sequencer: treat REVERT_HEAD as a pseudo ref

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

path.c

@@ -1528,7 +1528,6 @@ char *xdg_cache_home(const char *filename)
 	return NULL;
 }
 
-REPO_GIT_PATH_FUNC(revert_head, "REVERT_HEAD")
 REPO_GIT_PATH_FUNC(squash_msg, "SQUASH_MSG")
 REPO_GIT_PATH_FUNC(merge_msg, "MERGE_MSG")
 REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR")

path.h

@@ -170,7 +170,6 @@ void report_linked_checkout_garbage(void);
 	}
 
 struct path_cache {
-	const char *revert_head;
 	const char *squash_msg;
 	const char *merge_msg;
 	const char *merge_rr;
@@ -181,12 +180,11 @@ struct path_cache {
 	const char *shallow;
 };
 
-#define PATH_CACHE_INIT                                              \
-	{                                                            \
-		NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL \
+#define PATH_CACHE_INIT                                        \
+	{                                                      \
+		NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL \
 	}
 
-const char *git_path_revert_head(struct repository *r);
 const char *git_path_squash_msg(struct repository *r);
 const char *git_path_merge_msg(struct repository *r);
 const char *git_path_merge_rr(struct repository *r);

sequencer.c

@@ -2317,8 +2317,10 @@ void sequencer_post_commit_cleanup(struct repository *r, int verbose)
 		need_cleanup = 1;
 	}
 
-	if (file_exists(git_path_revert_head(r))) {
-		if (!unlink(git_path_revert_head(r)) && verbose)
+	if (refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD")) {
+		if (!refs_delete_ref(get_main_ref_store(r), "", "REVERT_HEAD",
+				     NULL, 0) &&
+		    verbose)
 			warning(_("cancelling a revert in progress"));
 		opts.action = REPLAY_REVERT;
 		need_cleanup = 1;
@@ -2677,7 +2679,7 @@ static int create_seq_dir(struct repository *r)
 	const char *in_progress_error = NULL;
 	const char *in_progress_advice = NULL;
 	unsigned int advise_skip =
-		file_exists(git_path_revert_head(r)) ||
+		refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD") ||
 		refs_ref_exists(get_main_ref_store(r), "CHERRY_PICK_HEAD");
 
 	if (!sequencer_get_last_command(r, &action)) {
@@ -2778,7 +2780,7 @@ static int rollback_single_pick(struct repository *r)
 	struct object_id head_oid;
 
 	if (!refs_ref_exists(get_main_ref_store(r), "CHERRY_PICK_HEAD") &&
-	    !file_exists(git_path_revert_head(r)))
+	    !refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD"))
 		return error(_("no cherry-pick or revert in progress"));
 	if (read_ref_full("HEAD", 0, &head_oid, NULL))
 		return error(_("cannot resolve HEAD"));
@@ -2872,7 +2874,7 @@ int sequencer_skip(struct repository *r, struct replay_opts *opts)
 	 */
 	switch (opts->action) {
 	case REPLAY_REVERT:
-		if (!file_exists(git_path_revert_head(r))) {
+		if (!refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD")) {
 			if (action != REPLAY_REVERT)
 				return error(_("no revert in progress"));
 			if (!rollback_is_safe())
@@ -4210,7 +4212,7 @@ static int continue_single_pick(struct repository *r)
 	const char *argv[] = { "commit", NULL };
 
 	if (!refs_ref_exists(get_main_ref_store(r), "CHERRY_PICK_HEAD") &&
-	    !file_exists(git_path_revert_head(r)))
+	    !refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD"))
 		return error(_("no cherry-pick or revert in progress"));
 	return run_command_v_opt(argv, RUN_GIT_CMD);
 }
@@ -4390,7 +4392,7 @@ int sequencer_continue(struct repository *r, struct replay_opts *opts)
 		/* Verify that the conflict has been resolved */
 		if (refs_ref_exists(get_main_ref_store(r),
 				    "CHERRY_PICK_HEAD") ||
-		    file_exists(git_path_revert_head(r))) {
+		    refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD")) {
 			res = continue_single_pick(r);
 			if (res)
 				goto release_todo_list;

wt-status.c

@@ -1678,7 +1678,7 @@ void wt_status_get_state(struct repository *r,
 		oidcpy(&state->cherry_pick_head_oid, &oid);
 	}
 	wt_status_check_bisect(NULL, state);
-	if (!stat(git_path_revert_head(r), &st) &&
+	if (refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD") &&
 	    !get_oid("REVERT_HEAD", &oid)) {
 		state->revert_in_progress = 1;
 		oidcpy(&state->revert_head_oid, &oid);