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

diff --cc Makefile
Simple merge

diff --cc builtin-log.c
Simple merge

diff --cc builtin-rev-parse.c
Simple merge

diff --cc contrib/examples/builtin-fetch--tool.c
index 0000000000000000000000000000000000000000,3dbdf7a2887002f0d7a67a1db35bd3c72d7a9d30..cd10dbcbc90ee155e05cffb49e88defcf35c5a59
mode 000000,100644..100644
--- /dev/null
--- 2/contrib/examples/builtin-fetch--tool.c
+++ b/contrib/examples/builtin-fetch--tool.c
@@@ -1,0 -1,574 +1,574 @@@
 -              fprintf(stderr, "* %s: fast forward to %s\n",
+ #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)) {
 -              return update_ref_env("fast forward", name, sha1_new, sha1_old);
++              fprintf(stderr, "* %s: fast-forward to %s\n",
+                       name, note);
+               fprintf(stderr, "  old..new: %s..%s\n", oldh, newh);
 -                      "* %s: not updating to non-fast forward %s\n",
++              return update_ref_env("fast-forward", name, sha1_new, sha1_old);
+       }
+       if (!force) {
+               fprintf(stderr,
 -              "* %s: forcing update to non-fast forward %s\n",
++                      "* %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]);
+ }

diff --cc imap-send.c
index 6c9938a0757a3c3b440c227951462f6972923afe,04e537406e4113d5c1ead7b7e4a1a425c9b2bf09..834301cf409c311d47b22a0f7504917a32847647
--- 1/imap-send.c
--- 2/imap-send.c
+++ b/imap-send.c
@@@ -94,7 -93,8 +94,9 @@@ struct msg_data 
        unsigned int crlf:1;
  };
  
+ static const char imap_send_usage[] = "git imap-send < <mbox>";
+ 
 +#undef DRV_OK
  #define DRV_OK          0
  #define DRV_MSG_BAD     -1
  #define DRV_BOX_BAD     -2
@@@ -1370,6 -1493,12 +1372,9 @@@ int main(int argc, char **argv
  
        git_extract_argv0_path(argv[0]);
  
 -      /* init the random number generator */
 -      arc4_init();
 -
+       if (argc != 1)
+               usage(imap_send_usage);
+ 
        setup_git_directory_gently(&nongit_ok);
        git_config(git_imap_config, NULL);