1 files changed, 180 insertions, 121 deletions

diff --git a/builtin/merge.c b/builtin/merge.c
index 8f4a5065c2..ca6a5dc4bf 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -6,6 +6,7 @@
  * Based on git-merge.sh by Junio C Hamano.
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "config.h"
 #include "parse-options.h"
@@ -36,6 +37,10 @@
 #include "packfile.h"
 #include "tag.h"
 #include "alias.h"
+#include "branch.h"
+#include "commit-reach.h"
+#include "wt-status.h"
+#include "commit-graph.h"
 
 #define DEFAULT_TWOHEAD (1<<0)
 #define DEFAULT_OCTOPUS (1<<1)
@@ -55,9 +60,10 @@ static const char * const builtin_merge_usage[] = {
 };
 
 static int show_diffstat = 1, shortlog_len = -1, squash;
-static int option_commit = 1;
+static int option_commit = -1;
 static int option_edit = -1;
 static int allow_trivial = 1, have_message, verify_signatures;
+static int check_trust_level = 1;
 static int overwrite_ignore = 1;
 static struct strbuf merge_msg = STRBUF_INIT;
 static struct strategy **use_strategies;
@@ -70,13 +76,15 @@ static int option_renormalize;
 static int verbosity;
 static int allow_rerere_auto;
 static int abort_current_merge;
+static int quit_current_merge;
 static int continue_current_merge;
 static int allow_unrelated_histories;
 static int show_progress = -1;
 static int default_to_upstream = 1;
 static int signoff;
 static const char *sign_commit;
-static int verify_msg = 1;
+static int autostash;
+static int no_verify;
 
 static struct strategy all_strategy[] = {
 	{ "recursive",  DEFAULT_TWOHEAD | NO_TRIVIAL },
@@ -96,6 +104,9 @@ enum ff_type {
 
 static enum ff_type fast_forward = FF_ALLOW;
 
+static const char *cleanup_arg;
+static enum commit_msg_cleanup_mode cleanup_mode;
+
 static int option_parse_message(const struct option *opt,
 				const char *arg, int unset)
 {
@@ -111,12 +122,15 @@ 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)
+static enum parse_opt_result option_read_message(struct parse_opt_ctx_t *ctx,
+						 const struct option *opt,
+						 const char *arg_not_used,
+						 int unset)
 {
 	struct strbuf *buf = opt->value;
 	const char *arg;
 
+	BUG_ON_OPT_ARG(arg_not_used);
 	if (unset)
 		BUG("-F cannot be negated");
 
@@ -127,7 +141,7 @@ static int option_read_message(struct parse_opt_ctx_t *ctx,
 		ctx->argc--;
 		arg = *++ctx->argv;
 	} else
-		return opterror(opt, "requires a value", 0);
+		return error(_("option `%s' requires a value"), opt->long_name);
 
 	if (buf->len)
 		strbuf_addch(buf, '\n');
@@ -223,14 +237,15 @@ static int option_parse_x(const struct option *opt,
 static int option_parse_n(const struct option *opt,
 			  const char *arg, int unset)
 {
+	BUG_ON_OPT_ARG(arg);
 	show_diffstat = unset;
 	return 0;
 }
 
 static struct option builtin_merge_options[] = {
-	{ OPTION_CALLBACK, 'n', NULL, NULL, NULL,
+	OPT_CALLBACK_F('n', NULL, NULL, NULL,
 		N_("do not show a diffstat at the end of the merge"),
-		PARSE_OPT_NOARG, option_parse_n },
+		PARSE_OPT_NOARG, option_parse_n),
 	OPT_BOOL(0, "stat", &show_diffstat,
 		N_("show a diffstat at the end of the merge")),
 	OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
@@ -243,6 +258,7 @@ static struct option builtin_merge_options[] = {
 		N_("perform a commit if the merge succeeds (default)")),
 	OPT_BOOL('e', "edit", &option_edit,
 		N_("edit message before committing")),
+	OPT_CLEANUP(&cleanup_arg),
 	OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
 	OPT_SET_INT_F(0, "ff-only", &fast_forward,
 		      N_("abort if fast-forward is not possible"),
@@ -259,10 +275,12 @@ static struct option builtin_merge_options[] = {
 		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 },
+		NULL, 0, option_read_message },
 	OPT__VERBOSITY(&verbosity),
 	OPT_BOOL(0, "abort", &abort_current_merge,
 		N_("abort the current in-progress merge")),
+	OPT_BOOL(0, "quit", &quit_current_merge,
+		N_("--abort but leave index and working tree alone")),
 	OPT_BOOL(0, "continue", &continue_current_merge,
 		N_("continue the current in-progress merge")),
 	OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
@@ -270,20 +288,13 @@ static struct option builtin_merge_options[] = {
 	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) "" },
+	OPT_AUTOSTASH(&autostash),
 	OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
 	OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
-	OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
+	OPT_BOOL(0, "no-verify", &no_verify, N_("bypass pre-merge-commit and commit-msg hooks")),
 	OPT_END()
 };
 
-/* Cleans up metadata that is uninteresting after a succeeded merge. */
-static void drop_save(void)
-{
-	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)
 {
 	int len;
@@ -377,7 +388,7 @@ static void finish_up_to_date(const char *msg)
 {
 	if (verbosity >= 0)
 		printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
-	drop_save();
+	remove_merge_branch_state(the_repository);
 }
 
 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
@@ -389,7 +400,7 @@ static void squash_message(struct commit *commit, struct commit_list *remotehead
 
 	printf(_("Squash commit -- not updating HEAD\n"));
 
-	init_revisions(&rev, NULL);
+	repo_init_revisions(the_repository, &rev, NULL);
 	rev.ignore_merges = 1;
 	rev.commit_format = CMIT_FMT_MEDIUM;
 
@@ -439,20 +450,19 @@ static void finish(struct commit *head_commit,
 		if (verbosity >= 0 && !merge_msg.len)
 			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, head,
 				   0, UPDATE_REFS_DIE_ON_ERR);
 			/*
 			 * We ignore errors in 'gc --auto', since the
 			 * user should see them.
 			 */
-			close_all_packs(the_repository->objects);
-			run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
+			close_object_store(the_repository->objects);
+			run_auto_gc(verbosity < 0);
 		}
 	}
 	if (new_head && show_diffstat) {
 		struct diff_options opts;
-		diff_setup(&opts);
+		repo_diff_setup(the_repository, &opts);
 		opts.stat_width = -1; /* use full terminal width */
 		opts.stat_graph_width = -1; /* respect statGraphWidth config */
 		opts.output_format |=
@@ -467,6 +477,7 @@ static void finish(struct commit *head_commit,
 	/* Run a post-merge hook */
 	run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
 
+	apply_autostash(git_path_merge_autostash(the_repository));
 	strbuf_release(&reflog_message);
 }
 
@@ -576,7 +587,7 @@ static void parse_branch_merge_options(char *bmo)
 	argc = split_cmdline(bmo, &argv);
 	if (argc < 0)
 		die(_("Bad branch.%s.mergeoptions string: %s"), branch,
-		    split_cmdline_strerror(argc));
+		    _(split_cmdline_strerror(argc)));
 	REALLOC_ARRAY(argv, argc + 2);
 	MOVE_ARRAY(argv + 1, argv, argc + 1);
 	argc++;
@@ -589,10 +600,12 @@ static void parse_branch_merge_options(char *bmo)
 static int git_merge_config(const char *k, const char *v, void *cb)
 {
 	int status;
+	const char *str;
 
-	if (branch && starts_with(k, "branch.") &&
-		starts_with(k + 7, branch) &&
-		!strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
+	if (branch &&
+	    skip_prefix(k, "branch.", &str) &&
+	    skip_prefix(str, branch, &str) &&
+	    !strcmp(str, ".mergeoptions")) {
 		free(branch_mergeoptions);
 		branch_mergeoptions = xstrdup(v);
 		return 0;
@@ -606,6 +619,8 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 		return git_config_string(&pull_twohead, k, v);
 	else if (!strcmp(k, "pull.octopus"))
 		return git_config_string(&pull_octopus, k, v);
+	else if (!strcmp(k, "commit.cleanup"))
+		return git_config_string(&cleanup_arg, k, v);
 	else if (!strcmp(k, "merge.renormalize"))
 		option_renormalize = git_config_bool(k, v);
 	else if (!strcmp(k, "merge.ff")) {
@@ -622,6 +637,11 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 	} else if (!strcmp(k, "commit.gpgsign")) {
 		sign_commit = git_config_bool(k, v) ? "" : NULL;
 		return 0;
+	} else if (!strcmp(k, "gpg.mintrustlevel")) {
+		check_trust_level = 0;
+	} else if (!strcmp(k, "merge.autostash")) {
+		autostash = git_config_bool(k, v);
+		return 0;
 	}
 
 	status = fmt_merge_msg_config(k, v, cb);
@@ -679,16 +699,13 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 			      struct commit_list *remoteheads,
 			      struct commit *head)
 {
-	struct lock_file lock = LOCK_INIT;
 	const char *head_arg = "HEAD";
 
-	hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
-	refresh_cache(REFRESH_QUIET);
-	if (write_locked_index(&the_index, &lock,
-			       COMMIT_LOCK | SKIP_IF_UNCHANGED))
+	if (refresh_and_write_cache(REFRESH_QUIET, SKIP_IF_UNCHANGED, 0) < 0)
 		return error(_("Unable to write index."));
 
 	if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
+		struct lock_file lock = LOCK_INIT;
 		int clean, x;
 		struct commit *result;
 		struct commit_list *reversed = NULL;
@@ -700,7 +717,7 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 			return 2;
 		}
 
-		init_merge_options(&o);
+		init_merge_options(&o, the_repository);
 		if (!strcmp(strategy, "subtree"))
 			o.subtree_shift = "";
 
@@ -728,8 +745,9 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 			die(_("unable to write %s"), get_index_file());
 		return clean ? 0 : 1;
 	} else {
-		return try_merge_command(strategy, xopts_nr, xopts,
-						common, head_arg, remoteheads);
+		return try_merge_command(the_repository,
+					 strategy, xopts_nr, xopts,
+					 common, head_arg, remoteheads);
 	}
 }
 
@@ -793,20 +811,45 @@ static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
 static const char merge_editor_comment[] =
 N_("Please enter a commit message to explain why this merge is necessary,\n"
    "especially if it merges an updated upstream into a topic branch.\n"
-   "\n"
-   "Lines starting with '%c' will be ignored, and an empty message aborts\n"
+   "\n");
+
+static const char scissors_editor_comment[] =
+N_("An empty message aborts the commit.\n");
+
+static const char no_scissors_editor_comment[] =
+N_("Lines starting with '%c' will be ignored, and an empty message aborts\n"
    "the commit.\n");
 
 static void write_merge_heads(struct commit_list *);
 static void prepare_to_commit(struct commit_list *remoteheads)
 {
 	struct strbuf msg = STRBUF_INIT;
+	const char *index_file = get_index_file();
+
+	if (!no_verify && run_commit_hook(0 < option_edit, index_file, "pre-merge-commit", NULL))
+		abort_commit(remoteheads, NULL);
+	/*
+	 * Re-read the index as pre-merge-commit hook could have updated it,
+	 * and write it out as a tree.  We must do this before we invoke
+	 * the editor and after we invoke run_status above.
+	 */
+	if (find_hook("pre-merge-commit"))
+		discard_cache();
+	read_cache_from(index_file);
 	strbuf_addbuf(&msg, &merge_msg);
-	strbuf_addch(&msg, '\n');
 	if (squash)
 		BUG("the control must not reach here under --squash");
-	if (0 < option_edit)
-		strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
+	if (0 < option_edit) {
+		strbuf_addch(&msg, '\n');
+		if (cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS) {
+			wt_status_append_cut_line(&msg);
+			strbuf_commented_addf(&msg, "\n");
+		}
+		strbuf_commented_addf(&msg, _(merge_editor_comment));
+		strbuf_commented_addf(&msg, _(cleanup_mode == COMMIT_MSG_CLEANUP_SCISSORS ?
+			scissors_editor_comment :
+			no_scissors_editor_comment), comment_line_char);
+	}
 	if (signoff)
 		append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
 	write_merge_heads(remoteheads);
@@ -819,13 +862,13 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 			abort_commit(remoteheads, NULL);
 	}
 
-	if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
+	if (!no_verify && run_commit_hook(0 < option_edit, get_index_file(),
 					  "commit-msg",
 					  git_path_merge_msg(the_repository), NULL))
 		abort_commit(remoteheads, NULL);
 
 	read_merge_msg(&msg);
-	strbuf_stripspace(&msg, 0 < option_edit);
+	cleanup_message(&msg, cleanup_mode, 0);
 	if (!msg.len)
 		abort_commit(remoteheads, _("Empty commit message."));
 	strbuf_release(&merge_msg);
@@ -837,12 +880,8 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 {
 	struct object_id result_tree, result_commit;
 	struct commit_list *parents, **pptr = &parents;
-	struct lock_file lock = LOCK_INIT;
 
-	hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
-	refresh_cache(REFRESH_QUIET);
-	if (write_locked_index(&the_index, &lock,
-			       COMMIT_LOCK | SKIP_IF_UNCHANGED))
+	if (refresh_and_write_cache(REFRESH_QUIET, SKIP_IF_UNCHANGED, 0) < 0)
 		return error(_("Unable to write index."));
 
 	write_tree_trivial(&result_tree);
@@ -854,7 +893,7 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 			&result_commit, NULL, sign_commit))
 		die(_("failed to write commit object"));
 	finish(head, remoteheads, &result_commit, "In-index merge");
-	drop_save();
+	remove_merge_branch_state(the_repository);
 	return 0;
 }
 
@@ -869,11 +908,11 @@ static int finish_automerge(struct commit *head,
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id result_commit;
 
+	write_tree_trivial(result_tree);
 	free_commit_list(common);
 	parents = remoteheads;
 	if (!head_subsumed || fast_forward == FF_NO)
 		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, parents,
 			&result_commit, NULL, sign_commit))
@@ -881,7 +920,7 @@ static int finish_automerge(struct commit *head,
 	strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
 	finish(head, remoteheads, &result_commit, buf.buf);
 	strbuf_release(&buf);
-	drop_save();
+	remove_merge_branch_state(the_repository);
 	return 0;
 }
 
@@ -894,11 +933,19 @@ static int suggest_conflicts(void)
 	filename = git_path_merge_msg(the_repository);
 	fp = xfopen(filename, "a");
 
-	append_conflicts_hint(&msgbuf);
+	/*
+	 * We can't use cleanup_mode because if we're not using the editor,
+	 * get_cleanup_mode will return COMMIT_MSG_CLEANUP_SPACE instead, even
+	 * though the message is meant to be processed later by git-commit.
+	 * Thus, we will get the cleanup mode which is returned when we _are_
+	 * using an editor.
+	 */
+	append_conflicts_hint(&the_index, &msgbuf,
+			      get_cleanup_mode(cleanup_arg, 1));
 	fputs(msgbuf.buf, fp);
 	strbuf_release(&msgbuf);
 	fclose(fp);
-	rerere(allow_rerere_auto);
+	repo_rerere(the_repository, allow_rerere_auto);
 	printf(_("Automatic merge failed; "
 			"fix conflicts and then commit the result.\n"));
 	return 1;
@@ -910,7 +957,7 @@ static int evaluate_result(void)
 	struct rev_info rev;
 
 	/* Check how many files differ. */
-	init_revisions(&rev, "");
+	repo_init_revisions(the_repository, &rev, "");
 	setup_revisions(0, NULL, &rev, NULL);
 	rev.diffopt.output_format |=
 		DIFF_FORMAT_CALLBACK;
@@ -1189,7 +1236,7 @@ static int merging_a_throwaway_tag(struct commit *commit)
 	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))
+	    oideq(&oid, &merge_remote_util(commit)->obj->oid))
 		is_throwaway_tag = 0;
 	else
 		is_throwaway_tag = 1;
@@ -1242,6 +1289,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (abort_current_merge) {
 		int nargc = 2;
 		const char *nargv[] = {"reset", "--merge", NULL};
+		struct strbuf stash_oid = STRBUF_INIT;
 
 		if (orig_argc != 2)
 			usage_msg_opt(_("--abort expects no arguments"),
@@ -1250,8 +1298,27 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		if (!file_exists(git_path_merge_head(the_repository)))
 			die(_("There is no merge to abort (MERGE_HEAD missing)."));
 
+		if (read_oneliner(&stash_oid, git_path_merge_autostash(the_repository),
+		    READ_ONELINER_SKIP_IF_EMPTY))
+			unlink(git_path_merge_autostash(the_repository));
+
 		/* Invoke 'git reset --merge' */
 		ret = cmd_reset(nargc, nargv, prefix);
+
+		if (stash_oid.len)
+			apply_autostash_oid(stash_oid.buf);
+
+		strbuf_release(&stash_oid);
+		goto done;
+	}
+
+	if (quit_current_merge) {
+		if (orig_argc != 2)
+			usage_msg_opt(_("--quit expects no arguments"),
+				      builtin_merge_usage,
+				      builtin_merge_options);
+
+		remove_merge_branch_state(the_repository);
 		goto done;
 	}
 
@@ -1294,15 +1361,30 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	}
 	resolve_undo_clear();
 
+	if (option_edit < 0)
+		option_edit = default_edit_option();
+
+	cleanup_mode = get_cleanup_mode(cleanup_arg, 0 < option_edit);
+
 	if (verbosity < 0)
 		show_diffstat = 0;
 
 	if (squash) {
 		if (fast_forward == FF_NO)
 			die(_("You cannot combine --squash with --no-ff."));
+		if (option_commit > 0)
+			die(_("You cannot combine --squash with --commit."));
+		/*
+		 * squash can now silently disable option_commit - this is not
+		 * a problem as it is only overriding the default, not a user
+		 * supplied option.
+		 */
 		option_commit = 0;
 	}
 
+	if (option_commit < 0)
+		option_commit = 1;
+
 	if (!argc) {
 		if (default_to_upstream)
 			argc = setup_with_upstream(&argv);
@@ -1334,6 +1416,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			die(_("%s - not something we can merge"), argv[0]);
 		if (remoteheads->next)
 			die(_("Can merge only exactly one commit into empty head"));
+
+		if (verify_signatures)
+			verify_merge_signature(remoteheads->item, verbosity,
+					       check_trust_level);
+
 		remote_head_oid = &remoteheads->item->object.oid;
 		read_empty(remote_head_oid, 0);
 		update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
@@ -1355,31 +1442,8 @@ 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[GIT_MAX_HEXSZ + 1];
-			struct signature_check signature_check;
-			memset(&signature_check, 0, sizeof(signature_check));
-
-			check_commit_signature(commit, &signature_check);
-
-			find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
-			switch (signature_check.result) {
-			case 'G':
-				break;
-			case 'U':
-				die(_("Commit %s has an untrusted GPG signature, "
-				      "allegedly by %s."), hex, signature_check.signer);
-			case 'B':
-				die(_("Commit %s has a bad GPG signature "
-				      "allegedly by %s."), hex, signature_check.signer);
-			default: /* 'N' */
-				die(_("Commit %s does not have a GPG signature."), hex);
-			}
-			if (verbosity >= 0 && signature_check.result == 'G')
-				printf(_("Commit %s has a good GPG signature by %s\n"),
-				       hex, signature_check.signer);
-
-			signature_check_clear(&signature_check);
+			verify_merge_signature(p->item, verbosity,
+					       check_trust_level);
 		}
 	}
 
@@ -1399,9 +1463,6 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			fast_forward = FF_NO;
 	}
 
-	if (option_edit < 0)
-		option_edit = default_edit_option();
-
 	if (!use_strategies) {
 		if (!remoteheads)
 			; /* already up-to-date */
@@ -1448,7 +1509,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		goto done;
 	} else if (fast_forward != FF_NO && !remoteheads->next &&
 			!common->next &&
-			!oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
+			oideq(&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;
@@ -1470,7 +1531,12 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			goto done;
 		}
 
-		if (checkout_fast_forward(&head_commit->object.oid,
+		if (autostash)
+			create_autostash(the_repository,
+					 git_path_merge_autostash(the_repository),
+					 "merge");
+		if (checkout_fast_forward(the_repository,
+					  &head_commit->object.oid,
 					  &commit->object.oid,
 					  overwrite_ignore)) {
 			ret = 1;
@@ -1478,7 +1544,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		}
 
 		finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
-		drop_save();
+		remove_merge_branch_state(the_repository);
 		goto done;
 	} else if (!remoteheads->next && common->next)
 		;
@@ -1521,7 +1587,7 @@ 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 (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
+			if (!oideq(&common_one->item->object.oid, &j->item->object.oid)) {
 				up_to_date = 0;
 				break;
 			}
@@ -1535,6 +1601,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (fast_forward == FF_ONLY)
 		die(_("Not possible to fast-forward, aborting."));
 
+	if (autostash)
+		create_autostash(the_repository,
+				 git_path_merge_autostash(the_repository),
+				 "merge");
+
 	/* We are going to make a new commit. */
 	git_committer_info(IDENT_STRICT);
 
@@ -1553,8 +1624,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	    save_state(&stash))
 		oidclr(&stash);
 
-	for (i = 0; i < use_strategies_nr; i++) {
-		int ret;
+	for (i = 0; !merge_was_ok && i < use_strategies_nr; i++) {
+		int ret, cnt;
 		if (i) {
 			printf(_("Rewinding the tree to pristine...\n"));
 			restore_state(&head_commit->object.oid, &stash);
@@ -1571,40 +1642,26 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		ret = try_merge_strategy(use_strategies[i]->name,
 					 common, remoteheads,
 					 head_commit);
-		if (!option_commit && !ret) {
-			merge_was_ok = 1;
-			/*
-			 * This is necessary here just to avoid writing
-			 * the tree, but later we will *not* exit with
-			 * status code 1 because merge_was_ok is set.
-			 */
-			ret = 1;
-		}
-
-		if (ret) {
-			/*
-			 * The backend exits with 1 when conflicts are
-			 * left to be resolved, with 2 when it does not
-			 * handle the given merge at all.
-			 */
-			if (ret == 1) {
-				int cnt = evaluate_result();
-
-				if (best_cnt <= 0 || cnt <= best_cnt) {
-					best_strategy = use_strategies[i]->name;
-					best_cnt = cnt;
+		/*
+		 * The backend exits with 1 when conflicts are
+		 * left to be resolved, with 2 when it does not
+		 * handle the given merge at all.
+		 */
+		if (ret < 2) {
+			if (!ret) {
+				if (option_commit) {
+					/* Automerge succeeded. */
+					automerge_was_ok = 1;
+					break;
 				}
+				merge_was_ok = 1;
+			}
+			cnt = evaluate_result();
+			if (best_cnt <= 0 || cnt <= best_cnt) {
+				best_strategy = use_strategies[i]->name;
+				best_cnt = cnt;
 			}
-			if (merge_was_ok)
-				break;
-			else
-				continue;
 		}
-
-		/* Automerge succeeded. */
-		write_tree_trivial(&result_tree);
-		automerge_was_ok = 1;
-		break;
 	}
 
 	/*
@@ -1643,9 +1700,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 				   head_commit);
 	}
 
-	if (squash)
+	if (squash) {
 		finish(head_commit, remoteheads, NULL, NULL);
-	else
+
+		git_test_write_commit_graph_or_die();
+	} else
 		write_merge_state(remoteheads);
 
 	if (merge_was_ok)