[PATCH v5 0/4] imap-send: fix with reordered message headers

git imap-send rejected patches sent with git send-email, such as ones fetched from lore with b4, because it expected Date before Subject.

Changes in v5:

 * End the header block at an empty line in a CRLF mbox as well, so headers
   in the body or in later messages no longer count. Add a test.

Changes in v4:

 * Store the tunnel as an allocated pointer, so it is only finished when it
   was started, and drop the local tunnel variable
 * Add a test for lowercase from:, date: and subject: headers
 * Explain in the commit message why dropping the From git-send-email
   special case is fine for mboxes written by other scripts

Changes in v3:

 * Split concerns into different commits, commit message explains what they
   do.
 * Handle tunnel leak in the proper place.

Changes in v2:

 * Case insensitive header match according to RFC 822/2822/5322.

Harald Nordgren (4):
  imap-send: wait for the tunnel command to finish
  imap-send: accept messages with Subject before Date
  imap-send: check git send-email copies like other messages
  imap-send: match header names case insensitively

 imap-send.c           | 61 ++++++++++++++++++++-------------------
 t/t9001-send-email.sh | 66 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 98 insertions(+), 29 deletions(-)

base-commit: 50fe5cc63f9cd6e89b87a2c9ccf96a444f4cfdb7
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2456%2FHaraldNordgren%2Ffix%2Fimap-send-header-order-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2456/HaraldNordgren/fix/imap-send-header-order-v5
Pull-Request: https://github.com/git/git/pull/2456

Range-diff vs v4:

 1:  8941ae12bb = 1:  cb27ac3a27 imap-send: wait for the tunnel command to finish
 2:  ad3158b336 ! 2:  fa90c64a5c imap-send: accept messages with Subject before Date
     @@ Commit message
          and git send-email writes Subject before Date.
      
          Accept the three headers in any order within the header block of each
     -    message.
     +    message, which ends at the first empty line whether the mbox uses LF or
     +    CRLF line endings.
      
          Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
      
     @@ imap-send.c: static void wrap_in_html(struct strbuf *msg)
      +{
      +	bool from = false, date = false, subject = false;
      +
     -+	while ((line = strchr(line, '\n')) && *++line != '\n') {
     ++	while ((line = strchr(line, '\n')) &&
     ++	       *++line != '\n' && !starts_with(line, "\r\n")) {
      +		if (starts_with(line, "From: "))
      +			from = true;
      +		else if (starts_with(line, "Date: "))
     @@ t/t9001-send-email.sh: test_expect_success $PREREQ '--compose handles to headers
      +	test_grep "^Sending 1 message to INBOX folder" err &&
      +	test_grep "(1/1) done" err
      +'
     ++
     ++test_expect_success $PREREQ 'imap-send ignores headers in the body of a CRLF mbox' '
     ++	test_config imap.tunnel ./fake-imap-server &&
     ++	q_to_cr >crlf.mbox <<-\EOF &&
     ++	From mboxrd@z Thu Jan  1 00:00:00 1970Q
     ++	From: Example <from@example.com>Q
     ++	Subject: Fwd: originalQ
     ++	Q
     ++	---------- Forwarded message ---------Q
     ++	From: Someone <someone@example.com>Q
     ++	Date: Thu, 1 Jan 1970 00:00:00 +0000Q
     ++	Subject: originalQ
     ++	EOF
     ++	test_must_fail git imap-send --folder=INBOX <crlf.mbox 2>err &&
     ++	test_grep "no messages found to send" err
     ++'
      +
       test_done
 3:  919e38c31d ! 3:  8646185486 imap-send: check git send-email copies like other messages
     @@ imap-send.c: static int count_messages(struct strbuf *all_msgs)
       			break;
      
       ## t/t9001-send-email.sh ##
     -@@ t/t9001-send-email.sh: test_expect_success $PREREQ 'imap-send accepts a sent patch from the list archiv
     - 	test_grep "(1/1) done" err
     +@@ t/t9001-send-email.sh: test_expect_success $PREREQ 'imap-send ignores headers in the body of a CRLF mbo
     + 	test_grep "no messages found to send" err
       '
       
      +test_expect_success $PREREQ '--imap-sent-folder stores a copy of the sent patch' '
 4:  5b4a08bbda ! 4:  e7d1d7cd72 imap-send: match header names case insensitively
     @@ Commit message
      
       ## imap-send.c ##
      @@ imap-send.c: static bool has_required_headers(const char *line)
     - 	bool from = false, date = false, subject = false;
       
     - 	while ((line = strchr(line, '\n')) && *++line != '\n') {
     + 	while ((line = strchr(line, '\n')) &&
     + 	       *++line != '\n' && !starts_with(line, "\r\n")) {
      -		if (starts_with(line, "From: "))
      +		if (istarts_with(line, "From: "))
       			from = true;