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 5321 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@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/git-send-email.txt | 11 +++++++----
git-send-email.perl | 12 +++++++-----
t/t9001-send-email.sh | 24 ++++++++++++++++++++++++
3 files changed, 38 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..a76953c310 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..6cdcbcb19e 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -456,6 +456,30 @@ test_expect_success $PREREQ 'allow long lines with --no-validate' '
2>errors
'
+test_expect_success $PREREQ 'short lines with auto encoding are 8bit' '
+ clean_fake_sendmail &&
+ git send-email \
+ --from="A <author@xxxxxxxxxxx>" \
+ --to=nobody@xxxxxxxxxxx \
+ --smtp-server="$(pwd)/fake.sendmail" \
+ --transfer-encoding=auto \
+ $patches &&
+ grep "Content-Transfer-Encoding: 8bit" msgtxt1
+'
+
+test_expect_success $PREREQ 'long lines with auto encoding are quoted-printable' '
+ clean_fake_sendmail &&
+ git send-email \
+ --from="Example <nobody@xxxxxxxxxxx>" \
+ --to=nobody@xxxxxxxxxxx \
+ --smtp-server="$(pwd)/fake.sendmail" \
+ --transfer-encoding=auto \
+ --no-validate \
+ longline.patch \
+ 2>errors &&
+ grep "Content-Transfer-Encoding: quoted-printable" msgtxt1
+'
+
test_expect_success $PREREQ 'Invalid In-Reply-To' '
clean_fake_sendmail &&
git send-email \
