From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 23 May 2018 05:38:17 +0000 (+0900)
Subject: Merge branch 'js/deprecate-grafts'
X-Git-Tag: v2.18.0-rc0~54
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/352cf6cfe138b1dbcf9c105c91ca793b67511d7b?hp=-c

Merge branch 'js/deprecate-grafts'

The functionality of "$GIT_DIR/info/grafts" has been superseded by
the "refs/replace/" mechanism for some time now, but the internal
code had support for it in many places, which has been cleaned up
in order to drop support of the "grafts" mechanism.

* js/deprecate-grafts:
Remove obsolete script to convert grafts to replace refs
technical/shallow: describe why shallow cannot use replace refs
technical/shallow: stop referring to grafts
filter-branch: stop suggesting to use grafts
Deprecate support for .git/info/grafts
Add a test for `git replace --convert-graft-file`
replace: introduce --convert-graft-file
replace: prepare create_graft() for converting graft files wholesale
replace: "libify" create_graft() and callees
replace: avoid using die() to indicate a bug
commit: Let the callback of for_each_mergetag return on error
argv_array: offer to split a string by whitespace
---

352cf6cfe138b1dbcf9c105c91ca793b67511d7b
diff --combined advice.c
index 89fda1de55,4411704fd4..370a56d054
--- a/advice.c
+++ b/advice.c
@@@ -1,6 -1,5 +1,6 @@@
  #include "cache.h"
  #include "config.h"
 +#include "color.h"
  
  int advice_push_update_rejected = 1;
  int advice_push_non_ff_current = 1;
@@@ -20,34 -19,8 +20,35 @@@ int advice_rm_hints = 1
  int advice_add_embedded_repo = 1;
  int advice_ignored_hook = 1;
  int advice_waiting_for_editor = 1;
+ int advice_graft_file_deprecated = 1;
  
 +static int advice_use_color = -1;
 +static char advice_colors[][COLOR_MAXLEN] = {
 +	GIT_COLOR_RESET,
 +	GIT_COLOR_YELLOW,	/* HINT */
 +};
 +
 +enum color_advice {
 +	ADVICE_COLOR_RESET = 0,
 +	ADVICE_COLOR_HINT = 1,
 +};
 +
 +static int parse_advise_color_slot(const char *slot)
 +{
 +	if (!strcasecmp(slot, "reset"))
 +		return ADVICE_COLOR_RESET;
 +	if (!strcasecmp(slot, "hint"))
 +		return ADVICE_COLOR_HINT;
 +	return -1;
 +}
 +
 +static const char *advise_get_color(enum color_advice ix)
 +{
 +	if (want_color_stderr(advice_use_color))
 +		return advice_colors[ix];
 +	return "";
 +}
 +
  static struct {
  	const char *name;
  	int *preference;
@@@ -70,6 -43,7 +71,7 @@@
  	{ "addembeddedrepo", &advice_add_embedded_repo },
  	{ "ignoredhook", &advice_ignored_hook },
  	{ "waitingforeditor", &advice_waiting_for_editor },
+ 	{ "graftfiledeprecated", &advice_graft_file_deprecated },
  
  	/* make this an alias for backward compatibility */
  	{ "pushnonfastforward", &advice_push_update_rejected }
@@@ -87,10 -61,7 +89,10 @@@ void advise(const char *advice, ...
  
  	for (cp = buf.buf; *cp; cp = np) {
  		np = strchrnul(cp, '\n');
 -		fprintf(stderr,	_("hint: %.*s\n"), (int)(np - cp), cp);
 +		fprintf(stderr,	_("%shint: %.*s%s\n"),
 +			advise_get_color(ADVICE_COLOR_HINT),
 +			(int)(np - cp), cp,
 +			advise_get_color(ADVICE_COLOR_RESET));
  		if (*np)
  			np++;
  	}
@@@ -99,23 -70,9 +101,23 @@@
  
  int git_default_advice_config(const char *var, const char *value)
  {
 -	const char *k;
 +	const char *k, *slot_name;
  	int i;
  
 +	if (!strcmp(var, "color.advice")) {
 +		advice_use_color = git_config_colorbool(var, value);
 +		return 0;
 +	}
 +
 +	if (skip_prefix(var, "color.advice.", &slot_name)) {
 +		int slot = parse_advise_color_slot(slot_name);
 +		if (slot < 0)
 +			return 0;
 +		if (!value)
 +			return config_error_nonbool(var);
 +		return color_parse(value, advice_colors[slot]);
 +	}
 +
  	if (!skip_prefix(var, "advice.", &k))
  		return 0;
  
diff --combined builtin/replace.c
index 14e142d5a8,a87fca045b..6da2411e14
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@@ -14,14 -14,13 +14,15 @@@
  #include "refs.h"
  #include "parse-options.h"
  #include "run-command.h"
 +#include "object-store.h"
 +#include "repository.h"
  #include "tag.h"
  
  static const char * const git_replace_usage[] = {
  	N_("git replace [-f] <object> <replacement>"),
  	N_("git replace [-f] --edit <object>"),
  	N_("git replace [-f] --graft <commit> [<parent>...]"),
+ 	N_("git replace [-f] --convert-graft-file"),
  	N_("git replace -d <object>..."),
  	N_("git replace [--format=<format>] [-l [<pattern>]]"),
  	NULL
@@@ -55,9 -54,8 +56,9 @@@ static int show_reference(const char *r
  			if (get_oid(refname, &object))
  				return error("Failed to resolve '%s' as a valid ref.", refname);
  
 -			obj_type = oid_object_info(&object, NULL);
 -			repl_type = oid_object_info(oid, NULL);
 +			obj_type = oid_object_info(the_repository, &object,
 +						   NULL);
 +			repl_type = oid_object_info(the_repository, oid, NULL);
  
  			printf("%s (%s) -> %s (%s)\n", refname, type_name(obj_type),
  			       oid_to_hex(oid), type_name(repl_type));
@@@ -82,11 -80,11 +83,11 @@@ static int list_replace_refs(const cha
  	else if (!strcmp(format, "long"))
  		data.format = REPLACE_FORMAT_LONG;
  	else
- 		die("invalid replace format '%s'\n"
- 		    "valid formats are 'short', 'medium' and 'long'\n",
- 		    format);
+ 		return error("invalid replace format '%s'\n"
+ 			     "valid formats are 'short', 'medium' and 'long'\n",
+ 			     format);
  
 -	for_each_replace_ref(show_reference, (void *)&data);
 +	for_each_replace_ref(the_repository, show_reference, (void *)&data);
  
  	return 0;
  }
@@@ -137,7 -135,7 +138,7 @@@ static int delete_replace_ref(const cha
  	return 0;
  }
  
- static void check_ref_valid(struct object_id *object,
+ static int check_ref_valid(struct object_id *object,
  			    struct object_id *prev,
  			    struct strbuf *ref,
  			    int force)
@@@ -145,12 -143,13 +146,13 @@@
  	strbuf_reset(ref);
  	strbuf_addf(ref, "%s%s", git_replace_ref_base, oid_to_hex(object));
  	if (check_refname_format(ref->buf, 0))
- 		die("'%s' is not a valid ref name.", ref->buf);
+ 		return error("'%s' is not a valid ref name.", ref->buf);
  
  	if (read_ref(ref->buf, prev))
  		oidclr(prev);
  	else if (!force)
- 		die("replace ref '%s' already exists", ref->buf);
+ 		return error("replace ref '%s' already exists", ref->buf);
+ 	return 0;
  }
  
  static int replace_object_oid(const char *object_ref,
@@@ -164,28 -163,33 +166,33 @@@
  	struct strbuf ref = STRBUF_INIT;
  	struct ref_transaction *transaction;
  	struct strbuf err = STRBUF_INIT;
+ 	int res = 0;
  
 -	obj_type = oid_object_info(object, NULL);
 -	repl_type = oid_object_info(repl, NULL);
 +	obj_type = oid_object_info(the_repository, object, NULL);
 +	repl_type = oid_object_info(the_repository, repl, NULL);
  	if (!force && obj_type != repl_type)
- 		die("Objects must be of the same type.\n"
- 		    "'%s' points to a replaced object of type '%s'\n"
- 		    "while '%s' points to a replacement object of type '%s'.",
- 		    object_ref, type_name(obj_type),
- 		    replace_ref, type_name(repl_type));
- 
- 	check_ref_valid(object, &prev, &ref, force);
+ 		return error("Objects must be of the same type.\n"
+ 			     "'%s' points to a replaced object of type '%s'\n"
+ 			     "while '%s' points to a replacement object of "
+ 			     "type '%s'.",
+ 			     object_ref, type_name(obj_type),
+ 			     replace_ref, type_name(repl_type));
+ 
+ 	if (check_ref_valid(object, &prev, &ref, force)) {
+ 		strbuf_release(&ref);
+ 		return -1;
+ 	}
  
  	transaction = ref_transaction_begin(&err);
  	if (!transaction ||
  	    ref_transaction_update(transaction, ref.buf, repl, &prev,
  				   0, NULL, &err) ||
  	    ref_transaction_commit(transaction, &err))
- 		die("%s", err.buf);
+ 		res = error("%s", err.buf);
  
  	ref_transaction_free(transaction);
  	strbuf_release(&ref);
- 	return 0;
+ 	return res;
  }
  
  static int replace_object(const char *object_ref, const char *replace_ref, int force)
@@@ -193,9 -197,11 +200,11 @@@
  	struct object_id object, repl;
  
  	if (get_oid(object_ref, &object))
- 		die("Failed to resolve '%s' as a valid ref.", object_ref);
+ 		return error("Failed to resolve '%s' as a valid ref.",
+ 			     object_ref);
  	if (get_oid(replace_ref, &repl))
- 		die("Failed to resolve '%s' as a valid ref.", replace_ref);
+ 		return error("Failed to resolve '%s' as a valid ref.",
+ 			     replace_ref);
  
  	return replace_object_oid(object_ref, &object, replace_ref, &repl, force);
  }
@@@ -205,7 -211,7 +214,7 @@@
   * If "raw" is true, then the object's raw contents are printed according to
   * "type". Otherwise, we pretty-print the contents for human editing.
   */
- static void export_object(const struct object_id *oid, enum object_type type,
+ static int export_object(const struct object_id *oid, enum object_type type,
  			  int raw, const char *filename)
  {
  	struct child_process cmd = CHILD_PROCESS_INIT;
@@@ -213,7 -219,7 +222,7 @@@
  
  	fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  	if (fd < 0)
- 		die_errno("unable to open %s for writing", filename);
+ 		return error_errno("unable to open %s for writing", filename);
  
  	argv_array_push(&cmd.args, "--no-replace-objects");
  	argv_array_push(&cmd.args, "cat-file");
@@@ -226,7 -232,8 +235,8 @@@
  	cmd.out = fd;
  
  	if (run_command(&cmd))
- 		die("cat-file reported failure");
+ 		return error("cat-file reported failure");
+ 	return 0;
  }
  
  /*
@@@ -234,14 -241,14 +244,14 @@@
   * interpreting it as "type", and writing the result to the object database.
   * The sha1 of the written object is returned via sha1.
   */
- static void import_object(struct object_id *oid, enum object_type type,
+ static int import_object(struct object_id *oid, enum object_type type,
  			  int raw, const char *filename)
  {
  	int fd;
  
  	fd = open(filename, O_RDONLY);
  	if (fd < 0)
- 		die_errno("unable to open %s for reading", filename);
+ 		return error_errno("unable to open %s for reading", filename);
  
  	if (!raw && type == OBJ_TREE) {
  		const char *argv[] = { "mktree", NULL };
@@@ -253,27 -260,40 +263,40 @@@
  		cmd.in = fd;
  		cmd.out = -1;
  
- 		if (start_command(&cmd))
- 			die("unable to spawn mktree");
+ 		if (start_command(&cmd)) {
+ 			close(fd);
+ 			return error("unable to spawn mktree");
+ 		}
  
- 		if (strbuf_read(&result, cmd.out, 41) < 0)
- 			die_errno("unable to read from mktree");
+ 		if (strbuf_read(&result, cmd.out, 41) < 0) {
+ 			error_errno("unable to read from mktree");
+ 			close(fd);
+ 			close(cmd.out);
+ 			return -1;
+ 		}
  		close(cmd.out);
  
- 		if (finish_command(&cmd))
- 			die("mktree reported failure");
- 		if (get_oid_hex(result.buf, oid) < 0)
- 			die("mktree did not return an object name");
+ 		if (finish_command(&cmd)) {
+ 			strbuf_release(&result);
+ 			return error("mktree reported failure");
+ 		}
+ 		if (get_oid_hex(result.buf, oid) < 0) {
+ 			strbuf_release(&result);
+ 			return error("mktree did not return an object name");
+ 		}
  
  		strbuf_release(&result);
  	} else {
  		struct stat st;
  		int flags = HASH_FORMAT_CHECK | HASH_WRITE_OBJECT;
  
- 		if (fstat(fd, &st) < 0)
- 			die_errno("unable to fstat %s", filename);
+ 		if (fstat(fd, &st) < 0) {
+ 			error_errno("unable to fstat %s", filename);
+ 			close(fd);
+ 			return -1;
+ 		}
  		if (index_fd(oid, fd, &st, type, NULL, flags) < 0)
- 			die("unable to write object to database");
+ 			return error("unable to write object to database");
  		/* index_fd close()s fd for us */
  	}
  
@@@ -281,30 -301,43 +304,43 @@@
  	 * No need to close(fd) here; both run-command and index-fd
  	 * will have done it for us.
  	 */
+ 	return 0;
  }
  
  static int edit_and_replace(const char *object_ref, int force, int raw)
  {
- 	char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
+ 	char *tmpfile;
  	enum object_type type;
  	struct object_id old_oid, new_oid, prev;
  	struct strbuf ref = STRBUF_INIT;
  
  	if (get_oid(object_ref, &old_oid) < 0)
- 		die("Not a valid object name: '%s'", object_ref);
+ 		return error("Not a valid object name: '%s'", object_ref);
  
 -	type = oid_object_info(&old_oid, NULL);
 +	type = oid_object_info(the_repository, &old_oid, NULL);
  	if (type < 0)
- 		die("unable to get object type for %s", oid_to_hex(&old_oid));
+ 		return error("unable to get object type for %s",
+ 			     oid_to_hex(&old_oid));
  
- 	check_ref_valid(&old_oid, &prev, &ref, force);
+ 	if (check_ref_valid(&old_oid, &prev, &ref, force)) {
+ 		strbuf_release(&ref);
+ 		return -1;
+ 	}
  	strbuf_release(&ref);
  
- 	export_object(&old_oid, type, raw, tmpfile);
- 	if (launch_editor(tmpfile, NULL, NULL) < 0)
- 		die("editing object file failed");
- 	import_object(&new_oid, type, raw, tmpfile);
- 
+ 	tmpfile = git_pathdup("REPLACE_EDITOBJ");
+ 	if (export_object(&old_oid, type, raw, tmpfile)) {
+ 		free(tmpfile);
+ 		return -1;
+ 	}
+ 	if (launch_editor(tmpfile, NULL, NULL) < 0) {
+ 		free(tmpfile);
+ 		return error("editing object file failed");
+ 	}
+ 	if (import_object(&new_oid, type, raw, tmpfile)) {
+ 		free(tmpfile);
+ 		return -1;
+ 	}
  	free(tmpfile);
  
  	if (!oidcmp(&old_oid, &new_oid))
@@@ -313,7 -346,7 +349,7 @@@
  	return replace_object_oid(object_ref, &old_oid, "replacement", &new_oid, force);
  }
  
- static void replace_parents(struct strbuf *buf, int argc, const char **argv)
+ static int replace_parents(struct strbuf *buf, int argc, const char **argv)
  {
  	struct strbuf new_parents = STRBUF_INIT;
  	const char *parent_start, *parent_end;
@@@ -330,9 -363,15 +366,15 @@@
  	/* prepare new parents */
  	for (i = 0; i < argc; i++) {
  		struct object_id oid;
- 		if (get_oid(argv[i], &oid) < 0)
- 			die(_("Not a valid object name: '%s'"), argv[i]);
- 		lookup_commit_or_die(&oid, argv[i]);
+ 		if (get_oid(argv[i], &oid) < 0) {
+ 			strbuf_release(&new_parents);
+ 			return error(_("Not a valid object name: '%s'"),
+ 				     argv[i]);
+ 		}
+ 		if (!lookup_commit_reference(&oid)) {
+ 			strbuf_release(&new_parents);
+ 			return error(_("could not parse %s"), argv[i]);
+ 		}
  		strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&oid));
  	}
  
@@@ -341,6 -380,7 +383,7 @@@
  		      new_parents.buf, new_parents.len);
  
  	strbuf_release(&new_parents);
+ 	return 0;
  }
  
  struct check_mergetag_data {
@@@ -348,7 -388,7 +391,7 @@@
  	const char **argv;
  };
  
- static void check_one_mergetag(struct commit *commit,
+ static int check_one_mergetag(struct commit *commit,
  			       struct commit_extra_header *extra,
  			       void *data)
  {
@@@ -361,33 -401,35 +404,35 @@@
  	hash_object_file(extra->value, extra->len, type_name(OBJ_TAG), &tag_oid);
  	tag = lookup_tag(&tag_oid);
  	if (!tag)
- 		die(_("bad mergetag in commit '%s'"), ref);
+ 		return error(_("bad mergetag in commit '%s'"), ref);
  	if (parse_tag_buffer(tag, extra->value, extra->len))
- 		die(_("malformed mergetag in commit '%s'"), ref);
+ 		return error(_("malformed mergetag in commit '%s'"), ref);
  
  	/* iterate over new parents */
  	for (i = 1; i < mergetag_data->argc; i++) {
  		struct object_id oid;
  		if (get_oid(mergetag_data->argv[i], &oid) < 0)
- 			die(_("Not a valid object name: '%s'"), mergetag_data->argv[i]);
+ 			return error(_("Not a valid object name: '%s'"),
+ 				     mergetag_data->argv[i]);
  		if (!oidcmp(&tag->tagged->oid, &oid))
- 			return; /* found */
+ 			return 0; /* found */
  	}
  
- 	die(_("original commit '%s' contains mergetag '%s' that is discarded; "
- 	      "use --edit instead of --graft"), ref, oid_to_hex(&tag_oid));
+ 	return error(_("original commit '%s' contains mergetag '%s' that is "
+ 		       "discarded; use --edit instead of --graft"), ref,
+ 		     oid_to_hex(&tag_oid));
  }
  
- static void check_mergetags(struct commit *commit, int argc, const char **argv)
+ static int check_mergetags(struct commit *commit, int argc, const char **argv)
  {
  	struct check_mergetag_data mergetag_data;
  
  	mergetag_data.argc = argc;
  	mergetag_data.argv = argv;
- 	for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
+ 	return for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
  }
  
- static int create_graft(int argc, const char **argv, int force)
+ static int create_graft(int argc, const char **argv, int force, int gentle)
  {
  	struct object_id old_oid, new_oid;
  	const char *old_ref = argv[0];
@@@ -397,33 -439,81 +442,81 @@@
  	unsigned long size;
  
  	if (get_oid(old_ref, &old_oid) < 0)
- 		die(_("Not a valid object name: '%s'"), old_ref);
- 	commit = lookup_commit_or_die(&old_oid, old_ref);
+ 		return error(_("Not a valid object name: '%s'"), old_ref);
+ 	commit = lookup_commit_reference(&old_oid);
+ 	if (!commit)
+ 		return error(_("could not parse %s"), old_ref);
  
  	buffer = get_commit_buffer(commit, &size);
  	strbuf_add(&buf, buffer, size);
  	unuse_commit_buffer(commit, buffer);
  
- 	replace_parents(&buf, argc - 1, &argv[1]);
+ 	if (replace_parents(&buf, argc - 1, &argv[1]) < 0) {
+ 		strbuf_release(&buf);
+ 		return -1;
+ 	}
  
  	if (remove_signature(&buf)) {
  		warning(_("the original commit '%s' has a gpg signature."), old_ref);
  		warning(_("the signature will be removed in the replacement commit!"));
  	}
  
- 	check_mergetags(commit, argc, argv);
+ 	if (check_mergetags(commit, argc, argv)) {
+ 		strbuf_release(&buf);
+ 		return -1;
+ 	}
  
- 	if (write_object_file(buf.buf, buf.len, commit_type, &new_oid))
- 		die(_("could not write replacement commit for: '%s'"), old_ref);
+ 	if (write_object_file(buf.buf, buf.len, commit_type, &new_oid)) {
+ 		strbuf_release(&buf);
+ 		return error(_("could not write replacement commit for: '%s'"),
+ 			     old_ref);
+ 	}
  
  	strbuf_release(&buf);
  
- 	if (!oidcmp(&old_oid, &new_oid))
+ 	if (!oidcmp(&old_oid, &new_oid)) {
+ 		if (gentle) {
+ 			warning("graft for '%s' unnecessary", oid_to_hex(&old_oid));
+ 			return 0;
+ 		}
  		return error("new commit is the same as the old one: '%s'", oid_to_hex(&old_oid));
+ 	}
  
  	return replace_object_oid(old_ref, &old_oid, "replacement", &new_oid, force);
  }
  
+ static int convert_graft_file(int force)
+ {
+ 	const char *graft_file = get_graft_file();
+ 	FILE *fp = fopen_or_warn(graft_file, "r");
+ 	struct strbuf buf = STRBUF_INIT, err = STRBUF_INIT;
+ 	struct argv_array args = ARGV_ARRAY_INIT;
+ 
+ 	if (!fp)
+ 		return -1;
+ 
+ 	while (strbuf_getline(&buf, fp) != EOF) {
+ 		if (*buf.buf == '#')
+ 			continue;
+ 
+ 		argv_array_split(&args, buf.buf);
+ 		if (args.argc && create_graft(args.argc, args.argv, force, 1))
+ 			strbuf_addf(&err, "\n\t%s", buf.buf);
+ 		argv_array_clear(&args);
+ 	}
+ 	fclose(fp);
+ 
+ 	strbuf_release(&buf);
+ 
+ 	if (!err.len)
+ 		return unlink_or_warn(graft_file);
+ 
+ 	warning(_("could not convert the following graft(s):\n%s"), err.buf);
+ 	strbuf_release(&err);
+ 
+ 	return -1;
+ }
+ 
  int cmd_replace(int argc, const char **argv, const char *prefix)
  {
  	int force = 0;
@@@ -435,6 -525,7 +528,7 @@@
  		MODE_DELETE,
  		MODE_EDIT,
  		MODE_GRAFT,
+ 		MODE_CONVERT_GRAFT_FILE,
  		MODE_REPLACE
  	} cmdmode = MODE_UNSPECIFIED;
  	struct option options[] = {
@@@ -442,6 -533,7 +536,7 @@@
  		OPT_CMDMODE('d', "delete", &cmdmode, N_("delete replace refs"), MODE_DELETE),
  		OPT_CMDMODE('e', "edit", &cmdmode, N_("edit existing object"), MODE_EDIT),
  		OPT_CMDMODE('g', "graft", &cmdmode, N_("change a commit's parents"), MODE_GRAFT),
+ 		OPT_CMDMODE(0, "convert-graft-file", &cmdmode, N_("convert existing graft file"), MODE_CONVERT_GRAFT_FILE),
  		OPT_BOOL_F('f', "force", &force, N_("replace the ref if it exists"),
  			   PARSE_OPT_NOCOMPLETE),
  		OPT_BOOL(0, "raw", &raw, N_("do not pretty-print contents for --edit")),
@@@ -464,7 -556,8 +559,8 @@@
  	if (force &&
  	    cmdmode != MODE_REPLACE &&
  	    cmdmode != MODE_EDIT &&
- 	    cmdmode != MODE_GRAFT)
+ 	    cmdmode != MODE_GRAFT &&
+ 	    cmdmode != MODE_CONVERT_GRAFT_FILE)
  		usage_msg_opt("-f only makes sense when writing a replacement",
  			      git_replace_usage, options);
  
@@@ -495,7 -588,13 +591,13 @@@
  		if (argc < 1)
  			usage_msg_opt("-g needs at least one argument",
  				      git_replace_usage, options);
- 		return create_graft(argc, argv, force);
+ 		return create_graft(argc, argv, force, 0);
+ 
+ 	case MODE_CONVERT_GRAFT_FILE:
+ 		if (argc != 0)
+ 			usage_msg_opt("--convert-graft-file takes no argument",
+ 				      git_replace_usage, options);
+ 		return !!convert_graft_file(force);
  
  	case MODE_LIST:
  		if (argc > 1)
@@@ -504,6 -603,6 +606,6 @@@
  		return list_replace_refs(argv[0], format);
  
  	default:
- 		die("BUG: invalid cmdmode %d", (int)cmdmode);
+ 		BUG("invalid cmdmode %d", (int)cmdmode);
  	}
  }
diff --combined commit.c
index 1d7622b2cc,451d3ce8df..f9714ed74c
--- a/commit.c
+++ b/commit.c
@@@ -1,7 -1,6 +1,7 @@@
  #include "cache.h"
  #include "tag.h"
  #include "commit.h"
 +#include "commit-graph.h"
  #include "pkt-line.h"
  #include "utf8.h"
  #include "diff.h"
@@@ -13,6 -12,7 +13,7 @@@
  #include "prio-queue.h"
  #include "sha1-lookup.h"
  #include "wt-status.h"
+ #include "advice.h"
  
  static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
  
@@@ -177,6 -177,15 +178,15 @@@ static int read_graft_file(const char *
  	struct strbuf buf = STRBUF_INIT;
  	if (!fp)
  		return -1;
+ 	if (advice_graft_file_deprecated)
+ 		advise(_("Support for <GIT_DIR>/info/grafts is deprecated\n"
+ 			 "and will be removed in a future Git version.\n"
+ 			 "\n"
+ 			 "Please use \"git replace --convert-graft-file\"\n"
+ 			 "to convert the grafts into replace refs.\n"
+ 			 "\n"
+ 			 "Turn this message off by running\n"
+ 			 "\"git config advice.graftFileDeprecated false\""));
  	while (!strbuf_getwholeline(&buf, fp, '\n')) {
  		/* The format is just "Commit Parent1 Parent2 ...\n" */
  		struct commit_graft *graft = read_graft_line(&buf);
@@@ -296,22 -305,6 +306,22 @@@ void free_commit_buffer(struct commit *
  	}
  }
  
 +struct tree *get_commit_tree(const struct commit *commit)
 +{
 +	if (commit->maybe_tree || !commit->object.parsed)
 +		return commit->maybe_tree;
 +
 +	if (commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
 +		BUG("commit has NULL tree, but was not loaded from commit-graph");
 +
 +	return get_commit_tree_in_graph(commit);
 +}
 +
 +struct object_id *get_commit_tree_oid(const struct commit *commit)
 +{
 +	return &get_commit_tree(commit)->object.oid;
 +}
 +
  const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
  {
  	struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
@@@ -351,7 -344,7 +361,7 @@@ int parse_commit_buffer(struct commit *
  	if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
  		return error("bad tree pointer in commit %s",
  			     oid_to_hex(&item->object.oid));
 -	item->tree = lookup_tree(&parent);
 +	item->maybe_tree = lookup_tree(&parent);
  	bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
  	pptr = &item->parents;
  
@@@ -400,8 -393,6 +410,8 @@@ int parse_commit_gently(struct commit *
  		return -1;
  	if (item->object.parsed)
  		return 0;
 +	if (parse_commit_in_graph(item))
 +		return 0;
  	buffer = read_object_file(&item->object.oid, &type, &size);
  	if (!buffer)
  		return quiet_on_missing ? -1 :
@@@ -1307,17 -1298,19 +1317,19 @@@ struct commit_extra_header *read_commit
  	return extra;
  }
  
- void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
+ int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
  {
  	struct commit_extra_header *extra, *to_free;
+ 	int res = 0;
  
  	to_free = read_commit_extra_headers(commit, NULL);
- 	for (extra = to_free; extra; extra = extra->next) {
+ 	for (extra = to_free; !res && extra; extra = extra->next) {
  		if (strcmp(extra->key, "mergetag"))
  			continue; /* not a merge tag */
- 		fn(commit, extra, data);
+ 		res = fn(commit, extra, data);
  	}
  	free_commit_extra_headers(to_free);
+ 	return res;
  }
  
  static inline int standard_header_field(const char *field, size_t len)
diff --combined commit.h
index 23a3f364ed,9000895ad9..10e34e1a18
--- a/commit.h
+++ b/commit.h
@@@ -9,8 -9,6 +9,8 @@@
  #include "string-list.h"
  #include "pretty.h"
  
 +#define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
 +
  struct commit_list {
  	struct commit *item;
  	struct commit_list *next;
@@@ -22,14 -20,7 +22,14 @@@ struct commit 
  	unsigned int index;
  	timestamp_t date;
  	struct commit_list *parents;
 -	struct tree *tree;
 +
 +	/*
 +	 * If the commit is loaded from the commit-graph file, then this
 +	 * member may be NULL. Only access it through get_commit_tree()
 +	 * or get_commit_tree_oid().
 +	 */
 +	struct tree *maybe_tree;
 +	uint32_t graph_pos;
  };
  
  extern int save_commit_buffer;
@@@ -108,9 -99,6 +108,9 @@@ void unuse_commit_buffer(const struct c
   */
  void free_commit_buffer(struct commit *);
  
 +struct tree *get_commit_tree(const struct commit *);
 +struct object_id *get_commit_tree_oid(const struct commit *);
 +
  /*
   * Disassociate any cached object buffer from the commit, but do not free it.
   * The buffer (or NULL, if none) is returned.
@@@ -303,10 -291,10 +303,10 @@@ extern const char *find_commit_header(c
  /* Find the end of the log message, the right place for a new trailer. */
  extern int ignore_non_trailer(const char *buf, size_t len);
  
- typedef void (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
+ typedef int (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
  				 void *cb_data);
  
- extern void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
+ extern int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
  
  struct merge_remote_desc {
  	struct object *obj; /* the named object, could be a tag */
diff --combined log-tree.c
index 2e6b486140,f3a51a6e72..66329d089d
--- a/log-tree.c
+++ b/log-tree.c
@@@ -488,9 -488,9 +488,9 @@@ static int is_common_merge(const struc
  		&& !commit->parents->next->next);
  }
  
- static void show_one_mergetag(struct commit *commit,
- 			      struct commit_extra_header *extra,
- 			      void *data)
+ static int show_one_mergetag(struct commit *commit,
+ 			     struct commit_extra_header *extra,
+ 			     void *data)
  {
  	struct rev_info *opt = (struct rev_info *)data;
  	struct object_id oid;
@@@ -502,7 -502,7 +502,7 @@@
  	hash_object_file(extra->value, extra->len, type_name(OBJ_TAG), &oid);
  	tag = lookup_tag(&oid);
  	if (!tag)
- 		return; /* error message already given */
+ 		return -1; /* error message already given */
  
  	strbuf_init(&verify_message, 256);
  	if (parse_tag_buffer(tag, extra->value, extra->len))
@@@ -536,11 -536,12 +536,12 @@@
  
  	show_sig_lines(opt, status, verify_message.buf);
  	strbuf_release(&verify_message);
+ 	return 0;
  }
  
- static void show_mergetag(struct rev_info *opt, struct commit *commit)
+ static int show_mergetag(struct rev_info *opt, struct commit *commit)
  {
- 	for_each_mergetag(show_one_mergetag, commit, opt);
+ 	return for_each_mergetag(show_one_mergetag, commit, opt);
  }
  
  void show_log(struct rev_info *opt)
@@@ -806,7 -807,7 +807,7 @@@ static int log_tree_diff(struct rev_inf
  		return 0;
  
  	parse_commit_or_die(commit);
 -	oid = &commit->tree->object.oid;
 +	oid = get_commit_tree_oid(commit);
  
  	/* Root commit? */
  	parents = get_saved_parents(opt, commit);
@@@ -831,7 -832,7 +832,7 @@@
  			 * we merged _in_.
  			 */
  			parse_commit_or_die(parents->item);
 -			diff_tree_oid(&parents->item->tree->object.oid,
 +			diff_tree_oid(get_commit_tree_oid(parents->item),
  				      oid, "", &opt->diffopt);
  			log_tree_diff_flush(opt);
  			return !opt->loginfo;
@@@ -846,7 -847,7 +847,7 @@@
  		struct commit *parent = parents->item;
  
  		parse_commit_or_die(parent);
 -		diff_tree_oid(&parent->tree->object.oid,
 +		diff_tree_oid(get_commit_tree_oid(parent),
  			      oid, "", &opt->diffopt);
  		log_tree_diff_flush(opt);