fast-import: introduce 'done' command

Add a 'done' command that causes fast-import to stop reading from the
stream and exit.

If the new --done command line flag was passed on the command line
(or a "feature done" declaration included at the start of the stream),
make the 'done' command mandatory.  So "git fast-import --done"'s
input format will be prefix-free, making errors easier to detect when
they show up as early termination at some convenient time of the
upstream of a pipe writing to fast-import.

Another possible application of the 'done' command would to be allow a
fast-import stream that is only a small part of a larger encapsulating
stream to be easily parsed, leaving the file offset after the "done\n"
so the other application can pick up from there.  This patch does not
teach fast-import to do that --- fast-import still uses buffered input
(stdio).

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 6b1ba6c858..526231bbeb 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -2197,6 +2197,48 @@ test_expect_success 'R: quiet option results in no stats being output' '
     test_cmp empty output
 '
 
+test_expect_success 'R: feature done means terminating "done" is mandatory' '
+	echo feature done | test_must_fail git fast-import &&
+	test_must_fail git fast-import --done </dev/null
+'
+
+test_expect_success 'R: terminating "done" with trailing gibberish is ok' '
+	git fast-import <<-\EOF &&
+	feature done
+	done
+	trailing gibberish
+	EOF
+	git fast-import <<-\EOF
+	done
+	more trailing gibberish
+	EOF
+'
+
+test_expect_success 'R: terminating "done" within commit' '
+	cat >expect <<-\EOF &&
+	OBJID
+	:000000 100644 OBJID OBJID A	hello.c
+	:000000 100644 OBJID OBJID A	hello2.c
+	EOF
+	git fast-import <<-EOF &&
+	commit refs/heads/done-ends
+	committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+	data <<EOT
+	Commit terminated by "done" command
+	EOT
+	M 100644 inline hello.c
+	data <<EOT
+	Hello, world.
+	EOT
+	C hello.c hello2.c
+	done
+	EOF
+	git rev-list done-ends |
+	git diff-tree -r --stdin --root --always |
+	sed -e "s/$_x40/OBJID/g" >actual &&
+	test_cmp expect actual
+'
+
 cat >input <<EOF
 option git non-existing-option
 EOF