Merge branch 'jn/help-everywhere'

* jn/help-everywhere: (23 commits)
  diff --no-index: make the usage string less scary
  merge-{recursive,subtree}: use usagef() to print usage
  Introduce usagef() that takes a printf-style format
  Let 'git <command> -h' show usage without a git dir
  Show usage string for 'git http-push -h'
  Let 'git http-fetch -h' show usage outside any git repository
  Show usage string for 'git stripspace -h'
  Show usage string for 'git unpack-file -h'
  Show usage string for 'git show-index -h'
  Show usage string for 'git rev-parse -h'
  Show usage string for 'git merge-one-file -h'
  Show usage string for 'git mailsplit -h'
  Show usage string for 'git imap-send -h'
  Show usage string for 'git get-tar-commit-id -h'
  Show usage string for 'git fast-import -h'
  Show usage string for 'git check-ref-format -h'
  http-fetch: add missing initialization of argv0_path
  Show usage string for 'git show-ref -h'
  Show usage string for 'git merge-ours -h'
  Show usage string for 'git commit-tree -h'
  ...

Conflicts:
	imap-send.c

1 files changed, 574 insertions, 0 deletions

diff --git a/contrib/examples/builtin-fetch--tool.c b/contrib/examples/builtin-fetch--tool.c
new file mode 100644
index 000000000..cd10dbcbc
--- /dev/null
+++ b/contrib/examples/builtin-fetch--tool.c
@@ -0,0 +1,574 @@
+#include "builtin.h"
+#include "cache.h"
+#include "refs.h"
+#include "commit.h"
+#include "sigchain.h"
+
+static char *get_stdin(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	if (strbuf_read(&buf, 0, 1024) < 0) {
+		die_errno("error reading standard input");
+	}
+	return strbuf_detach(&buf, NULL);
+}
+
+static void show_new(enum object_type type, unsigned char *sha1_new)
+{
+	fprintf(stderr, "  %s: %s\n", typename(type),
+		find_unique_abbrev(sha1_new, DEFAULT_ABBREV));
+}
+
+static int update_ref_env(const char *action,
+		      const char *refname,
+		      unsigned char *sha1,
+		      unsigned char *oldval)
+{
+	char msg[1024];
+	const char *rla = getenv("GIT_REFLOG_ACTION");
+
+	if (!rla)
+		rla = "(reflog update)";
+	if (snprintf(msg, sizeof(msg), "%s: %s", rla, action) >= sizeof(msg))
+		warning("reflog message too long: %.*s...", 50, msg);
+	return update_ref(msg, refname, sha1, oldval, 0, QUIET_ON_ERR);
+}
+
+static int update_local_ref(const char *name,
+			    const char *new_head,
+			    const char *note,
+			    int verbose, int force)
+{
+	unsigned char sha1_old[20], sha1_new[20];
+	char oldh[41], newh[41];
+	struct commit *current, *updated;
+	enum object_type type;
+
+	if (get_sha1_hex(new_head, sha1_new))
+		die("malformed object name %s", new_head);
+
+	type = sha1_object_info(sha1_new, NULL);
+	if (type < 0)
+		die("object %s not found", new_head);
+
+	if (!*name) {
+		/* Not storing */
+		if (verbose) {
+			fprintf(stderr, "* fetched %s\n", note);
+			show_new(type, sha1_new);
+		}
+		return 0;
+	}
+
+	if (get_sha1(name, sha1_old)) {
+		const char *msg;
+	just_store:
+		/* new ref */
+		if (!strncmp(name, "refs/tags/", 10))
+			msg = "storing tag";
+		else
+			msg = "storing head";
+		fprintf(stderr, "* %s: storing %s\n",
+			name, note);
+		show_new(type, sha1_new);
+		return update_ref_env(msg, name, sha1_new, NULL);
+	}
+
+	if (!hashcmp(sha1_old, sha1_new)) {
+		if (verbose) {
+			fprintf(stderr, "* %s: same as %s\n", name, note);
+			show_new(type, sha1_new);
+		}
+		return 0;
+	}
+
+	if (!strncmp(name, "refs/tags/", 10)) {
+		fprintf(stderr, "* %s: updating with %s\n", name, note);
+		show_new(type, sha1_new);
+		return update_ref_env("updating tag", name, sha1_new, NULL);
+	}
+
+	current = lookup_commit_reference(sha1_old);
+	updated = lookup_commit_reference(sha1_new);
+	if (!current || !updated)
+		goto just_store;
+
+	strcpy(oldh, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
+	strcpy(newh, find_unique_abbrev(sha1_new, DEFAULT_ABBREV));
+
+	if (in_merge_bases(current, &updated, 1)) {
+		fprintf(stderr, "* %s: fast-forward to %s\n",
+			name, note);
+		fprintf(stderr, "  old..new: %s..%s\n", oldh, newh);
+		return update_ref_env("fast-forward", name, sha1_new, sha1_old);
+	}
+	if (!force) {
+		fprintf(stderr,
+			"* %s: not updating to non-fast-forward %s\n",
+			name, note);
+		fprintf(stderr,
+			"  old...new: %s...%s\n", oldh, newh);
+		return 1;
+	}
+	fprintf(stderr,
+		"* %s: forcing update to non-fast-forward %s\n",
+		name, note);
+	fprintf(stderr, "  old...new: %s...%s\n", oldh, newh);
+	return update_ref_env("forced-update", name, sha1_new, sha1_old);
+}
+
+static int append_fetch_head(FILE *fp,
+			     const char *head, const char *remote,
+			     const char *remote_name, const char *remote_nick,
+			     const char *local_name, int not_for_merge,
+			     int verbose, int force)
+{
+	struct commit *commit;
+	int remote_len, i, note_len;
+	unsigned char sha1[20];
+	char note[1024];
+	const char *what, *kind;
+
+	if (get_sha1(head, sha1))
+		return error("Not a valid object name: %s", head);
+	commit = lookup_commit_reference_gently(sha1, 1);
+	if (!commit)
+		not_for_merge = 1;
+
+	if (!strcmp(remote_name, "HEAD")) {
+		kind = "";
+		what = "";
+	}
+	else if (!strncmp(remote_name, "refs/heads/", 11)) {
+		kind = "branch";
+		what = remote_name + 11;
+	}
+	else if (!strncmp(remote_name, "refs/tags/", 10)) {
+		kind = "tag";
+		what = remote_name + 10;
+	}
+	else if (!strncmp(remote_name, "refs/remotes/", 13)) {
+		kind = "remote branch";
+		what = remote_name + 13;
+	}
+	else {
+		kind = "";
+		what = remote_name;
+	}
+
+	remote_len = strlen(remote);
+	for (i = remote_len - 1; remote[i] == '/' && 0 <= i; i--)
+		;
+	remote_len = i + 1;
+	if (4 < i && !strncmp(".git", remote + i - 3, 4))
+		remote_len = i - 3;
+
+	note_len = 0;
+	if (*what) {
+		if (*kind)
+			note_len += sprintf(note + note_len, "%s ", kind);
+		note_len += sprintf(note + note_len, "'%s' of ", what);
+	}
+	note_len += sprintf(note + note_len, "%.*s", remote_len, remote);
+	fprintf(fp, "%s\t%s\t%s\n",
+		sha1_to_hex(commit ? commit->object.sha1 : sha1),
+		not_for_merge ? "not-for-merge" : "",
+		note);
+	return update_local_ref(local_name, head, note, verbose, force);
+}
+
+static char *keep;
+static void remove_keep(void)
+{
+	if (keep && *keep)
+		unlink(keep);
+}
+
+static void remove_keep_on_signal(int signo)
+{
+	remove_keep();
+	sigchain_pop(signo);
+	raise(signo);
+}
+
+static char *find_local_name(const char *remote_name, const char *refs,
+			     int *force_p, int *not_for_merge_p)
+{
+	const char *ref = refs;
+	int len = strlen(remote_name);
+
+	while (ref) {
+		const char *next;
+		int single_force, not_for_merge;
+
+		while (*ref == '\n')
+			ref++;
+		if (!*ref)
+			break;
+		next = strchr(ref, '\n');
+
+		single_force = not_for_merge = 0;
+		if (*ref == '+') {
+			single_force = 1;
+			ref++;
+		}
+		if (*ref == '.') {
+			not_for_merge = 1;
+			ref++;
+			if (*ref == '+') {
+				single_force = 1;
+				ref++;
+			}
+		}
+		if (!strncmp(remote_name, ref, len) && ref[len] == ':') {
+			const char *local_part = ref + len + 1;
+			int retlen;
+
+			if (!next)
+				retlen = strlen(local_part);
+			else
+				retlen = next - local_part;
+			*force_p = single_force;
+			*not_for_merge_p = not_for_merge;
+			return xmemdupz(local_part, retlen);
+		}
+		ref = next;
+	}
+	return NULL;
+}
+
+static int fetch_native_store(FILE *fp,
+			      const char *remote,
+			      const char *remote_nick,
+			      const char *refs,
+			      int verbose, int force)
+{
+	char buffer[1024];
+	int err = 0;
+
+	sigchain_push_common(remove_keep_on_signal);
+	atexit(remove_keep);
+
+	while (fgets(buffer, sizeof(buffer), stdin)) {
+		int len;
+		char *cp;
+		char *local_name;
+		int single_force, not_for_merge;
+
+		for (cp = buffer; *cp && !isspace(*cp); cp++)
+			;
+		if (*cp)
+			*cp++ = 0;
+		len = strlen(cp);
+		if (len && cp[len-1] == '\n')
+			cp[--len] = 0;
+		if (!strcmp(buffer, "failed"))
+			die("Fetch failure: %s", remote);
+		if (!strcmp(buffer, "pack"))
+			continue;
+		if (!strcmp(buffer, "keep")) {
+			char *od = get_object_directory();
+			int len = strlen(od) + strlen(cp) + 50;
+			keep = xmalloc(len);
+			sprintf(keep, "%s/pack/pack-%s.keep", od, cp);
+			continue;
+		}
+
+		local_name = find_local_name(cp, refs,
+					     &single_force, &not_for_merge);
+		if (!local_name)
+			continue;
+		err |= append_fetch_head(fp,
+					 buffer, remote, cp, remote_nick,
+					 local_name, not_for_merge,
+					 verbose, force || single_force);
+	}
+	return err;
+}
+
+static int parse_reflist(const char *reflist)
+{
+	const char *ref;
+
+	printf("refs='");
+	for (ref = reflist; ref; ) {
+		const char *next;
+		while (*ref && isspace(*ref))
+			ref++;
+		if (!*ref)
+			break;
+		for (next = ref; *next && !isspace(*next); next++)
+			;
+		printf("\n%.*s", (int)(next - ref), ref);
+		ref = next;
+	}
+	printf("'\n");
+
+	printf("rref='");
+	for (ref = reflist; ref; ) {
+		const char *next, *colon;
+		while (*ref && isspace(*ref))
+			ref++;
+		if (!*ref)
+			break;
+		for (next = ref; *next && !isspace(*next); next++)
+			;
+		if (*ref == '.')
+			ref++;
+		if (*ref == '+')
+			ref++;
+		colon = strchr(ref, ':');
+		putchar('\n');
+		printf("%.*s", (int)((colon ? colon : next) - ref), ref);
+		ref = next;
+	}
+	printf("'\n");
+	return 0;
+}
+
+static int expand_refs_wildcard(const char *ls_remote_result, int numrefs,
+				const char **refs)
+{
+	int i, matchlen, replacelen;
+	int found_one = 0;
+	const char *remote = *refs++;
+	numrefs--;
+
+	if (numrefs == 0) {
+		fprintf(stderr, "Nothing specified for fetching with remote.%s.fetch\n",
+			remote);
+		printf("empty\n");
+	}
+
+	for (i = 0; i < numrefs; i++) {
+		const char *ref = refs[i];
+		const char *lref = ref;
+		const char *colon;
+		const char *tail;
+		const char *ls;
+		const char *next;
+
+		if (*lref == '+')
+			lref++;
+		colon = strchr(lref, ':');
+		tail = lref + strlen(lref);
+		if (!(colon &&
+		      2 < colon - lref &&
+		      colon[-1] == '*' &&
+		      colon[-2] == '/' &&
+		      2 < tail - (colon + 1) &&
+		      tail[-1] == '*' &&
+		      tail[-2] == '/')) {
+			/* not a glob */
+			if (!found_one++)
+				printf("explicit\n");
+			printf("%s\n", ref);
+			continue;
+		}
+
+		/* glob */
+		if (!found_one++)
+			printf("glob\n");
+
+		/* lref to colon-2 is remote hierarchy name;
+		 * colon+1 to tail-2 is local.
+		 */
+		matchlen = (colon-1) - lref;
+		replacelen = (tail-1) - (colon+1);
+		for (ls = ls_remote_result; ls; ls = next) {
+			const char *eol;
+			unsigned char sha1[20];
+			int namelen;
+
+			while (*ls && isspace(*ls))
+				ls++;
+			next = strchr(ls, '\n');
+			eol = !next ? (ls + strlen(ls)) : next;
+			if (!memcmp("^{}", eol-3, 3))
+				continue;
+			if (eol - ls < 40)
+				continue;
+			if (get_sha1_hex(ls, sha1))
+				continue;
+			ls += 40;
+			while (ls < eol && isspace(*ls))
+				ls++;
+			/* ls to next (or eol) is the name.
+			 * is it identical to lref to colon-2?
+			 */
+			if ((eol - ls) <= matchlen ||
+			    strncmp(ls, lref, matchlen))
+				continue;
+
+			/* Yes, it is a match */
+			namelen = eol - ls;
+			if (lref != ref)
+				putchar('+');
+			printf("%.*s:%.*s%.*s\n",
+			       namelen, ls,
+			       replacelen, colon + 1,
+			       namelen - matchlen, ls + matchlen);
+		}
+	}
+	return 0;
+}
+
+static int pick_rref(int sha1_only, const char *rref, const char *ls_remote_result)
+{
+	int err = 0;
+	int lrr_count = lrr_count, i, pass;
+	const char *cp;
+	struct lrr {
+		const char *line;
+		const char *name;
+		int namelen;
+		int shown;
+	} *lrr_list = lrr_list;
+
+	for (pass = 0; pass < 2; pass++) {
+		/* pass 0 counts and allocates, pass 1 fills... */
+		cp = ls_remote_result;
+		i = 0;
+		while (1) {
+			const char *np;
+			while (*cp && isspace(*cp))
+				cp++;
+			if (!*cp)
+				break;
+			np = strchrnul(cp, '\n');
+			if (pass) {
+				lrr_list[i].line = cp;
+				lrr_list[i].name = cp + 41;
+				lrr_list[i].namelen = np - (cp + 41);
+			}
+			i++;
+			cp = np;
+		}
+		if (!pass) {
+			lrr_count = i;
+			lrr_list = xcalloc(lrr_count, sizeof(*lrr_list));
+		}
+	}
+
+	while (1) {
+		const char *next;
+		int rreflen;
+		int i;
+
+		while (*rref && isspace(*rref))
+			rref++;
+		if (!*rref)
+			break;
+		next = strchrnul(rref, '\n');
+		rreflen = next - rref;
+
+		for (i = 0; i < lrr_count; i++) {
+			struct lrr *lrr = &(lrr_list[i]);
+
+			if (rreflen == lrr->namelen &&
+			    !memcmp(lrr->name, rref, rreflen)) {
+				if (!lrr->shown)
+					printf("%.*s\n",
+					       sha1_only ? 40 : lrr->namelen + 41,
+					       lrr->line);
+				lrr->shown = 1;
+				break;
+			}
+		}
+		if (lrr_count <= i) {
+			error("pick-rref: %.*s not found", rreflen, rref);
+			err = 1;
+		}
+		rref = next;
+	}
+	free(lrr_list);
+	return err;
+}
+
+int cmd_fetch__tool(int argc, const char **argv, const char *prefix)
+{
+	int verbose = 0;
+	int force = 0;
+	int sopt = 0;
+
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp("-v", arg))
+			verbose = 1;
+		else if (!strcmp("-f", arg))
+			force = 1;
+		else if (!strcmp("-s", arg))
+			sopt = 1;
+		else
+			break;
+		argc--;
+		argv++;
+	}
+
+	if (argc <= 1)
+		return error("Missing subcommand");
+
+	if (!strcmp("append-fetch-head", argv[1])) {
+		int result;
+		FILE *fp;
+		char *filename;
+
+		if (argc != 8)
+			return error("append-fetch-head takes 6 args");
+		filename = git_path("FETCH_HEAD");
+		fp = fopen(filename, "a");
+		if (!fp)
+			return error("cannot open %s: %s\n", filename, strerror(errno));
+		result = append_fetch_head(fp, argv[2], argv[3],
+					   argv[4], argv[5],
+					   argv[6], !!argv[7][0],
+					   verbose, force);
+		fclose(fp);
+		return result;
+	}
+	if (!strcmp("native-store", argv[1])) {
+		int result;
+		FILE *fp;
+		char *filename;
+
+		if (argc != 5)
+			return error("fetch-native-store takes 3 args");
+		filename = git_path("FETCH_HEAD");
+		fp = fopen(filename, "a");
+		if (!fp)
+			return error("cannot open %s: %s\n", filename, strerror(errno));
+		result = fetch_native_store(fp, argv[2], argv[3], argv[4],
+					    verbose, force);
+		fclose(fp);
+		return result;
+	}
+	if (!strcmp("parse-reflist", argv[1])) {
+		const char *reflist;
+		if (argc != 3)
+			return error("parse-reflist takes 1 arg");
+		reflist = argv[2];
+		if (!strcmp(reflist, "-"))
+			reflist = get_stdin();
+		return parse_reflist(reflist);
+	}
+	if (!strcmp("pick-rref", argv[1])) {
+		const char *ls_remote_result;
+		if (argc != 4)
+			return error("pick-rref takes 2 args");
+		ls_remote_result = argv[3];
+		if (!strcmp(ls_remote_result, "-"))
+			ls_remote_result = get_stdin();
+		return pick_rref(sopt, argv[2], ls_remote_result);
+	}
+	if (!strcmp("expand-refs-wildcard", argv[1])) {
+		const char *reflist;
+		if (argc < 4)
+			return error("expand-refs-wildcard takes at least 2 args");
+		reflist = argv[2];
+		if (!strcmp(reflist, "-"))
+			reflist = get_stdin();
+		return expand_refs_wildcard(reflist, argc - 3, argv + 3);
+	}
+
+	return error("Unknown subcommand: %s", argv[1]);
+}