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[PATCH 2/2] reflog: ignore expire-unreachable for "HEAD" reflog

From
Junio C Hamano <gitster@pobox.com>
Date
Apr 14, 2010, 20:35 UTC
Message-ID
<7vfx2xpyam.fsf@alter.siamese.dyndns.org>
In-Reply-To
<7vljcppycc.fsf@alter.siamese.dyndns.org>

"git reflog expire" (and "git gc") examines the reflog entries and discards old/stale ones using two criteria. The entries that are older than "reflogexpire" (defaults to 90 days) are unconditionally removed, and the entries that are older than "reflogexpireunreachable" (defaults to 30 days) are removed if the entry point at commits that are not reachable from the value of the ref.

This is reasonable for local branches, remote tracking branches and tags. You (or other people) may have failed experiments that have been made and then later discarded by resetting the tip of the branch back, and setting the value of "reflogexpireunreachable" shorter than that of "reflogexpire" will prune the entries that describe these failed experiments earlier than the entries that describe the steps that led to the current history.

It however doesn't make much sense for "HEAD" reflog. When you switch between branches, it is normal that the tip of the branch you were on is not an ancestor of the branch you have switched to. Expiring the entries that describe what you did while on the previous branch earlier than usual does not help.

The test t7701 relied on this incorrect behaviour of entries being pruned from the "HEAD" reflog. Work it around by setting the "HEAD" reflog entries to be expired immediately.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin-reflog.c                     |   35 ++++++++++++++++++++++++---------
 t/t7701-repack-unpack-unreachable.sh |    1 +
 2 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/builtin-reflog.c b/builtin-reflog.c
index 9792090..c4bc5be 100644
--- a/builtin-reflog.c
+++ b/builtin-reflog.c
@@ -34,8 +34,11 @@ struct cmd_reflog_expire_cb {
 
 struct expire_reflog_cb {
 	FILE *newlog;
-	const char *ref;
-	struct commit *ref_commit;
+	enum {
+		UE_NORMAL,
+		UE_ALWAYS,
+		UE_NEVER
+	} unreachable_expire_kind;
 	struct commit_list *mark_list;
 	unsigned long mark_limit;
 	struct cmd_reflog_expire_cb *cmd;
@@ -304,8 +307,9 @@ static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 	    (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
 		goto prune;
 
-	if (timestamp < cb->cmd->expire_unreachable) {
-		if (!cb->ref_commit)
+	if ((cb->unreachable_expire_kind != UE_NEVER) &&
+	    (timestamp < cb->cmd->expire_unreachable)) {
+		if (cb->unreachable_expire_kind == UE_ALWAYS)
 			goto prune;
 		if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
 			goto prune;
@@ -338,6 +342,7 @@ static int expire_reflog(const char *ref, const unsigned char *sha1, int unused,
 	struct expire_reflog_cb cb;
 	struct ref_lock *lock;
 	char *log_file, *newlog_path = NULL;
+	struct commit *tip_commit;
 	int status = 0;
 
 	memset(&cb, 0, sizeof(cb));
@@ -357,18 +362,28 @@ static int expire_reflog(const char *ref, const unsigned char *sha1, int unused,
 		cb.newlog = fopen(newlog_path, "w");
 	}
 
-	cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
-	cb.ref = ref;
 	cb.cmd = cmd;
-	if (cb.ref_commit) {
+
+	if (!cmd->expire_unreachable || !strcmp(ref, "HEAD")) {
+		tip_commit = NULL;
+		cb.unreachable_expire_kind = UE_NEVER;
+	} else {
+		tip_commit = lookup_commit_reference_gently(sha1, 1);
+		if (!tip_commit)
+			cb.unreachable_expire_kind = UE_ALWAYS;
+		else
+			cb.unreachable_expire_kind = UE_NORMAL;
+	}
+
+	if (cb.unreachable_expire_kind == UE_NORMAL) {
 		cb.mark_list = NULL;
-		commit_list_insert(cb.ref_commit, &cb.mark_list);
+		commit_list_insert(tip_commit, &cb.mark_list);
 		cb.mark_limit = cmd->expire_total;
 		mark_reachable(&cb);
 	}
 	for_each_reflog_ent(ref, expire_reflog_ent, &cb);
-	if (cb.ref_commit)
-		clear_commit_marks(cb.ref_commit, REACHABLE);
+	if (cb.unreachable_expire_kind == UE_NORMAL)
+		clear_commit_marks(tip_commit, REACHABLE);
  finish:
 	if (cb.newlog) {
 		if (fclose(cb.newlog)) {
diff --git a/t/t7701-repack-unpack-unreachable.sh b/t/t7701-repack-unpack-unreachable.sh
index 5babdf2..e14b110 100755
--- a/t/t7701-repack-unpack-unreachable.sh
+++ b/t/t7701-repack-unpack-unreachable.sh
@@ -9,6 +9,7 @@ csha1=
 tsha1=
 
 test_expect_success '-A with -d option leaves unreachable objects unpacked' '
+	git config gc.HEAD.reflogexpire now &&
 	echo content > file1 &&
 	git add . &&
 	git commit -m initial_commit &&
-- 
1.7.1.rc1.252.gce30c
Previous: Junio C HamanoNext: Johannes Sixt
Message 2 of 16 in “Document gc.<pattern>.reflogexpire variables”
  1. 1/2 Document gc.<pattern>.reflogexpire variablesJunio C Hamano, Apr 14, 2010
  2. 2/2 reflog: ignore expire-unreachable for "HEAD" reflogJunio C Hamano, Apr 14, 2010
  3. Johannes SixtApr 15, 2010
  4. Junio C HamanoApr 15, 2010
  5. Johannes SixtApr 15, 2010
  6. Junio C HamanoApr 15, 2010
  7. Johannes SixtApr 15, 2010
  8. Jeff KingApr 15, 2010
  9. Junio C HamanoApr 15, 2010
  10. Nicolas PitreApr 15, 2010
  11. Junio C HamanoApr 15, 2010
  12. Nicolas PitreApr 16, 2010
  13. Junio C HamanoApr 16, 2010
  14. Nicolas PitreApr 16, 2010
  15. Johannes SixtApr 16, 2010
  16. Junio C HamanoApr 15, 2010

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