1 files changed, 61 insertions, 105 deletions

diff --git a/builtin/merge.c b/builtin/merge.c
index 101ffeff4..b65eeaa87 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -30,6 +30,7 @@
 #include "fmt-merge-msg.h"
 #include "gpg-interface.h"
 #include "sequencer.h"
+#include "string-list.h"
 
 #define DEFAULT_TWOHEAD (1<<0)
 #define DEFAULT_OCTOPUS (1<<1)
@@ -64,6 +65,7 @@ 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 +212,7 @@ 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 +223,8 @@ 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) "" },
@@ -333,15 +337,9 @@ static void squash_message(struct commit *commit, struct commit_list *remotehead
 	struct rev_info rev;
 	struct strbuf out = STRBUF_INIT;
 	struct commit_list *j;
-	const char *filename;
-	int fd;
 	struct pretty_print_context ctx = {0};
 
 	printf(_("Squash commit -- not updating HEAD\n"));
-	filename = git_path_squash_msg();
-	fd = open(filename, O_WRONLY | O_CREAT, 0666);
-	if (fd < 0)
-		die_errno(_("Could not write to '%s'"), filename);
 
 	init_revisions(&rev, NULL);
 	rev.ignore_merges = 1;
@@ -368,10 +366,7 @@ static void squash_message(struct commit *commit, struct commit_list *remotehead
 			oid_to_hex(&commit->object.oid));
 		pretty_print_commit(&ctx, commit, &out);
 	}
-	if (write_in_full(fd, out.buf, out.len) != out.len)
-		die_errno(_("Writing SQUASH_MSG"));
-	if (close(fd))
-		die_errno(_("Finishing SQUASH_MSG"));
+	write_file_buf(git_path_squash_msg(), out.buf, out.len);
 	strbuf_release(&out);
 }
 
@@ -498,7 +493,7 @@ 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.oid.hash),
+				    oid_to_hex(&remote_head->object.oid),
 				    truname.buf + 11,
 				    (early ? " (early part)" : ""));
 			strbuf_release(&truname);
@@ -512,7 +507,7 @@ 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->oid.hash),
+				    oid_to_hex(&desc->obj->oid),
 				    typename(desc->obj->type),
 				    remote);
 			goto cleanup;
@@ -520,7 +515,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
 	}
 
 	strbuf_addf(msg, "%s\t\tcommit '%s'\n",
-		sha1_to_hex(remote_head->object.oid.hash), remote);
+		oid_to_hex(&remote_head->object.oid), remote);
 cleanup:
 	strbuf_release(&buf);
 	strbuf_release(&bname);
@@ -679,6 +674,8 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 		hold_locked_index(&lock, 1);
 		clean = merge_recursive(&o, head,
 				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());
@@ -709,42 +706,17 @@ static int count_unmerged_entries(void)
 	return ret;
 }
 
-static void split_merge_strategies(const char *string, struct strategy **list,
-				   int *nr, int *alloc)
-{
-	char *p, *q, *buf;
-
-	if (!string)
-		return;
-
-	buf = xstrdup(string);
-	q = buf;
-	for (;;) {
-		p = strchr(q, ' ');
-		if (!p) {
-			ALLOC_GROW(*list, *nr + 1, *alloc);
-			(*list)[(*nr)++].name = xstrdup(q);
-			free(buf);
-			return;
-		} else {
-			*p = '\0';
-			ALLOC_GROW(*list, *nr + 1, *alloc);
-			(*list)[(*nr)++].name = xstrdup(q);
-			q = ++p;
-		}
-	}
-}
-
 static void add_strategies(const char *string, unsigned attr)
 {
-	struct strategy *list = NULL;
-	int list_alloc = 0, list_nr = 0, i;
-
-	memset(&list, 0, sizeof(list));
-	split_merge_strategies(string, &list, &list_nr, &list_alloc);
-	if (list) {
-		for (i = 0; i < list_nr; i++)
-			append_strategy(get_strategy(list[i].name));
+	int i;
+
+	if (string) {
+		struct string_list list = STRING_LIST_INIT_DUP;
+		struct string_list_item *item;
+		string_list_split(&list, string, ' ', -1);
+		for_each_string_list_item(item, &list)
+			append_strategy(get_strategy(item->string));
+		string_list_clear(&list, 0);
 		return;
 	}
 	for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
@@ -753,18 +725,6 @@ static void add_strategies(const char *string, unsigned attr)
 
 }
 
-static void write_merge_msg(struct strbuf *msg)
-{
-	const char *filename = git_path_merge_msg();
-	int fd = open(filename, O_WRONLY | O_CREAT, 0666);
-	if (fd < 0)
-		die_errno(_("Could not open '%s' for writing"),
-			  filename);
-	if (write_in_full(fd, msg->buf, msg->len) != msg->len)
-		die_errno(_("Could not write to '%s'"), filename);
-	close(fd);
-}
-
 static void read_merge_msg(struct strbuf *msg)
 {
 	const char *filename = git_path_merge_msg();
@@ -798,7 +758,7 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 	strbuf_addch(&msg, '\n');
 	if (0 < option_edit)
 		strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
-	write_merge_msg(&msg);
+	write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
 	if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
 			    git_path_merge_msg(), "merge", NULL))
 		abort_commit(remoteheads, NULL);
@@ -819,6 +779,14 @@ 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"));
@@ -953,8 +921,6 @@ static int setup_with_upstream(const char ***argv)
 
 static void write_merge_state(struct commit_list *remoteheads)
 {
-	const char *filename;
-	int fd;
 	struct commit_list *j;
 	struct strbuf buf = STRBUF_INIT;
 
@@ -968,26 +934,14 @@ static void write_merge_state(struct commit_list *remoteheads)
 		}
 		strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
 	}
-	filename = git_path_merge_head();
-	fd = open(filename, O_WRONLY | O_CREAT, 0666);
-	if (fd < 0)
-		die_errno(_("Could not open '%s' for writing"), filename);
-	if (write_in_full(fd, buf.buf, buf.len) != buf.len)
-		die_errno(_("Could not write to '%s'"), filename);
-	close(fd);
+	write_file_buf(git_path_merge_head(), buf.buf, buf.len);
 	strbuf_addch(&merge_msg, '\n');
-	write_merge_msg(&merge_msg);
+	write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
 
-	filename = git_path_merge_mode();
-	fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-	if (fd < 0)
-		die_errno(_("Could not open '%s' for writing"), filename);
 	strbuf_reset(&buf);
 	if (fast_forward == FF_NO)
-		strbuf_addf(&buf, "no-ff");
-	if (write_in_full(fd, buf.buf, buf.len) != buf.len)
-		die_errno(_("Could not write to '%s'"), filename);
-	close(fd);
+		strbuf_addstr(&buf, "no-ff");
+	write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
 }
 
 static int default_edit_option(void)
@@ -1003,7 +957,7 @@ 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;
 	}
 
@@ -1104,7 +1058,7 @@ 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;
@@ -1138,7 +1092,7 @@ 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);
@@ -1165,7 +1119,7 @@ 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;
@@ -1179,7 +1133,7 @@ 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))
@@ -1187,6 +1141,7 @@ 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)
@@ -1257,12 +1212,12 @@ 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)
@@ -1270,13 +1225,13 @@ 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.oid.hash, 0);
-		update_ref("initial pull", "HEAD", remote_head->object.oid.hash,
+		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;
 	}
@@ -1354,7 +1309,7 @@ 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.oid.hash));
+			    oid_to_hex(&commit->object.oid));
 		setenv(buf.buf, merge_remote_util(commit)->name, 1);
 		strbuf_reset(&buf);
 		if (fast_forward != FF_ONLY &&
@@ -1397,31 +1352,33 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	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.oid.hash, head_commit->object.oid.hash)) {
+			!oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
 		/* Again the most common case of merging one remote. */
 		struct strbuf msg = STRBUF_INIT;
 		struct commit *commit;
 
 		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);
+			printf(_("Updating %s..%s\n"),
+			       find_unique_abbrev(head_commit->object.oid.hash,
+						  DEFAULT_ABBREV),
+			       find_unique_abbrev(remoteheads->item->object.oid.hash,
+						  DEFAULT_ABBREV));
 		}
 		strbuf_addstr(&msg, "Fast-forward");
 		if (have_message)
@@ -1484,14 +1441,13 @@ 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.oid.hash,
-				j->item->object.oid.hash)) {
+			if (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
 				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;
 		}
 	}
@@ -1515,7 +1471,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	     * Stash away the local changes so that we can try more than one.
 	     */
 	    save_state(stash))
-		hashcpy(stash, null_sha1);
+		hashclr(stash);
 
 	for (i = 0; i < use_strategies_nr; i++) {
 		int ret;