advice: don't pointlessly suggest --convert-graft-file
[gitweb.git] / builtin / merge.c
index fbbf2a9e5eb9be47d8574ca0bab175c5a6c0d15d..8f4a5065c209b5b50e02271b48277fff90306338 100644 (file)
@@ -14,6 +14,7 @@
 #include "run-command.h"
 #include "diff.h"
 #include "refs.h"
+#include "refspec.h"
 #include "commit.h"
 #include "diffcore.h"
 #include "revision.h"
@@ -33,6 +34,8 @@
 #include "sequencer.h"
 #include "string-list.h"
 #include "packfile.h"
+#include "tag.h"
+#include "alias.h"
 
 #define DEFAULT_TWOHEAD (1<<0)
 #define DEFAULT_OCTOPUS (1<<1)
@@ -108,6 +111,35 @@ static int option_parse_message(const struct option *opt,
        return 0;
 }
 
+static int option_read_message(struct parse_opt_ctx_t *ctx,
+                              const struct option *opt, int unset)
+{
+       struct strbuf *buf = opt->value;
+       const char *arg;
+
+       if (unset)
+               BUG("-F cannot be negated");
+
+       if (ctx->opt) {
+               arg = ctx->opt;
+               ctx->opt = NULL;
+       } else if (ctx->argc > 1) {
+               ctx->argc--;
+               arg = *++ctx->argv;
+       } else
+               return opterror(opt, "requires a value", 0);
+
+       if (buf->len)
+               strbuf_addch(buf, '\n');
+       if (ctx->prefix && !is_absolute_path(arg))
+               arg = prefix_filename(ctx->prefix, arg);
+       if (strbuf_read_file(buf, arg, 0) < 0)
+               return error(_("could not read file '%s'"), arg);
+       have_message = 1;
+
+       return 0;
+}
+
 static struct strategy *get_strategy(const char *name)
 {
        int i;
@@ -212,9 +244,9 @@ static struct option builtin_merge_options[] = {
        OPT_BOOL('e', "edit", &option_edit,
                N_("edit message before committing")),
        OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
-       { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
-               N_("abort if fast-forward is not possible"),
-               PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
+       OPT_SET_INT_F(0, "ff-only", &fast_forward,
+                     N_("abort if fast-forward is not possible"),
+                     FF_ONLY, PARSE_OPT_NONEG),
        OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
        OPT_BOOL(0, "verify-signatures", &verify_signatures,
                N_("verify that the named commit has a valid GPG signature")),
@@ -225,6 +257,9 @@ static struct option builtin_merge_options[] = {
        OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
                N_("merge commit message (for a non-fast-forward merge)"),
                option_parse_message),
+       { OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
+               N_("read message from file"), PARSE_OPT_NONEG,
+               (parse_opt_cb *) option_read_message },
        OPT__VERBOSITY(&verbosity),
        OPT_BOOL(0, "abort", &abort_current_merge,
                N_("abort the current in-progress merge")),
@@ -244,9 +279,9 @@ static struct option builtin_merge_options[] = {
 /* Cleans up metadata that is uninteresting after a succeeded merge. */
 static void drop_save(void)
 {
-       unlink(git_path_merge_head());
-       unlink(git_path_merge_msg());
-       unlink(git_path_merge_mode());
+       unlink(git_path_merge_head(the_repository));
+       unlink(git_path_merge_msg(the_repository));
+       unlink(git_path_merge_mode(the_repository));
 }
 
 static int save_state(struct object_id *stash)
@@ -279,7 +314,7 @@ static int save_state(struct object_id *stash)
        return rc;
 }
 
-static void read_empty(unsigned const char *sha1, int verbose)
+static void read_empty(const struct object_id *oid, int verbose)
 {
        int i = 0;
        const char *args[7];
@@ -289,15 +324,15 @@ static void read_empty(unsigned const char *sha1, int verbose)
                args[i++] = "-v";
        args[i++] = "-m";
        args[i++] = "-u";
-       args[i++] = EMPTY_TREE_SHA1_HEX;
-       args[i++] = sha1_to_hex(sha1);
+       args[i++] = empty_tree_oid_hex();
+       args[i++] = oid_to_hex(oid);
        args[i] = NULL;
 
        if (run_command_v_opt(args, RUN_GIT_CMD))
                die(_("read-tree failed"));
 }
 
-static void reset_hard(unsigned const char *sha1, int verbose)
+static void reset_hard(const struct object_id *oid, int verbose)
 {
        int i = 0;
        const char *args[6];
@@ -307,7 +342,7 @@ static void reset_hard(unsigned const char *sha1, int verbose)
                args[i++] = "-v";
        args[i++] = "--reset";
        args[i++] = "-u";
-       args[i++] = sha1_to_hex(sha1);
+       args[i++] = oid_to_hex(oid);
        args[i] = NULL;
 
        if (run_command_v_opt(args, RUN_GIT_CMD))
@@ -323,7 +358,7 @@ static void restore_state(const struct object_id *head,
        if (is_null_oid(stash))
                return;
 
-       reset_hard(head->hash, 1);
+       reset_hard(head, 1);
 
        args[2] = oid_to_hex(stash);
 
@@ -379,7 +414,7 @@ static void squash_message(struct commit *commit, struct commit_list *remotehead
                        oid_to_hex(&commit->object.oid));
                pretty_print_commit(&ctx, commit, &out);
        }
-       write_file_buf(git_path_squash_msg(), out.buf, out.len);
+       write_file_buf(git_path_squash_msg(the_repository), out.buf, out.len);
        strbuf_release(&out);
 }
 
@@ -405,14 +440,13 @@ static void finish(struct commit *head_commit,
                        printf(_("No merge message -- not updating HEAD\n"));
                else {
                        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
-                       update_ref(reflog_message.buf, "HEAD",
-                               new_head->hash, head->hash, 0,
-                               UPDATE_REFS_DIE_ON_ERR);
+                       update_ref(reflog_message.buf, "HEAD", new_head, head,
+                                  0, UPDATE_REFS_DIE_ON_ERR);
                        /*
                         * We ignore errors in 'gc --auto', since the
                         * user should see them.
                         */
-                       close_all_packs();
+                       close_all_packs(the_repository->objects);
                        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
                }
        }
@@ -443,6 +477,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
        struct object_id branch_head;
        struct strbuf buf = STRBUF_INIT;
        struct strbuf bname = STRBUF_INIT;
+       struct merge_remote_desc *desc;
        const char *ptr;
        char *found_ref;
        int len, early;
@@ -455,7 +490,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
        if (!remote_head)
                die(_("'%s' does not point to a commit"), remote);
 
-       if (dwim_ref(remote, strlen(remote), branch_head.hash, &found_ref) > 0) {
+       if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
                if (starts_with(found_ref, "refs/heads/")) {
                        strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
                                    oid_to_hex(&branch_head), remote);
@@ -515,16 +550,13 @@ static void merge_name(const char *remote, struct strbuf *msg)
                strbuf_release(&truname);
        }
 
-       if (remote_head->util) {
-               struct merge_remote_desc *desc;
-               desc = merge_remote_util(remote_head);
-               if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
-                       strbuf_addf(msg, "%s\t\t%s '%s'\n",
-                                   oid_to_hex(&desc->obj->oid),
-                                   typename(desc->obj->type),
-                                   remote);
-                       goto cleanup;
-               }
+       desc = merge_remote_util(remote_head);
+       if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
+               strbuf_addf(msg, "%s\t\t%s '%s'\n",
+                           oid_to_hex(&desc->obj->oid),
+                           type_name(desc->obj->type),
+                           remote);
+               goto cleanup;
        }
 
        strbuf_addf(msg, "%s\t\tcommit '%s'\n",
@@ -568,6 +600,8 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 
        if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
                show_diffstat = git_config_bool(k, v);
+       else if (!strcmp(k, "merge.verifysignatures"))
+               verify_signatures = git_config_bool(k, v);
        else if (!strcmp(k, "pull.twohead"))
                return git_config_string(&pull_twohead, k, v);
        else if (!strcmp(k, "pull.octopus"))
@@ -637,7 +671,7 @@ static int read_tree_trivial(struct object_id *common, struct object_id *head,
 
 static void write_tree_trivial(struct object_id *oid)
 {
-       if (write_cache_as_tree(oid->hash, 0, NULL))
+       if (write_cache_as_tree(oid, 0, NULL))
                die(_("git write-tree failed to write a tree"));
 }
 
@@ -645,15 +679,14 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
                              struct commit_list *remoteheads,
                              struct commit *head)
 {
-       static struct lock_file lock;
+       struct lock_file lock = LOCK_INIT;
        const char *head_arg = "HEAD";
 
        hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
        refresh_cache(REFRESH_QUIET);
-       if (active_cache_changed &&
-           write_locked_index(&the_index, &lock, COMMIT_LOCK))
+       if (write_locked_index(&the_index, &lock,
+                              COMMIT_LOCK | SKIP_IF_UNCHANGED))
                return error(_("Unable to write index."));
-       rollback_lock_file(&lock);
 
        if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
                int clean, x;
@@ -690,10 +723,9 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
                                remoteheads->item, reversed, &result);
                if (clean < 0)
                        exit(128);
-               if (active_cache_changed &&
-                   write_locked_index(&the_index, &lock, COMMIT_LOCK))
-                       die (_("unable to write %s"), get_index_file());
-               rollback_lock_file(&lock);
+               if (write_locked_index(&the_index, &lock,
+                                      COMMIT_LOCK | SKIP_IF_UNCHANGED))
+                       die(_("unable to write %s"), get_index_file());
                return clean ? 0 : 1;
        } else {
                return try_merge_command(strategy, xopts_nr, xopts,
@@ -741,7 +773,7 @@ static void add_strategies(const char *string, unsigned attr)
 
 static void read_merge_msg(struct strbuf *msg)
 {
-       const char *filename = git_path_merge_msg();
+       const char *filename = git_path_merge_msg(the_repository);
        strbuf_reset(msg);
        if (strbuf_read_file(msg, filename, 0) < 0)
                die_errno(_("Could not read from '%s'"), filename);
@@ -778,18 +810,18 @@ static void prepare_to_commit(struct commit_list *remoteheads)
        if (signoff)
                append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
        write_merge_heads(remoteheads);
-       write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
+       write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
        if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
-                           git_path_merge_msg(), "merge", NULL))
+                           git_path_merge_msg(the_repository), "merge", NULL))
                abort_commit(remoteheads, NULL);
        if (0 < option_edit) {
-               if (launch_editor(git_path_merge_msg(), NULL, NULL))
+               if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
                        abort_commit(remoteheads, NULL);
        }
 
        if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
                                          "commit-msg",
-                                         git_path_merge_msg(), NULL))
+                                         git_path_merge_msg(the_repository), NULL))
                abort_commit(remoteheads, NULL);
 
        read_merge_msg(&msg);
@@ -805,22 +837,21 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 {
        struct object_id result_tree, result_commit;
        struct commit_list *parents, **pptr = &parents;
-       static struct lock_file lock;
+       struct lock_file lock = LOCK_INIT;
 
        hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
        refresh_cache(REFRESH_QUIET);
-       if (active_cache_changed &&
-           write_locked_index(&the_index, &lock, COMMIT_LOCK))
+       if (write_locked_index(&the_index, &lock,
+                              COMMIT_LOCK | SKIP_IF_UNCHANGED))
                return error(_("Unable to write index."));
-       rollback_lock_file(&lock);
 
        write_tree_trivial(&result_tree);
        printf(_("Wonderful.\n"));
        pptr = commit_list_append(head, pptr);
        pptr = commit_list_append(remoteheads->item, pptr);
        prepare_to_commit(remoteheads);
-       if (commit_tree(merge_msg.buf, merge_msg.len, result_tree.hash, parents,
-                       result_commit.hash, NULL, sign_commit))
+       if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
+                       &result_commit, NULL, sign_commit))
                die(_("failed to write commit object"));
        finish(head, remoteheads, &result_commit, "In-index merge");
        drop_save();
@@ -844,8 +875,8 @@ static int finish_automerge(struct commit *head,
                commit_list_insert(head, &parents);
        strbuf_addch(&merge_msg, '\n');
        prepare_to_commit(remoteheads);
-       if (commit_tree(merge_msg.buf, merge_msg.len, result_tree->hash, parents,
-                       result_commit.hash, NULL, sign_commit))
+       if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
+                       &result_commit, NULL, sign_commit))
                die(_("failed to write commit object"));
        strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
        finish(head, remoteheads, &result_commit, buf.buf);
@@ -860,7 +891,7 @@ static int suggest_conflicts(void)
        FILE *fp;
        struct strbuf msgbuf = STRBUF_INIT;
 
-       filename = git_path_merge_msg();
+       filename = git_path_merge_msg(the_repository);
        fp = xfopen(filename, "a");
 
        append_conflicts_hint(&msgbuf);
@@ -933,19 +964,22 @@ static void write_merge_heads(struct commit_list *remoteheads)
        for (j = remoteheads; j; j = j->next) {
                struct object_id *oid;
                struct commit *c = j->item;
-               if (c->util && merge_remote_util(c)->obj) {
-                       oid = &merge_remote_util(c)->obj->oid;
+               struct merge_remote_desc *desc;
+
+               desc = merge_remote_util(c);
+               if (desc && desc->obj) {
+                       oid = &desc->obj->oid;
                } else {
                        oid = &c->object.oid;
                }
                strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
        }
-       write_file_buf(git_path_merge_head(), buf.buf, buf.len);
+       write_file_buf(git_path_merge_head(the_repository), buf.buf, buf.len);
 
        strbuf_reset(&buf);
        if (fast_forward == FF_NO)
                strbuf_addstr(&buf, "no-ff");
-       write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
+       write_file_buf(git_path_merge_mode(the_repository), buf.buf, buf.len);
        strbuf_release(&buf);
 }
 
@@ -953,7 +987,8 @@ static void write_merge_state(struct commit_list *remoteheads)
 {
        write_merge_heads(remoteheads);
        strbuf_addch(&merge_msg, '\n');
-       write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
+       write_file_buf(git_path_merge_msg(the_repository), merge_msg.buf,
+                      merge_msg.len);
 }
 
 static int default_edit_option(void)
@@ -1032,11 +1067,12 @@ static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge
        const char *filename;
        int fd, pos, npos;
        struct strbuf fetch_head_file = STRBUF_INIT;
+       const unsigned hexsz = the_hash_algo->hexsz;
 
        if (!merge_names)
                merge_names = &fetch_head_file;
 
-       filename = git_path_fetch_head();
+       filename = git_path_fetch_head(the_repository);
        fd = open(filename, O_RDONLY);
        if (fd < 0)
                die_errno(_("could not open '%s' for reading"), filename);
@@ -1057,16 +1093,16 @@ static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge
                else
                        npos = merge_names->len;
 
-               if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
+               if (npos - pos < hexsz + 2 ||
                    get_oid_hex(merge_names->buf + pos, &oid))
                        commit = NULL; /* bad */
-               else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
+               else if (memcmp(merge_names->buf + pos + hexsz, "\t\t", 2))
                        continue; /* not-for-merge */
                else {
-                       char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
-                       merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
+                       char saved = merge_names->buf[pos + hexsz];
+                       merge_names->buf[pos + hexsz] = '\0';
                        commit = get_merge_parent(merge_names->buf + pos);
-                       merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
+                       merge_names->buf[pos + hexsz] = saved;
                }
                if (!commit) {
                        if (ptr)
@@ -1124,6 +1160,43 @@ static struct commit_list *collect_parents(struct commit *head_commit,
        return remoteheads;
 }
 
+static int merging_a_throwaway_tag(struct commit *commit)
+{
+       char *tag_ref;
+       struct object_id oid;
+       int is_throwaway_tag = 0;
+
+       /* Are we merging a tag? */
+       if (!merge_remote_util(commit) ||
+           !merge_remote_util(commit)->obj ||
+           merge_remote_util(commit)->obj->type != OBJ_TAG)
+               return is_throwaway_tag;
+
+       /*
+        * Now we know we are merging a tag object.  Are we downstream
+        * and following the tags from upstream?  If so, we must have
+        * the tag object pointed at by "refs/tags/$T" where $T is the
+        * tagname recorded in the tag object.  We want to allow such
+        * a "just to catch up" merge to fast-forward.
+        *
+        * Otherwise, we are playing an integrator's role, making a
+        * merge with a throw-away tag from a contributor with
+        * something like "git pull $contributor $signed_tag".
+        * We want to forbid such a merge from fast-forwarding
+        * by default; otherwise we would not keep the signature
+        * anywhere.
+        */
+       tag_ref = xstrfmt("refs/tags/%s",
+                         ((struct tag *)merge_remote_util(commit)->obj)->tag);
+       if (!read_ref(tag_ref, &oid) &&
+           !oidcmp(&oid, &merge_remote_util(commit)->obj->oid))
+               is_throwaway_tag = 0;
+       else
+               is_throwaway_tag = 1;
+       free(tag_ref);
+       return is_throwaway_tag;
+}
+
 int cmd_merge(int argc, const char **argv, const char *prefix)
 {
        struct object_id result_tree, stash, head_oid;
@@ -1144,17 +1217,18 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
         * Check if we are _not_ on a detached HEAD, i.e. if there is a
         * current branch.
         */
-       branch = branch_to_free = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
+       branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
        if (branch)
                skip_prefix(branch, "refs/heads/", &branch);
+
+       init_diff_ui_defaults();
+       git_config(git_merge_config, NULL);
+
        if (!branch || is_null_oid(&head_oid))
                head_commit = NULL;
        else
                head_commit = lookup_commit_or_die(&head_oid, "HEAD");
 
-       init_diff_ui_defaults();
-       git_config(git_merge_config, NULL);
-
        if (branch_mergeoptions)
                parse_branch_merge_options(branch_mergeoptions);
        argc = parse_options(argc, argv, prefix, builtin_merge_options,
@@ -1173,7 +1247,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                        usage_msg_opt(_("--abort expects no arguments"),
                              builtin_merge_usage, builtin_merge_options);
 
-               if (!file_exists(git_path_merge_head()))
+               if (!file_exists(git_path_merge_head(the_repository)))
                        die(_("There is no merge to abort (MERGE_HEAD missing)."));
 
                /* Invoke 'git reset --merge' */
@@ -1189,7 +1263,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                        usage_msg_opt(_("--continue expects no arguments"),
                              builtin_merge_usage, builtin_merge_options);
 
-               if (!file_exists(git_path_merge_head()))
+               if (!file_exists(git_path_merge_head(the_repository)))
                        die(_("There is no merge in progress (MERGE_HEAD missing)."));
 
                /* Invoke 'git commit' */
@@ -1200,7 +1274,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
        if (read_cache_unmerged())
                die_resolve_conflict("merge");
 
-       if (file_exists(git_path_merge_head())) {
+       if (file_exists(git_path_merge_head(the_repository))) {
                /*
                 * There is no unmerged entry, don't advise 'git
                 * add/rm <file>', just 'git commit'.
@@ -1211,7 +1285,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                else
                        die(_("You have not concluded your merge (MERGE_HEAD exists)."));
        }
-       if (file_exists(git_path_cherry_pick_head())) {
+       if (file_exists(git_path_cherry_pick_head(the_repository))) {
                if (advice_resolve_conflict)
                        die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
                            "Please, commit your changes before you merge."));
@@ -1261,9 +1335,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                if (remoteheads->next)
                        die(_("Can merge only exactly one commit into empty head"));
                remote_head_oid = &remoteheads->item->object.oid;
-               read_empty(remote_head_oid->hash, 0);
-               update_ref("initial pull", "HEAD", remote_head_oid->hash,
-                          NULL, 0, UPDATE_REFS_DIE_ON_ERR);
+               read_empty(remote_head_oid, 0);
+               update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
+                          UPDATE_REFS_DIE_ON_ERR);
                goto done;
        }
 
@@ -1288,7 +1362,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 
                        check_commit_signature(commit, &signature_check);
 
-                       find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
+                       find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
                        switch (signature_check.result) {
                        case 'G':
                                break;
@@ -1321,10 +1395,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                            oid_to_hex(&commit->object.oid));
                setenv(buf.buf, merge_remote_util(commit)->name, 1);
                strbuf_reset(&buf);
-               if (fast_forward != FF_ONLY &&
-                   merge_remote_util(commit) &&
-                   merge_remote_util(commit)->obj &&
-                   merge_remote_util(commit)->obj->type == OBJ_TAG)
+               if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
                        fast_forward = FF_NO;
        }
 
@@ -1358,8 +1429,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                free(list);
        }
 
-       update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.oid.hash,
-                  NULL, 0, UPDATE_REFS_DIE_ON_ERR);
+       update_ref("updating ORIG_HEAD", "ORIG_HEAD",
+                  &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 
        if (remoteheads && !common) {
                /* No common ancestors found. */
@@ -1384,9 +1455,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 
                if (verbosity >= 0) {
                        printf(_("Updating %s..%s\n"),
-                              find_unique_abbrev(head_commit->object.oid.hash,
+                              find_unique_abbrev(&head_commit->object.oid,
                                                  DEFAULT_ABBREV),
-                              find_unique_abbrev(remoteheads->item->object.oid.hash,
+                              find_unique_abbrev(&remoteheads->item->object.oid,
                                                  DEFAULT_ABBREV));
                }
                strbuf_addstr(&msg, "Fast-forward");