[PATCH v3 8/8] reflog expire: cover reflog from all worktrees

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/git-reflog.txt |  7 +++++-
 builtin/reflog.c             | 46 ++++++++++++++++++++++++++++++++----
 t/t1410-reflog.sh            | 15 ++++++++++++
 3 files changed, 63 insertions(+), 5 deletions(-)

diff --git a/Documentation/git-reflog.txt b/Documentation/git-reflog.txt
index 472a6808cd..ff487ff77d 100644
--- a/Documentation/git-reflog.txt
+++ b/Documentation/git-reflog.txt
@@ -20,7 +20,7 @@ depending on the subcommand:
 'git reflog' ['show'] [log-options] [<ref>]
 'git reflog expire' [--expire=<time>] [--expire-unreachable=<time>]
 	[--rewrite] [--updateref] [--stale-fix]
-	[--dry-run | -n] [--verbose] [--all | <refs>...]
+	[--dry-run | -n] [--verbose] [--all [--single-worktree] | <refs>...]
 'git reflog delete' [--rewrite] [--updateref]
 	[--dry-run | -n] [--verbose] ref@\{specifier\}...
 'git reflog exists' <ref>
@@ -72,6 +72,11 @@ Options for `expire`
 --all::
 	Process the reflogs of all references.
 
+--single-worktree::
+	By default when `--all` is specified, reflogs from all working
+	trees are processed. This option limits the processing to reflogs
+	from the current working tree only.
+
 --expire=<time>::
 	Prune entries older than the specified time. If this option is
 	not specified, the expiration time is taken from the
diff --git a/builtin/reflog.c b/builtin/reflog.c
index b5941c1ff3..7a85e4b164 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -10,6 +10,7 @@
 #include "diff.h"
 #include "revision.h"
 #include "reachable.h"
+#include "worktree.h"
 
 /* NEEDSWORK: switch to using parse_options */
 static const char reflog_expire_usage[] =
@@ -52,6 +53,7 @@ struct collect_reflog_cb {
 	struct collected_reflog **e;
 	int alloc;
 	int nr;
+	struct worktree *wt;
 };
 
 /* Remember to update object flag allocation in object.h */
@@ -330,13 +332,27 @@ static int push_tip_to_list(const char *refname, const struct object_id *oid,
 	return 0;
 }
 
+static int is_head(const char *refname)
+{
+	switch (ref_type(refname)) {
+	case REF_TYPE_OTHER_PSEUDOREF:
+	case REF_TYPE_MAIN_PSEUDOREF:
+		if (parse_worktree_ref(refname, NULL, NULL, &refname))
+			BUG("not a worktree ref: %s", refname);
+		break;
+	default:
+		break;
+	}
+	return !strcmp(refname, "HEAD");
+}
+
 static void reflog_expiry_prepare(const char *refname,
 				  const struct object_id *oid,
 				  void *cb_data)
 {
 	struct expire_reflog_policy_cb *cb = cb_data;
 
-	if (!cb->cmd.expire_unreachable || !strcmp(refname, "HEAD")) {
+	if (!cb->cmd.expire_unreachable || is_head(refname)) {
 		cb->tip_commit = NULL;
 		cb->unreachable_expire_kind = UE_HEAD;
 	} else {
@@ -388,8 +404,19 @@ static int collect_reflog(const char *ref, const struct object_id *oid, int unus
 {
 	struct collected_reflog *e;
 	struct collect_reflog_cb *cb = cb_data;
+	struct strbuf newref = STRBUF_INIT;
+
+	/*
+	 * Avoid collecting the same shared ref multiple times because
+	 * they are available via all worktrees.
+	 */
+	if (!cb->wt->is_current && ref_type(ref) == REF_TYPE_NORMAL)
+		return 0;
+
+	strbuf_worktree_ref(cb->wt, &newref, ref);
+	FLEX_ALLOC_STR(e, reflog, newref.buf);
+	strbuf_release(&newref);
 
-	FLEX_ALLOC_STR(e, reflog, ref);
 	oidcpy(&e->oid, oid);
 	ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
 	cb->e[cb->nr++] = e;
@@ -512,7 +539,7 @@ static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 {
 	struct expire_reflog_policy_cb cb;
 	timestamp_t now = time(NULL);
-	int i, status, do_all;
+	int i, status, do_all, all_worktrees = 1;
 	int explicit_expiry = 0;
 	unsigned int flags = 0;
 
@@ -549,6 +576,8 @@ static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 			flags |= EXPIRE_REFLOGS_UPDATE_REF;
 		else if (!strcmp(arg, "--all"))
 			do_all = 1;
+		else if (!strcmp(arg, "--single-worktree"))
+			all_worktrees = 0;
 		else if (!strcmp(arg, "--verbose"))
 			flags |= EXPIRE_REFLOGS_VERBOSE;
 		else if (!strcmp(arg, "--")) {
@@ -577,10 +606,19 @@ static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
 
 	if (do_all) {
 		struct collect_reflog_cb collected;
+		struct worktree **worktrees, **p;
 		int i;
 
 		memset(&collected, 0, sizeof(collected));
-		for_each_reflog(collect_reflog, &collected);
+		worktrees = get_worktrees(0);
+		for (p = worktrees; *p; p++) {
+			if (!all_worktrees && !(*p)->is_current)
+				continue;
+			collected.wt = *p;
+			refs_for_each_reflog(get_worktree_ref_store(*p),
+					     collect_reflog, &collected);
+		}
+		free_worktrees(worktrees);
 		for (i = 0; i < collected.nr; i++) {
 			struct collected_reflog *e = collected.e[i];
 			set_reflog_expiry_param(&cb.cmd, explicit_expiry, e->reflog);
diff --git a/t/t1410-reflog.sh b/t/t1410-reflog.sh
index 388b0611d8..3e053532eb 100755
--- a/t/t1410-reflog.sh
+++ b/t/t1410-reflog.sh
@@ -368,4 +368,19 @@ test_expect_success 'continue walking past root commits' '
 	)
 '
 
+test_expect_success 'expire with multiple worktrees' '
+	git init main-wt &&
+	(
+		cd main-wt &&
+		test_tick &&
+		test_commit foo &&
+		git  worktree add link-wt &&
+		test_tick &&
+		test_commit -C link-wt foobar &&
+		test_tick &&
+		git reflog expire --verbose --all --expire=$test_tick &&
+		test_must_be_empty .git/worktrees/link-wt/logs/HEAD
+	)
+'
+
 test_done
-- 
2.19.1.647.g708186aaf9