Subject: [PATCH v2 1/5] t9300: demonstrate bug with get-mark and empty orphan commits

From: Elijah Newren <[email-masked]>
Date: Mon, 1 Apr 2019 09:00:07 -0700

Signed-off-by: Elijah Newren <[email-masked]>
---
 Documentation/git-fast-import.txt |  7 +++++-
 t/t9300-fast-import.sh            | 37 +++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index 43ab3b1637..339b6e7e98 100644
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -422,7 +422,12 @@ However it is recommended that a `filedeleteall` command precede
 all `filemodify`, `filecopy`, `filerename` and `notemodify` commands in
 the same commit, as `filedeleteall` wipes the branch clean (see below).
 
-The `LF` after the command is optional (it used to be required).
+The `LF` after the command is optional (it used to be required).  Note
+that for reasons of backward compatibility, if the commit ends with a
+`data` command (i.e. it has has no `from`, `merge`, `filemodify`,
+`filedelete`, `filecopy`, `filerename`, `filedeleteall` or
+`notemodify` commands) then two `LF` commands may appear at the end of
+the command instead of just one.
 
 `author`
 ^^^^^^^^
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 59a13b6a77..c304c8c47c 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -3262,4 +3262,41 @@ test_expect_success PIPE 'V: checkpoint updates tags after tag' '
 	background_import_still_running
 '
 
+###
+### series W (get-mark and empty orphan commits)
+###
+
+cat >>W-input <<-W_INPUT_END
+	commit refs/heads/W-branch
+	mark :1
+	author Full Name <[email-masked]> 1000000000 +0100
+	committer Full Name <[email-masked]> 1000000000 +0100
+	data 27
+	Intentionally empty commit
+	LFsget-mark :1
+	W_INPUT_END
+
+test_expect_failure !MINGW 'W: get-mark & empty orphan commit with no newlines' '
+	sed -e s/LFs// W-input | tr L "\n" | git fast-import
+'
+
+test_expect_failure !MINGW 'W: get-mark & empty orphan commit with one newline' '
+	sed -e s/LFs/L/ W-input | tr L "\n" | git fast-import
+'
+
+test_expect_success !MINGW 'W: get-mark & empty orphan commit with ugly second newline' '
+	# Technically, this should fail as it has too many linefeeds
+	# according to the grammar in fast-import.txt.  But, for whatever
+	# reason, it works.  Since using the correct number of newlines
+	# does not work with older (pre-2.22) versions of git, allow apps
+	# that used this second-newline workaround to keep working by
+	# checking it with this test...
+	sed -e s/LFs/LL/ W-input | tr L "\n" | git fast-import
+'
+
+test_expect_success !MINGW 'W: get-mark & empty orphan commit with erroneous third newline' '
+	# ...but do NOT allow more empty lines than that (see previous test).
+	sed -e s/LFs/LLL/ W-input | tr L "\n" | test_must_fail git fast-import
+'
+
 test_done
-- 
2.21.0.1.g0a561c1dbd