From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 27 Jul 2014 22:14:18 +0000 (-0700)
Subject: Merge branch 'cc/replace-graft'
X-Git-Tag: v2.1.0-rc0~2
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/16737445a94cb9b18378fff973129d974c7cdf8a?ds=inline;hp=-c

Merge branch 'cc/replace-graft'

"git replace" learned a "--graft" option to rewrite parents of a
commit.

* cc/replace-graft:
replace: add test for --graft with a mergetag
replace: check mergetags when using --graft
replace: add test for --graft with signed commit
replace: remove signature when using --graft
contrib: add convert-grafts-to-replace-refs.sh
Documentation: replace: add --graft option
replace: add test for --graft
replace: add --graft option
replace: cleanup redirection style in tests
---

16737445a94cb9b18378fff973129d974c7cdf8a
diff --combined Documentation/git-replace.txt
index 089dcac047,e1be2e6270..8fff598fd6
--- a/Documentation/git-replace.txt
+++ b/Documentation/git-replace.txt
@@@ -10,6 -10,7 +10,7 @@@ SYNOPSI
  [verse]
  'git replace' [-f] <object> <replacement>
  'git replace' [-f] --edit <object>
+ 'git replace' [-f] --graft <commit> [<parent>...]
  'git replace' -d <object>...
  'git replace' [--format=<format>] [-l [<pattern>]]
  
@@@ -73,14 -74,15 +74,23 @@@ OPTION
  	newly created object. See linkgit:git-var[1] for details about
  	how the editor will be chosen.
  
 +--raw::
 +	When editing, provide the raw object contents rather than
 +	pretty-printed ones. Currently this only affects trees, which
 +	will be shown in their binary form. This is harder to work with,
 +	but can help when repairing a tree that is so corrupted it
 +	cannot be pretty-printed. Note that you may need to configure
 +	your editor to cleanly read and write binary data.
 +
+ --graft <commit> [<parent>...]::
+ 	Create a graft commit. A new commit is created with the same
+ 	content as <commit> except that its parents will be
+ 	[<parent>...] instead of <commit>'s parents. A replacement ref
+ 	is then created to replace <commit> with the newly created
+ 	commit. See contrib/convert-grafts-to-replace-refs.sh for an
+ 	example script based on this option that can convert grafts to
+ 	replace refs.
+ 
  -l <pattern>::
  --list <pattern>::
  	List replace refs for objects that match the given pattern (or
diff --combined builtin/replace.c
index d1ea2c2e56,d29026fe21..294b61b97e
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@@ -13,19 -13,21 +13,21 @@@
  #include "refs.h"
  #include "parse-options.h"
  #include "run-command.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 -d <object>..."),
  	N_("git replace [--format=<format>] [-l [<pattern>]]"),
  	NULL
  };
  
  enum replace_format {
 -      REPLACE_FORMAT_SHORT,
 -      REPLACE_FORMAT_MEDIUM,
 -      REPLACE_FORMAT_LONG
 +	REPLACE_FORMAT_SHORT,
 +	REPLACE_FORMAT_MEDIUM,
 +	REPLACE_FORMAT_LONG
  };
  
  struct show_data {
@@@ -188,32 -190,27 +190,32 @@@ static int replace_object(const char *o
  }
  
  /*
 - * Write the contents of the object named by "sha1" to the file "filename",
 - * pretty-printed for human editing based on its type.
 + * Write the contents of the object named by "sha1" to the file "filename".
 + * 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 unsigned char *sha1, const char *filename)
 +static void export_object(const unsigned char *sha1, enum object_type type,
 +			  int raw, const char *filename)
  {
 -	const char *argv[] = { "--no-replace-objects", "cat-file", "-p", NULL, NULL };
 -	struct child_process cmd = { argv };
 +	struct child_process cmd = { NULL };
  	int fd;
  
  	fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  	if (fd < 0)
  		die_errno("unable to open %s for writing", filename);
  
 -	argv[3] = sha1_to_hex(sha1);
 +	argv_array_push(&cmd.args, "--no-replace-objects");
 +	argv_array_push(&cmd.args, "cat-file");
 +	if (raw)
 +		argv_array_push(&cmd.args, typename(type));
 +	else
 +		argv_array_push(&cmd.args, "-p");
 +	argv_array_push(&cmd.args, sha1_to_hex(sha1));
  	cmd.git_cmd = 1;
  	cmd.out = fd;
  
  	if (run_command(&cmd))
  		die("cat-file reported failure");
 -
 -	close(fd);
  }
  
  /*
@@@ -222,7 -219,7 +224,7 @@@
   * The sha1 of the written object is returned via sha1.
   */
  static void import_object(unsigned char *sha1, enum object_type type,
 -			  const char *filename)
 +			  int raw, const char *filename)
  {
  	int fd;
  
@@@ -230,7 -227,7 +232,7 @@@
  	if (fd < 0)
  		die_errno("unable to open %s for reading", filename);
  
 -	if (type == OBJ_TREE) {
 +	if (!raw && type == OBJ_TREE) {
  		const char *argv[] = { "mktree", NULL };
  		struct child_process cmd = { argv };
  		struct strbuf result = STRBUF_INIT;
@@@ -270,7 -267,7 +272,7 @@@
  	 */
  }
  
 -static int edit_and_replace(const char *object_ref, int force)
 +static int edit_and_replace(const char *object_ref, int force, int raw)
  {
  	char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
  	enum object_type type;
@@@ -286,10 -283,10 +288,10 @@@
  
  	check_ref_valid(old, prev, ref, sizeof(ref), force);
  
 -	export_object(old, tmpfile);
 +	export_object(old, type, raw, tmpfile);
  	if (launch_editor(tmpfile, NULL, NULL) < 0)
  		die("editing object file failed");
 -	import_object(new, type, tmpfile);
 +	import_object(new, type, raw, tmpfile);
  
  	free(tmpfile);
  
@@@ -299,24 -296,135 +301,137 @@@
  	return replace_object_sha1(object_ref, old, "replacement", new, force);
  }
  
+ static void replace_parents(struct strbuf *buf, int argc, const char **argv)
+ {
+ 	struct strbuf new_parents = STRBUF_INIT;
+ 	const char *parent_start, *parent_end;
+ 	int i;
+ 
+ 	/* find existing parents */
+ 	parent_start = buf->buf;
+ 	parent_start += 46; /* "tree " + "hex sha1" + "\n" */
+ 	parent_end = parent_start;
+ 
+ 	while (starts_with(parent_end, "parent "))
+ 		parent_end += 48; /* "parent " + "hex sha1" + "\n" */
+ 
+ 	/* prepare new parents */
+ 	for (i = 0; i < argc; i++) {
+ 		unsigned char sha1[20];
+ 		if (get_sha1(argv[i], sha1) < 0)
+ 			die(_("Not a valid object name: '%s'"), argv[i]);
+ 		lookup_commit_or_die(sha1, argv[i]);
+ 		strbuf_addf(&new_parents, "parent %s\n", sha1_to_hex(sha1));
+ 	}
+ 
+ 	/* replace existing parents with new ones */
+ 	strbuf_splice(buf, parent_start - buf->buf, parent_end - parent_start,
+ 		      new_parents.buf, new_parents.len);
+ 
+ 	strbuf_release(&new_parents);
+ }
+ 
+ struct check_mergetag_data {
+ 	int argc;
+ 	const char **argv;
+ };
+ 
+ static void check_one_mergetag(struct commit *commit,
+ 			       struct commit_extra_header *extra,
+ 			       void *data)
+ {
+ 	struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
+ 	const char *ref = mergetag_data->argv[0];
+ 	unsigned char tag_sha1[20];
+ 	struct tag *tag;
+ 	int i;
+ 
+ 	hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_sha1);
+ 	tag = lookup_tag(tag_sha1);
+ 	if (!tag)
+ 		die(_("bad mergetag in commit '%s'"), ref);
+ 	if (parse_tag_buffer(tag, extra->value, extra->len))
+ 		die(_("malformed mergetag in commit '%s'"), ref);
+ 
+ 	/* iterate over new parents */
+ 	for (i = 1; i < mergetag_data->argc; i++) {
+ 		unsigned char sha1[20];
+ 		if (get_sha1(mergetag_data->argv[i], sha1) < 0)
+ 			die(_("Not a valid object name: '%s'"), mergetag_data->argv[i]);
+ 		if (!hashcmp(tag->tagged->sha1, sha1))
+ 			return; /* found */
+ 	}
+ 
+ 	die(_("original commit '%s' contains mergetag '%s' that is discarded; "
+ 	      "use --edit instead of --graft"), ref, sha1_to_hex(tag_sha1));
+ }
+ 
+ static void 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);
+ }
+ 
+ static int create_graft(int argc, const char **argv, int force)
+ {
+ 	unsigned char old[20], new[20];
+ 	const char *old_ref = argv[0];
+ 	struct commit *commit;
+ 	struct strbuf buf = STRBUF_INIT;
+ 	const char *buffer;
+ 	unsigned long size;
+ 
+ 	if (get_sha1(old_ref, old) < 0)
+ 		die(_("Not a valid object name: '%s'"), old_ref);
+ 	commit = lookup_commit_or_die(old, 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 (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 (write_sha1_file(buf.buf, buf.len, commit_type, new))
+ 		die(_("could not write replacement commit for: '%s'"), old_ref);
+ 
+ 	strbuf_release(&buf);
+ 
+ 	if (!hashcmp(old, new))
+ 		return error("new commit is the same as the old one: '%s'", sha1_to_hex(old));
+ 
+ 	return replace_object_sha1(old_ref, old, "replacement", new, force);
+ }
+ 
  int cmd_replace(int argc, const char **argv, const char *prefix)
  {
  	int force = 0;
 +	int raw = 0;
  	const char *format = NULL;
  	enum {
  		MODE_UNSPECIFIED = 0,
  		MODE_LIST,
  		MODE_DELETE,
  		MODE_EDIT,
+ 		MODE_GRAFT,
  		MODE_REPLACE
  	} cmdmode = MODE_UNSPECIFIED;
  	struct option options[] = {
  		OPT_CMDMODE('l', "list", &cmdmode, N_("list replace refs"), MODE_LIST),
  		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_BOOL('f', "force", &force, N_("replace the ref if it exists")),
 +		OPT_BOOL(0, "raw", &raw, N_("do not pretty-print contents for --edit")),
  		OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
  		OPT_END()
  	};
@@@ -332,14 -440,13 +447,17 @@@
  		usage_msg_opt("--format cannot be used when not listing",
  			      git_replace_usage, options);
  
- 	if (force && cmdmode != MODE_REPLACE && cmdmode != MODE_EDIT)
+ 	if (force &&
+ 	    cmdmode != MODE_REPLACE &&
+ 	    cmdmode != MODE_EDIT &&
+ 	    cmdmode != MODE_GRAFT)
  		usage_msg_opt("-f only makes sense when writing a replacement",
  			      git_replace_usage, options);
  
 +	if (raw && cmdmode != MODE_EDIT)
 +		usage_msg_opt("--raw only makes sense with --edit",
 +			      git_replace_usage, options);
 +
  	switch (cmdmode) {
  	case MODE_DELETE:
  		if (argc < 1)
@@@ -357,8 -464,14 +475,14 @@@
  		if (argc != 1)
  			usage_msg_opt("-e needs exactly one argument",
  				      git_replace_usage, options);
 -		return edit_and_replace(argv[0], force);
 +		return edit_and_replace(argv[0], force, raw);
  
+ 	case MODE_GRAFT:
+ 		if (argc < 1)
+ 			usage_msg_opt("-g needs at least one argument",
+ 				      git_replace_usage, options);
+ 		return create_graft(argc, argv, force);
+ 
  	case MODE_LIST:
  		if (argc > 1)
  			usage_msg_opt("only one pattern can be given with -l",
diff --combined commit.c
index 2274e43fdf,ca26c69452..ae7f2b10f4
--- a/commit.c
+++ b/commit.c
@@@ -18,6 -18,19 +18,6 @@@ int save_commit_buffer = 1
  
  const char *commit_type = "commit";
  
 -static struct commit *check_commit(struct object *obj,
 -				   const unsigned char *sha1,
 -				   int quiet)
 -{
 -	if (obj->type != OBJ_COMMIT) {
 -		if (!quiet)
 -			error("Object %s is a %s, not a commit",
 -			      sha1_to_hex(sha1), typename(obj->type));
 -		return NULL;
 -	}
 -	return (struct commit *) obj;
 -}
 -
  struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  					      int quiet)
  {
@@@ -25,7 -38,7 +25,7 @@@
  
  	if (!obj)
  		return NULL;
 -	return check_commit(obj, sha1, quiet);
 +	return object_as_type(obj, OBJ_COMMIT, quiet);
  }
  
  struct commit *lookup_commit_reference(const unsigned char *sha1)
@@@ -48,9 -61,13 +48,9 @@@ struct commit *lookup_commit_or_die(con
  struct commit *lookup_commit(const unsigned char *sha1)
  {
  	struct object *obj = lookup_object(sha1);
 -	if (!obj) {
 -		struct commit *c = alloc_commit_node();
 -		return create_object(sha1, OBJ_COMMIT, c);
 -	}
 -	if (!obj->type)
 -		obj->type = OBJ_COMMIT;
 -	return check_commit(obj, sha1, 0);
 +	if (!obj)
 +		return create_object(sha1, alloc_commit_node());
 +	return object_as_type(obj, OBJ_COMMIT, 0);
  }
  
  struct commit *lookup_commit_reference_by_name(const char *name)
@@@ -430,7 -447,12 +430,7 @@@ struct commit_list *copy_commit_list(st
  	struct commit_list *head = NULL;
  	struct commit_list **pp = &head;
  	while (list) {
 -		struct commit_list *new;
 -		new = xmalloc(sizeof(struct commit_list));
 -		new->item = list->item;
 -		new->next = NULL;
 -		*pp = new;
 -		pp = &new->next;
 +		pp = commit_list_append(list->item, pp);
  		list = list->next;
  	}
  	return head;
@@@ -592,7 -614,8 +592,7 @@@ static void record_author_date(struct a
  
  	for (buf = buffer; buf; buf = line_end + 1) {
  		line_end = strchrnul(buf, '\n');
 -		ident_line = skip_prefix(buf, "author ");
 -		if (!ident_line) {
 +		if (!skip_prefix(buf, "author ", &ident_line)) {
  			if (!line_end[0] || line_end[1] == '\n')
  				return; /* end of header */
  			continue;
@@@ -764,41 -787,45 +764,41 @@@ void sort_in_topological_order(struct c
  
  static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
  
 -static struct commit *interesting(struct commit_list *list)
 +static int queue_has_nonstale(struct prio_queue *queue)
  {
 -	while (list) {
 -		struct commit *commit = list->item;
 -		list = list->next;
 -		if (commit->object.flags & STALE)
 -			continue;
 -		return commit;
 +	int i;
 +	for (i = 0; i < queue->nr; i++) {
 +		struct commit *commit = queue->array[i].data;
 +		if (!(commit->object.flags & STALE))
 +			return 1;
  	}
 -	return NULL;
 +	return 0;
  }
  
  /* all input commits in one and twos[] must have been parsed! */
  static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
  {
 -	struct commit_list *list = NULL;
 +	struct prio_queue queue = { compare_commits_by_commit_date };
  	struct commit_list *result = NULL;
  	int i;
  
  	one->object.flags |= PARENT1;
 -	commit_list_insert_by_date(one, &list);
 -	if (!n)
 -		return list;
 +	if (!n) {
 +		commit_list_append(one, &result);
 +		return result;
 +	}
 +	prio_queue_put(&queue, one);
 +
  	for (i = 0; i < n; i++) {
  		twos[i]->object.flags |= PARENT2;
 -		commit_list_insert_by_date(twos[i], &list);
 +		prio_queue_put(&queue, twos[i]);
  	}
  
 -	while (interesting(list)) {
 -		struct commit *commit;
 +	while (queue_has_nonstale(&queue)) {
 +		struct commit *commit = prio_queue_get(&queue);
  		struct commit_list *parents;
 -		struct commit_list *next;
  		int flags;
  
 -		commit = list->item;
 -		next = list->next;
 -		free(list);
 -		list = next;
 -
  		flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
  		if (flags == (PARENT1 | PARENT2)) {
  			if (!(commit->object.flags & RESULT)) {
@@@ -817,11 -844,11 +817,11 @@@
  			if (parse_commit(p))
  				return NULL;
  			p->object.flags |= flags;
 -			commit_list_insert_by_date(p, &list);
 +			prio_queue_put(&queue, p);
  		}
  	}
  
 -	free_commit_list(list);
 +	clear_prio_queue(&queue);
  	return result;
  }
  
@@@ -966,7 -993,12 +966,7 @@@ struct commit_list *get_merge_bases_man
  	}
  
  	/* There are more than one */
 -	cnt = 0;
 -	list = result;
 -	while (list) {
 -		list = list->next;
 -		cnt++;
 -	}
 +	cnt = commit_list_count(result);
  	rslt = xcalloc(cnt, sizeof(*rslt));
  	for (list = result, i = 0; list; list = list->next)
  		rslt[i++] = list->item;
@@@ -1146,6 -1178,40 +1146,40 @@@ int parse_signed_commit(const struct co
  	return saw_signature;
  }
  
+ int remove_signature(struct strbuf *buf)
+ {
+ 	const char *line = buf->buf;
+ 	const char *tail = buf->buf + buf->len;
+ 	int in_signature = 0;
+ 	const char *sig_start = NULL;
+ 	const char *sig_end = NULL;
+ 
+ 	while (line < tail) {
+ 		const char *next = memchr(line, '\n', tail - line);
+ 		next = next ? next + 1 : tail;
+ 
+ 		if (in_signature && line[0] == ' ')
+ 			sig_end = next;
+ 		else if (starts_with(line, gpg_sig_header) &&
+ 			 line[gpg_sig_header_len] == ' ') {
+ 			sig_start = line;
+ 			sig_end = next;
+ 			in_signature = 1;
+ 		} else {
+ 			if (*line == '\n')
+ 				/* dump the whole remainder of the buffer */
+ 				next = tail;
+ 			in_signature = 0;
+ 		}
+ 		line = next;
+ 	}
+ 
+ 	if (sig_start)
+ 		strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
+ 
+ 	return sig_start != NULL;
+ }
+ 
  static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
  {
  	struct merge_remote_desc *desc;
@@@ -1205,7 -1271,8 +1239,7 @@@ static void parse_gpg_output(struct sig
  	for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
  		const char *found, *next;
  
 -		found = skip_prefix(buf, sigcheck_gpg_status[i].check + 1);
 -		if (!found) {
 +		if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
  			found = strstr(buf, sigcheck_gpg_status[i].check);
  			if (!found)
  				continue;
@@@ -1239,7 -1306,6 +1273,7 @@@ void check_commit_signature(const struc
  				      &gpg_output, &gpg_status);
  	if (status && !gpg_output.len)
  		goto out;
 +	sigc->payload = strbuf_detach(&payload, NULL);
  	sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
  	sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
  	parse_gpg_output(sigc);
diff --combined commit.h
index f43079c0c3,c81ba8530c..a8cbf52f15
--- a/commit.h
+++ b/commit.h
@@@ -271,7 -271,6 +271,7 @@@ extern void assign_shallow_commits_to_r
  					   int *ref_status);
  extern int delayed_reachability_test(struct shallow_info *si, int c);
  extern void prune_shallow(int show_only);
 +extern struct trace_key trace_shallow;
  
  int is_descendant_of(struct commit *, struct commit_list *);
  int in_merge_bases(struct commit *, struct commit *);
@@@ -333,6 -332,8 +333,8 @@@ struct commit *get_merge_parent(const c
  
  extern int parse_signed_commit(const struct commit *commit,
  			       struct strbuf *message, struct strbuf *signature);
+ extern int remove_signature(struct strbuf *buf);
+ 
  extern void print_commit_list(struct commit_list *list,
  			      const char *format_cur,
  			      const char *format_last);