1 files changed, 68 insertions, 52 deletions

diff --git a/builtin/merge.c b/builtin/merge.c
index 3ec97a8345..d82f6c19a3 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -64,6 +64,7 @@ static int option_renormalize;
 static int verbosity;
 static int allow_rerere_auto;
 static int abort_current_merge;
+static int allow_unrelated_histories;
 static int show_progress = -1;
 static int default_to_upstream = 1;
 static const char *sign_commit;
@@ -210,7 +211,7 @@ static struct option builtin_merge_options[] = {
 		PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
 	OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
 	OPT_BOOL(0, "verify-signatures", &verify_signatures,
-		N_("Verify that the named commit has a valid GPG signature")),
+		N_("verify that the named commit has a valid GPG signature")),
 	OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
 		N_("merge strategy to use"), option_parse_strategy),
 	OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
@@ -221,6 +222,8 @@ static struct option builtin_merge_options[] = {
 	OPT__VERBOSITY(&verbosity),
 	OPT_BOOL(0, "abort", &abort_current_merge,
 		N_("abort the current in-progress merge")),
+	OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
+		 N_("allow merging unrelated histories")),
 	OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
 	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
 	  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
@@ -365,7 +368,7 @@ static void squash_message(struct commit *commit, struct commit_list *remotehead
 	while ((commit = get_revision(&rev)) != NULL) {
 		strbuf_addch(&out, '\n');
 		strbuf_addf(&out, "commit %s\n",
-			sha1_to_hex(commit->object.sha1));
+			oid_to_hex(&commit->object.oid));
 		pretty_print_commit(&ctx, commit, &out);
 	}
 	if (write_in_full(fd, out.buf, out.len) != out.len)
@@ -380,7 +383,7 @@ static void finish(struct commit *head_commit,
 		   const unsigned char *new_head, const char *msg)
 {
 	struct strbuf reflog_message = STRBUF_INIT;
-	const unsigned char *head = head_commit->object.sha1;
+	const unsigned char *head = head_commit->object.oid.hash;
 
 	if (!msg)
 		strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
@@ -404,6 +407,7 @@ static void finish(struct commit *head_commit,
 			 * We ignore errors in 'gc --auto', since the
 			 * user should see them.
 			 */
+			close_all_packs();
 			run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 		}
 	}
@@ -497,7 +501,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
 		if (ref_exists(truname.buf)) {
 			strbuf_addf(msg,
 				    "%s\t\tbranch '%s'%s of .\n",
-				    sha1_to_hex(remote_head->object.sha1),
+				    sha1_to_hex(remote_head->object.oid.hash),
 				    truname.buf + 11,
 				    (early ? " (early part)" : ""));
 			strbuf_release(&truname);
@@ -511,7 +515,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
 		desc = merge_remote_util(remote_head);
 		if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
 			strbuf_addf(msg, "%s\t\t%s '%s'\n",
-				    sha1_to_hex(desc->obj->sha1),
+				    sha1_to_hex(desc->obj->oid.hash),
 				    typename(desc->obj->type),
 				    remote);
 			goto cleanup;
@@ -519,7 +523,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
 	}
 
 	strbuf_addf(msg, "%s\t\tcommit '%s'\n",
-		sha1_to_hex(remote_head->object.sha1), remote);
+		sha1_to_hex(remote_head->object.oid.hash), remote);
 cleanup:
 	strbuf_release(&buf);
 	strbuf_release(&bname);
@@ -818,6 +822,14 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 {
 	unsigned char result_tree[20], result_commit[20];
 	struct commit_list *parents, **pptr = &parents;
+	static struct lock_file lock;
+
+	hold_locked_index(&lock, 1);
+	refresh_cache(REFRESH_QUIET);
+	if (active_cache_changed &&
+	    write_locked_index(&the_index, &lock, COMMIT_LOCK))
+		return error(_("Unable to write index."));
+	rollback_lock_file(&lock);
 
 	write_tree_trivial(result_tree);
 	printf(_("Wonderful.\n"));
@@ -892,7 +904,7 @@ static struct commit *is_old_style_invocation(int argc, const char **argv,
 		second_token = lookup_commit_reference_gently(second_sha1, 0);
 		if (!second_token)
 			die(_("'%s' is not a commit"), argv[1]);
-		if (hashcmp(second_token->object.sha1, head))
+		if (hashcmp(second_token->object.oid.hash, head))
 			return NULL;
 	}
 	return second_token;
@@ -938,7 +950,7 @@ static int setup_with_upstream(const char ***argv)
 	if (!branch->merge_nr)
 		die(_("No default upstream defined for the current branch."));
 
-	args = xcalloc(branch->merge_nr + 1, sizeof(char *));
+	args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
 	for (i = 0; i < branch->merge_nr; i++) {
 		if (!branch->merge[i]->dst)
 			die(_("No remote-tracking branch for %s from %s"),
@@ -958,14 +970,14 @@ static void write_merge_state(struct commit_list *remoteheads)
 	struct strbuf buf = STRBUF_INIT;
 
 	for (j = remoteheads; j; j = j->next) {
-		unsigned const char *sha1;
+		struct object_id *oid;
 		struct commit *c = j->item;
 		if (c->util && merge_remote_util(c)->obj) {
-			sha1 = merge_remote_util(c)->obj->sha1;
+			oid = &merge_remote_util(c)->obj->oid;
 		} else {
-			sha1 = c->object.sha1;
+			oid = &c->object.oid;
 		}
-		strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
+		strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
 	}
 	filename = git_path_merge_head();
 	fd = open(filename, O_WRONLY | O_CREAT, 0666);
@@ -1002,7 +1014,7 @@ static int default_edit_option(void)
 	if (e) {
 		int v = git_config_maybe_bool(name, e);
 		if (v < 0)
-			die("Bad value '%s' in environment '%s'", e, name);
+			die(_("Bad value '%s' in environment '%s'"), e, name);
 		return v;
 	}
 
@@ -1103,7 +1115,7 @@ static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge
 		if (!commit) {
 			if (ptr)
 				*ptr = '\0';
-			die("not something we can merge in %s: %s",
+			die(_("not something we can merge in %s: %s"),
 			    filename, merge_names->buf + pos);
 		}
 		remotes = &commit_list_insert(commit, remotes)->next;
@@ -1137,7 +1149,7 @@ static struct commit_list *collect_parents(struct commit *head_commit,
 			struct commit *commit = get_merge_parent(argv[i]);
 			if (!commit)
 				help_unknown_ref(argv[i], "merge",
-						 "not something we can merge");
+						 _("not something we can merge"));
 			remotes = &commit_list_insert(commit, remotes)->next;
 		}
 		remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
@@ -1164,7 +1176,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	struct commit *head_commit;
 	struct strbuf buf = STRBUF_INIT;
 	const char *head_arg;
-	int flag, i, ret = 0, head_subsumed;
+	int i, ret = 0, head_subsumed;
 	int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
 	struct commit_list *common = NULL;
 	const char *best_strategy = NULL, *wt_strategy = NULL;
@@ -1178,7 +1190,7 @@ 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_sha1, &flag);
+	branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, NULL);
 	if (branch && starts_with(branch, "refs/heads/"))
 		branch += 11;
 	if (!branch || is_null_sha1(head_sha1))
@@ -1186,6 +1198,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	else
 		head_commit = lookup_commit_or_die(head_sha1, "HEAD");
 
+	init_diff_ui_defaults();
 	git_config(git_merge_config, NULL);
 
 	if (branch_mergeoptions)
@@ -1256,12 +1269,12 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			builtin_merge_options);
 
 	if (!head_commit) {
-		struct commit *remote_head;
 		/*
 		 * If the merged head is a valid one there is no reason
 		 * to forbid "git merge" into a branch yet to be born.
 		 * We do the same for "git pull".
 		 */
+		unsigned char *remote_head_sha1;
 		if (squash)
 			die(_("Squash commit into empty head not supported yet"));
 		if (fast_forward == FF_NO)
@@ -1269,13 +1282,13 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			    "an empty head"));
 		remoteheads = collect_parents(head_commit, &head_subsumed,
 					      argc, argv, NULL);
-		remote_head = remoteheads->item;
-		if (!remote_head)
+		if (!remoteheads)
 			die(_("%s - not something we can merge"), argv[0]);
 		if (remoteheads->next)
 			die(_("Can merge only exactly one commit into empty head"));
-		read_empty(remote_head->object.sha1, 0);
-		update_ref("initial pull", "HEAD", remote_head->object.sha1,
+		remote_head_sha1 = remoteheads->item->object.oid.hash;
+		read_empty(remote_head_sha1, 0);
+		update_ref("initial pull", "HEAD", remote_head_sha1,
 			   NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 		goto done;
 	}
@@ -1289,7 +1302,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	 * additional safety measure to check for it.
 	 */
 	if (!have_message &&
-	    is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
+	    is_old_style_invocation(argc, argv, head_commit->object.oid.hash)) {
 		warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
 		strbuf_addstr(&merge_msg, argv[0]);
 		head_arg = argv[1];
@@ -1317,13 +1330,13 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (verify_signatures) {
 		for (p = remoteheads; p; p = p->next) {
 			struct commit *commit = p->item;
-			char hex[41];
+			char hex[GIT_SHA1_HEXSZ + 1];
 			struct signature_check signature_check;
 			memset(&signature_check, 0, sizeof(signature_check));
 
 			check_commit_signature(commit, &signature_check);
 
-			strcpy(hex, find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
+			find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
 			switch (signature_check.result) {
 			case 'G':
 				break;
@@ -1353,7 +1366,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	for (p = remoteheads; p; p = p->next) {
 		struct commit *commit = p->item;
 		strbuf_addf(&buf, "GITHEAD_%s",
-			    sha1_to_hex(commit->object.sha1));
+			    sha1_to_hex(commit->object.oid.hash));
 		setenv(buf.buf, merge_remote_util(commit)->name, 1);
 		strbuf_reset(&buf);
 		if (fast_forward != FF_ONLY &&
@@ -1393,35 +1406,38 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		free(list);
 	}
 
-	update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
+	update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.oid.hash,
 		   NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 
-	if (remoteheads && !common)
-		; /* No common ancestors found. We need a real merge. */
-	else if (!remoteheads ||
+	if (remoteheads && !common) {
+		/* No common ancestors found. */
+		if (!allow_unrelated_histories)
+			die(_("refusing to merge unrelated histories"));
+		/* otherwise, we need a real merge. */
+	} else if (!remoteheads ||
 		 (!remoteheads->next && !common->next &&
 		  common->item == remoteheads->item)) {
 		/*
 		 * If head can reach all the merge then we are up to date.
 		 * but first the most common case of merging one remote.
 		 */
-		finish_up_to_date("Already up-to-date.");
+		finish_up_to_date(_("Already up-to-date."));
 		goto done;
 	} else if (fast_forward != FF_NO && !remoteheads->next &&
 			!common->next &&
-			!hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
+			!hashcmp(common->item->object.oid.hash, head_commit->object.oid.hash)) {
 		/* Again the most common case of merging one remote. */
 		struct strbuf msg = STRBUF_INIT;
 		struct commit *commit;
-		char hex[41];
 
-		strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
-
-		if (verbosity >= 0)
-			printf(_("Updating %s..%s\n"),
-				hex,
-				find_unique_abbrev(remoteheads->item->object.sha1,
-				DEFAULT_ABBREV));
+		if (verbosity >= 0) {
+			char from[GIT_SHA1_HEXSZ + 1], to[GIT_SHA1_HEXSZ + 1];
+			find_unique_abbrev_r(from, head_commit->object.oid.hash,
+					      DEFAULT_ABBREV);
+			find_unique_abbrev_r(to, remoteheads->item->object.oid.hash,
+					      DEFAULT_ABBREV);
+			printf(_("Updating %s..%s\n"), from, to);
+		}
 		strbuf_addstr(&msg, "Fast-forward");
 		if (have_message)
 			strbuf_addstr(&msg,
@@ -1432,14 +1448,14 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			goto done;
 		}
 
-		if (checkout_fast_forward(head_commit->object.sha1,
-					  commit->object.sha1,
+		if (checkout_fast_forward(head_commit->object.oid.hash,
+					  commit->object.oid.hash,
 					  overwrite_ignore)) {
 			ret = 1;
 			goto done;
 		}
 
-		finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
+		finish(head_commit, remoteheads, commit->object.oid.hash, msg.buf);
 		drop_save();
 		goto done;
 	} else if (!remoteheads->next && common->next)
@@ -1458,9 +1474,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			/* See if it is really trivial. */
 			git_committer_info(IDENT_STRICT);
 			printf(_("Trying really trivial in-index merge...\n"));
-			if (!read_tree_trivial(common->item->object.sha1,
-					       head_commit->object.sha1,
-					       remoteheads->item->object.sha1)) {
+			if (!read_tree_trivial(common->item->object.oid.hash,
+					       head_commit->object.oid.hash,
+					       remoteheads->item->object.oid.hash)) {
 				ret = merge_trivial(head_commit, remoteheads);
 				goto done;
 			}
@@ -1483,14 +1499,14 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			 * HEAD^^" would be missed.
 			 */
 			common_one = get_merge_bases(head_commit, j->item);
-			if (hashcmp(common_one->item->object.sha1,
-				j->item->object.sha1)) {
+			if (hashcmp(common_one->item->object.oid.hash,
+				j->item->object.oid.hash)) {
 				up_to_date = 0;
 				break;
 			}
 		}
 		if (up_to_date) {
-			finish_up_to_date("Already up-to-date. Yeeah!");
+			finish_up_to_date(_("Already up-to-date. Yeeah!"));
 			goto done;
 		}
 	}
@@ -1520,7 +1536,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		int ret;
 		if (i) {
 			printf(_("Rewinding the tree to pristine...\n"));
-			restore_state(head_commit->object.sha1, stash);
+			restore_state(head_commit->object.oid.hash, stash);
 		}
 		if (use_strategies_nr != 1)
 			printf(_("Trying merge strategy %s...\n"),
@@ -1586,7 +1602,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	 * it up.
 	 */
 	if (!best_strategy) {
-		restore_state(head_commit->object.sha1, stash);
+		restore_state(head_commit->object.oid.hash, stash);
 		if (use_strategies_nr > 1)
 			fprintf(stderr,
 				_("No merge strategy handled the merge.\n"));
@@ -1599,7 +1615,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		; /* We already have its result in the working tree. */
 	else {
 		printf(_("Rewinding the tree to pristine...\n"));
-		restore_state(head_commit->object.sha1, stash);
+		restore_state(head_commit->object.oid.hash, stash);
 		printf(_("Using the %s to prepare resolving by hand.\n"),
 			best_strategy);
 		try_merge_strategy(best_strategy, common, remoteheads,