[PATCH 4/4] RFC: refs: reflog entries aren't written based on reflog existence.

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

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

Before, if we aren't supposed to update reflogs (eg.
core.logallrefupdates=NONE), we would still write reflog entries if the
reflog file (.git/logs/REFNAME) existed.

The reftable storage backend cannot distinguish between a non-existing
reflog, and an empty one. Therefore it cannot mimick this functionality.

In CAFQ2z_Ps3YxycA+NJ9VKt_PEXb+m83JdNB7ujzWw1fTPKyZ=fg@mail.gmail.com,
we came to the conclusion that this feature is probably a remnant from
the time that reflogs weren't enabled by default, and it does not need
to be kept.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
---
 refs/files-backend.c  | 20 +-------------------
 t/t1400-update-ref.sh |  7 +++----
 2 files changed, 4 insertions(+), 23 deletions(-)

diff --git a/refs/files-backend.c b/refs/files-backend.c
index e05ada9286d..25f5a4ce777 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1551,6 +1551,7 @@ static int log_ref_setup(struct files_ref_store *refs,
 	struct strbuf logfile_sb = STRBUF_INIT;
 	char *logfile;
 
+	*logfd = -1;
 	files_reflog_path(refs, &logfile_sb, refname);
 	logfile = strbuf_detach(&logfile_sb, NULL);
 
@@ -1565,26 +1566,8 @@ static int log_ref_setup(struct files_ref_store *refs,
 			else
 				strbuf_addf(err, "unable to append to '%s': %s",
 					    logfile, strerror(errno));
-
 			goto error;
 		}
-	} else {
-		*logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
-		if (*logfd < 0) {
-			if (errno == ENOENT || errno == EISDIR) {
-				/*
-				 * The logfile doesn't already exist,
-				 * but that is not an error; it only
-				 * means that we won't write log
-				 * entries to it.
-				 */
-				;
-			} else {
-				strbuf_addf(err, "unable to append to '%s': %s",
-					    logfile, strerror(errno));
-				goto error;
-			}
-		}
 	}
 
 	if (*logfd >= 0)
@@ -1592,7 +1575,6 @@ static int log_ref_setup(struct files_ref_store *refs,
 
 	free(logfile);
 	return 0;
-
 error:
 	free(logfile);
 	return -1;
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index de0cf678f8e..52433f6d0d2 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -269,7 +269,7 @@ test_expect_success "(not) changed .git/$m" '
 '
 
 rm -f .git/logs/refs/heads/main
-test_expect_success "create $m (logged by touch)" '
+test_expect_success "create $m" '
 	test_config core.logAllRefUpdates false &&
 	GIT_COMMITTER_DATE="2005-05-26 23:30" \
 	git update-ref --create-reflog HEAD $A -m "Initial Creation" &&
@@ -315,12 +315,10 @@ test_expect_success 'symref empty directory removal' '
 	test_path_is_file .git/logs/HEAD
 '
 
-TAB='	'
 cat >expect <<EOF
 $Z $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000	Initial Creation
-$A $B $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150260 +0000	Switch
-$B $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150860 +0000$TAB
 EOF
+
 test_expect_success "verifying $m's log (logged by touch)" '
 	test_when_finished "git update-ref -d $m && rm -rf .git/logs actual expect" &&
 	test-tool ref-store main for-each-reflog-ent $m > actual &&
@@ -346,6 +344,7 @@ test_expect_success "set $m (logged by config)" '
 	test $A = $(git show-ref -s --verify $m)
 '
 
+TAB='	'
 cat >expect <<EOF
 $Z $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150320 +0000	Initial Creation
 $A $B $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150380 +0000	Switch
-- 
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