sequencer: introduce functions to handle autostashes via refs

We're about to convert the MERGE_AUTOSTASH ref to become non-special,
using the refs API instead of direct filesystem access to both read and
write the ref. The current interfaces to write autostashes is entirely
path-based though, so we need to extend them to also support writes via
the refs API instead.

Ideally, we would be able to fully replace the old set of path-based
interfaces. But the sequencer will continue to write state into
"rebase-merge/autostash". This path is not considered to be a ref at all
and will thus stay is-is for now, which requires us to keep both path-
and refs-based interfaces to handle autostashes.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sequencer.c b/sequencer.c
index 47c8d17cbb93edc7e29b2795dfde12732b33b078..91de546b323e30022e0428628b594ac9174f2ae5 100644 (file)
--- a/sequencer.c
+++ b/sequencer.c
@@ -4463,12 +4463,17 @@ static enum todo_command peek_command(struct todo_list *todo_list, int offset)
        return -1;
 }
 
-void create_autostash(struct repository *r, const char *path)
+static void create_autostash_internal(struct repository *r,
+                                     const char *path,
+                                     const char *refname)
 {
        struct strbuf buf = STRBUF_INIT;
        struct lock_file lock_file = LOCK_INIT;
        int fd;
 
+       if (path && refname)
+               BUG("can only pass path or refname");
+
        fd = repo_hold_locked_index(r, &lock_file, 0);
        refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
        if (0 <= fd)
@@ -4495,10 +4500,16 @@ void create_autostash(struct repository *r, const char *path)
                strbuf_reset(&buf);
                strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
 
-               if (safe_create_leading_directories_const(path))
-                       die(_("Could not create directory for '%s'"),
-                           path);
-               write_file(path, "%s", oid_to_hex(&oid));
+               if (path) {
+                       if (safe_create_leading_directories_const(path))
+                               die(_("Could not create directory for '%s'"),
+                                   path);
+                       write_file(path, "%s", oid_to_hex(&oid));
+               } else {
+                       refs_update_ref(get_main_ref_store(r), "", refname,
+                                       &oid, null_oid(), 0, UPDATE_REFS_DIE_ON_ERR);
+               }
+
                printf(_("Created autostash: %s\n"), buf.buf);
                if (reset_head(r, &ropts) < 0)
                        die(_("could not reset --hard"));
@@ -4509,6 +4520,16 @@ void create_autostash(struct repository *r, const char *path)
        strbuf_release(&buf);
 }
 
+void create_autostash(struct repository *r, const char *path)
+{
+       create_autostash_internal(r, path, NULL);
+}
+
+void create_autostash_ref(struct repository *r, const char *refname)
+{
+       create_autostash_internal(r, NULL, refname);
+}
+
 static int apply_save_autostash_oid(const char *stash_oid, int attempt_apply)
 {
        struct child_process child = CHILD_PROCESS_INIT;
@@ -4586,6 +4607,41 @@ int apply_autostash_oid(const char *stash_oid)
        return apply_save_autostash_oid(stash_oid, 1);
 }
 
+static int apply_save_autostash_ref(struct repository *r, const char *refname,
+                                   int attempt_apply)
+{
+       struct object_id stash_oid;
+       char stash_oid_hex[GIT_MAX_HEXSZ + 1];
+       int flag, ret;
+
+       if (!refs_ref_exists(get_main_ref_store(r), refname))
+               return 0;
+
+       if (!refs_resolve_ref_unsafe(get_main_ref_store(r), refname,
+                                    RESOLVE_REF_READING, &stash_oid, &flag))
+               return -1;
+       if (flag & REF_ISSYMREF)
+               return error(_("autostash reference is a symref"));
+
+       oid_to_hex_r(stash_oid_hex, &stash_oid);
+       ret = apply_save_autostash_oid(stash_oid_hex, attempt_apply);
+
+       refs_delete_ref(get_main_ref_store(r), "", refname,
+                       &stash_oid, REF_NO_DEREF);
+
+       return ret;
+}
+
+int save_autostash_ref(struct repository *r, const char *refname)
+{
+       return apply_save_autostash_ref(r, refname, 0);
+}
+
+int apply_autostash_ref(struct repository *r, const char *refname)
+{
+       return apply_save_autostash_ref(r, refname, 1);
+}
+
 static int checkout_onto(struct repository *r, struct replay_opts *opts,
                         const char *onto_name, const struct object_id *onto,
                         const struct object_id *orig_head)

diff --git a/sequencer.h b/sequencer.h
index 913a0f652d9ab356bc066f162fa1e5197f6900eb..dcef7bb99c08b0f8e5a29905f8f3a4d6d2d34a45 100644 (file)
--- a/sequencer.h
+++ b/sequencer.h
@@ -225,9 +225,12 @@ void commit_post_rewrite(struct repository *r,
                         const struct object_id *new_head);
 
 void create_autostash(struct repository *r, const char *path);
+void create_autostash_ref(struct repository *r, const char *refname);
 int save_autostash(const char *path);
+int save_autostash_ref(struct repository *r, const char *refname);
 int apply_autostash(const char *path);
 int apply_autostash_oid(const char *stash_oid);
+int apply_autostash_ref(struct repository *r, const char *refname);
 
 #define SUMMARY_INITIAL_COMMIT   (1 << 0)
 #define SUMMARY_SHOW_AUTHOR_DATE (1 << 1)