lei q|lcat: support "-f reply" output format

When composing replies in "git format-patch" cover letters,
I'd been relying on "lei q -f text ...", but that still requires
several steps to make it suitable for composing a reply:

	* s/^/> / to quote the body
	* drop existing In-Reply-To+References
	* s/^Message-ID:/In-Reply-To:/;
	* add an attribute line
	...

"lei q -f reply" takes care of most of that and users will
only have to trim "From " lines, unnecessary results and
over-quoted text (and trimming is likely less error-prone
than doing all the steps above manually).

This should also be a good replacement for
"git format-patch --in-reply-to=...", since copying long
Message-IDs can be error-prone (and this lets you include
quoted text in replies).

1 files changed, 14 insertions, 0 deletions

diff --git a/t/lei-lcat.t b/t/lei-lcat.t
index e5f00706..31a84744 100644
--- a/t/lei-lcat.t
+++ b/t/lei-lcat.t
@@ -11,6 +11,20 @@ test_lei(sub {
         lei_ok('import', 't/plack-qp.eml');
         lei_ok([qw(lcat --stdin)], undef, { 0 => \$in, %$lei_opt });
         like($lei_out, qr/qp\@example\.com/, 'got a result');
+
+        # test Link:, -f reply, and implicit --stdin:
+        my $prev = $lei_out;
+        $in = "\nLink: https://example.com/foo/qp\@example.com/\n";
+        lei_ok([qw(lcat -f reply)], undef, { 0 => \$in, %$lei_opt});
+        my $exp = <<'EOM';
+To: qp@example.com
+Subject: Re: QP
+In-Reply-To: <qp@example.com>
+
+On some unknown date, qp wrote:
+> hi = bye
+EOM
+        like($lei_out, qr/\AFrom [^\n]+\n\Q$exp\E/sm, '-f reply works');
 });
 
 done_testing;