[PATCH] refs: add \t to reflog in the files backend

["Han-Wen Nienhuys via GitGitGadget" <gitgitgadget@gmail.com>]

From: Han-Wen Nienhuys <hanwen@google.com>

commit 523fa69c3 (Jul 10, 2020) "reflog: cleanse messages in the
refs.c layer" centralized reflog normalizaton.  However, the
normalizaton added a leading "\t" to the message. This is an artifact
of the reflog storage format in the files backend, so it should be
added there.

Routines that parse back the reflog (such as grab_nth_branch_switch)
expect the "\t" to not be in the message, so without this fix, git
with reftable cannot process the "@{-1}" syntax.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
---
    refs: add \t to reflog in the files backend
    
    commit 523fa69c3 (Jul 10, 2020) "reflog: cleanse messages in the refs.c
    layer" centralized reflog normalizaton. However, the normalizaton added
    a leading "\t" to the message. This is an artifact of the reflog storage
    format in the files backend, so it should be added there.
    
    Routines that parse back the reflog (such as grab_nth_branch_switch)
    expect the "\t" to not be in the message, so without this fix, git with
    reftable cannot process the "@{-1}" syntax.
    
    Signed-off-by: Han-Wen Nienhuys hanwen@google.com [hanwen@google.com]

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-688%2Fhanwen%2Ftab-reflog-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-688/hanwen/tab-reflog-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/688

 refs.c               | 1 -
 refs/files-backend.c | 4 +++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/refs.c b/refs.c
index 89814c7be4..2dd851fe81 100644
--- a/refs.c
+++ b/refs.c
@@ -907,7 +907,6 @@ static void copy_reflog_msg(struct strbuf *sb, const char *msg)
 	char c;
 	int wasspace = 1;
 
-	strbuf_addch(sb, '\t');
 	while ((c = *msg++)) {
 		if (wasspace && isspace(c))
 			continue;
diff --git a/refs/files-backend.c b/refs/files-backend.c
index e0aba23eb2..985631f33e 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1628,8 +1628,10 @@ static int log_ref_write_fd(int fd, const struct object_id *old_oid,
 	int ret = 0;
 
 	strbuf_addf(&sb, "%s %s %s", oid_to_hex(old_oid), oid_to_hex(new_oid), committer);
-	if (msg && *msg)
+	if (msg && *msg) {
+		strbuf_addch(&sb, '\t');
 		strbuf_addstr(&sb, msg);
+	}
 	strbuf_addch(&sb, '\n');
 	if (write_in_full(fd, sb.buf, sb.len) < 0)
 		ret = -1;

base-commit: e8ab941b671da6890181aea5b5755d1d9eea24ec
-- 
gitgitgadget