ even more opaque. auto will use 8bit when possible, and quoted-printable
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+ otherwise.
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++
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+Default is the value of the `sendemail.transferEncoding` configuration
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+value; if that is unspecified, git will use 8bit and not add a
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+Content-Transfer-Encoding header.
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--xmailer::
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--no-xmailer::
git-send-email.perl
+7
-5
@@ -1739,9 +1739,8 @@ sub process_file {
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}
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if (defined $target_xfer_encoding) {
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$xfer_encoding = '8bit' if not defined $xfer_encoding;
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- $message = apply_transfer_encoding(
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+ ($message, $xfer_encoding) = apply_transfer_encoding(
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$message, $xfer_encoding, $target_xfer_encoding);
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- $xfer_encoding = $target_xfer_encoding;
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}
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if (defined $xfer_encoding) {
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push @xh, "Content-Transfer-Encoding: $xfer_encoding";
@@ -1852,13 +1851,16 @@ sub apply_transfer_encoding {
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$message = MIME::Base64::decode($message)
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if ($from eq 'base64');
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+ $to = ($message =~ /.{999,}/) ? 'quoted-printable' : '8bit'
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+ if $to eq 'auto';
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+
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die __("cannot send message as 7bit")
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if ($to eq '7bit' and $message =~ /[^[:ascii:]]/);
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- return $message
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+ return ($message, $to)
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if ($to eq '7bit' or $to eq '8bit');
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- return MIME::QuotedPrint::encode($message, "\n", 0)
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+ return (MIME::QuotedPrint::encode($message, "\n", 0), $to)
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if ($to eq 'quoted-printable');
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- return MIME::Base64::encode($message, "\n")
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+ return (MIME::Base64::encode($message, "\n"), $to)
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if ($to eq 'base64');
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die __("invalid transfer encoding");
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}
t/t9001-send-email.sh
+23
@@ -456,6 +456,29 @@ test_expect_success $PREREQ 'allow long lines with --no-validate' '
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2>errors
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'
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+test_expect_success $PREREQ 'short lines with auto encoding are 8bit' '
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+ clean_fake_sendmail &&
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+ git send-email \
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+ --from="A <author@example.com>" \
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+ --to=nobody@example.com \
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+ --smtp-server="$(pwd)/fake.sendmail" \
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+ --transfer-encoding=auto \
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+ $patches &&
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+ grep "Content-Transfer-Encoding: 8bit" msgtxt1
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+'
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+
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+test_expect_success $PREREQ 'long lines with auto encoding are quoted-printable' '
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+ clean_fake_sendmail &&
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+ git send-email \
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+ --from="Example <nobody@example.com>" \
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+ --to=nobody@example.com \
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+ --smtp-server="$(pwd)/fake.sendmail" \
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+ --transfer-encoding=auto \
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+ --no-validate \
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+ longline.patch &&
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+ grep "Content-Transfer-Encoding: quoted-printable" msgtxt1
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+'
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+
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test_expect_success $PREREQ 'Invalid In-Reply-To' '
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clean_fake_sendmail &&
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git send-email \