bisect--helper: `get_terms` & `bisect_terms` shell function in C
[git] / transport.c
1 #include "cache.h"
2 #include "config.h"
3 #include "transport.h"
4 #include "run-command.h"
5 #include "pkt-line.h"
6 #include "fetch-pack.h"
7 #include "remote.h"
8 #include "connect.h"
9 #include "send-pack.h"
10 #include "walker.h"
11 #include "bundle.h"
12 #include "dir.h"
13 #include "refs.h"
14 #include "refspec.h"
15 #include "branch.h"
16 #include "url.h"
17 #include "submodule.h"
18 #include "string-list.h"
19 #include "sha1-array.h"
20 #include "sigchain.h"
21 #include "transport-internal.h"
22 #include "protocol.h"
23 #include "object-store.h"
24 #include "color.h"
25
26 static int transport_use_color = -1;
27 static char transport_colors[][COLOR_MAXLEN] = {
28         GIT_COLOR_RESET,
29         GIT_COLOR_RED           /* REJECTED */
30 };
31
32 enum color_transport {
33         TRANSPORT_COLOR_RESET = 0,
34         TRANSPORT_COLOR_REJECTED = 1
35 };
36
37 static int transport_color_config(void)
38 {
39         const char *keys[] = {
40                 "color.transport.reset",
41                 "color.transport.rejected"
42         }, *key = "color.transport";
43         char *value;
44         int i;
45         static int initialized;
46
47         if (initialized)
48                 return 0;
49         initialized = 1;
50
51         if (!git_config_get_string(key, &value))
52                 transport_use_color = git_config_colorbool(key, value);
53
54         if (!want_color_stderr(transport_use_color))
55                 return 0;
56
57         for (i = 0; i < ARRAY_SIZE(keys); i++)
58                 if (!git_config_get_string(keys[i], &value)) {
59                         if (!value)
60                                 return config_error_nonbool(keys[i]);
61                         if (color_parse(value, transport_colors[i]) < 0)
62                                 return -1;
63                 }
64
65         return 0;
66 }
67
68 static const char *transport_get_color(enum color_transport ix)
69 {
70         if (want_color_stderr(transport_use_color))
71                 return transport_colors[ix];
72         return "";
73 }
74
75 static void set_upstreams(struct transport *transport, struct ref *refs,
76         int pretend)
77 {
78         struct ref *ref;
79         for (ref = refs; ref; ref = ref->next) {
80                 const char *localname;
81                 const char *tmp;
82                 const char *remotename;
83                 int flag = 0;
84                 /*
85                  * Check suitability for tracking. Must be successful /
86                  * already up-to-date ref create/modify (not delete).
87                  */
88                 if (ref->status != REF_STATUS_OK &&
89                         ref->status != REF_STATUS_UPTODATE)
90                         continue;
91                 if (!ref->peer_ref)
92                         continue;
93                 if (is_null_oid(&ref->new_oid))
94                         continue;
95
96                 /* Follow symbolic refs (mainly for HEAD). */
97                 localname = ref->peer_ref->name;
98                 remotename = ref->name;
99                 tmp = resolve_ref_unsafe(localname, RESOLVE_REF_READING,
100                                          NULL, &flag);
101                 if (tmp && flag & REF_ISSYMREF &&
102                         starts_with(tmp, "refs/heads/"))
103                         localname = tmp;
104
105                 /* Both source and destination must be local branches. */
106                 if (!localname || !starts_with(localname, "refs/heads/"))
107                         continue;
108                 if (!remotename || !starts_with(remotename, "refs/heads/"))
109                         continue;
110
111                 if (!pretend)
112                         install_branch_config(BRANCH_CONFIG_VERBOSE,
113                                 localname + 11, transport->remote->name,
114                                 remotename);
115                 else
116                         printf(_("Would set upstream of '%s' to '%s' of '%s'\n"),
117                                 localname + 11, remotename + 11,
118                                 transport->remote->name);
119         }
120 }
121
122 struct bundle_transport_data {
123         int fd;
124         struct bundle_header header;
125 };
126
127 static struct ref *get_refs_from_bundle(struct transport *transport,
128                                         int for_push,
129                                         const struct argv_array *ref_prefixes)
130 {
131         struct bundle_transport_data *data = transport->data;
132         struct ref *result = NULL;
133         int i;
134
135         if (for_push)
136                 return NULL;
137
138         if (data->fd > 0)
139                 close(data->fd);
140         data->fd = read_bundle_header(transport->url, &data->header);
141         if (data->fd < 0)
142                 die(_("could not read bundle '%s'"), transport->url);
143         for (i = 0; i < data->header.references.nr; i++) {
144                 struct ref_list_entry *e = data->header.references.list + i;
145                 struct ref *ref = alloc_ref(e->name);
146                 oidcpy(&ref->old_oid, &e->oid);
147                 ref->next = result;
148                 result = ref;
149         }
150         return result;
151 }
152
153 static int fetch_refs_from_bundle(struct transport *transport,
154                                int nr_heads, struct ref **to_fetch)
155 {
156         struct bundle_transport_data *data = transport->data;
157         return unbundle(&data->header, data->fd,
158                         transport->progress ? BUNDLE_VERBOSE : 0);
159 }
160
161 static int close_bundle(struct transport *transport)
162 {
163         struct bundle_transport_data *data = transport->data;
164         if (data->fd > 0)
165                 close(data->fd);
166         free(data);
167         return 0;
168 }
169
170 struct git_transport_data {
171         struct git_transport_options options;
172         struct child_process *conn;
173         int fd[2];
174         unsigned got_remote_heads : 1;
175         enum protocol_version version;
176         struct oid_array extra_have;
177         struct oid_array shallow;
178 };
179
180 static int set_git_option(struct git_transport_options *opts,
181                           const char *name, const char *value)
182 {
183         if (!strcmp(name, TRANS_OPT_UPLOADPACK)) {
184                 opts->uploadpack = value;
185                 return 0;
186         } else if (!strcmp(name, TRANS_OPT_RECEIVEPACK)) {
187                 opts->receivepack = value;
188                 return 0;
189         } else if (!strcmp(name, TRANS_OPT_THIN)) {
190                 opts->thin = !!value;
191                 return 0;
192         } else if (!strcmp(name, TRANS_OPT_FOLLOWTAGS)) {
193                 opts->followtags = !!value;
194                 return 0;
195         } else if (!strcmp(name, TRANS_OPT_KEEP)) {
196                 opts->keep = !!value;
197                 return 0;
198         } else if (!strcmp(name, TRANS_OPT_UPDATE_SHALLOW)) {
199                 opts->update_shallow = !!value;
200                 return 0;
201         } else if (!strcmp(name, TRANS_OPT_DEPTH)) {
202                 if (!value)
203                         opts->depth = 0;
204                 else {
205                         char *end;
206                         opts->depth = strtol(value, &end, 0);
207                         if (*end)
208                                 die(_("transport: invalid depth option '%s'"), value);
209                 }
210                 return 0;
211         } else if (!strcmp(name, TRANS_OPT_DEEPEN_SINCE)) {
212                 opts->deepen_since = value;
213                 return 0;
214         } else if (!strcmp(name, TRANS_OPT_DEEPEN_NOT)) {
215                 opts->deepen_not = (const struct string_list *)value;
216                 return 0;
217         } else if (!strcmp(name, TRANS_OPT_DEEPEN_RELATIVE)) {
218                 opts->deepen_relative = !!value;
219                 return 0;
220         } else if (!strcmp(name, TRANS_OPT_FROM_PROMISOR)) {
221                 opts->from_promisor = !!value;
222                 return 0;
223         } else if (!strcmp(name, TRANS_OPT_NO_DEPENDENTS)) {
224                 opts->no_dependents = !!value;
225                 return 0;
226         } else if (!strcmp(name, TRANS_OPT_LIST_OBJECTS_FILTER)) {
227                 parse_list_objects_filter(&opts->filter_options, value);
228                 return 0;
229         }
230         return 1;
231 }
232
233 static int connect_setup(struct transport *transport, int for_push)
234 {
235         struct git_transport_data *data = transport->data;
236         int flags = transport->verbose > 0 ? CONNECT_VERBOSE : 0;
237
238         if (data->conn)
239                 return 0;
240
241         switch (transport->family) {
242         case TRANSPORT_FAMILY_ALL: break;
243         case TRANSPORT_FAMILY_IPV4: flags |= CONNECT_IPV4; break;
244         case TRANSPORT_FAMILY_IPV6: flags |= CONNECT_IPV6; break;
245         }
246
247         data->conn = git_connect(data->fd, transport->url,
248                                  for_push ? data->options.receivepack :
249                                  data->options.uploadpack,
250                                  flags);
251
252         return 0;
253 }
254
255 /*
256  * Obtains the protocol version from the transport and writes it to
257  * transport->data->version, first connecting if not already connected.
258  *
259  * If the protocol version is one that allows skipping the listing of remote
260  * refs, and must_list_refs is 0, the listing of remote refs is skipped and
261  * this function returns NULL. Otherwise, this function returns the list of
262  * remote refs.
263  */
264 static struct ref *handshake(struct transport *transport, int for_push,
265                              const struct argv_array *ref_prefixes,
266                              int must_list_refs)
267 {
268         struct git_transport_data *data = transport->data;
269         struct ref *refs = NULL;
270         struct packet_reader reader;
271
272         connect_setup(transport, for_push);
273
274         packet_reader_init(&reader, data->fd[0], NULL, 0,
275                            PACKET_READ_CHOMP_NEWLINE |
276                            PACKET_READ_GENTLE_ON_EOF);
277
278         data->version = discover_version(&reader);
279         switch (data->version) {
280         case protocol_v2:
281                 if (must_list_refs)
282                         get_remote_refs(data->fd[1], &reader, &refs, for_push,
283                                         ref_prefixes,
284                                         transport->server_options);
285                 break;
286         case protocol_v1:
287         case protocol_v0:
288                 get_remote_heads(&reader, &refs,
289                                  for_push ? REF_NORMAL : 0,
290                                  &data->extra_have,
291                                  &data->shallow);
292                 break;
293         case protocol_unknown_version:
294                 BUG("unknown protocol version");
295         }
296         data->got_remote_heads = 1;
297
298         if (reader.line_peeked)
299                 BUG("buffer must be empty at the end of handshake()");
300
301         return refs;
302 }
303
304 static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
305                                         const struct argv_array *ref_prefixes)
306 {
307         return handshake(transport, for_push, ref_prefixes, 1);
308 }
309
310 static int fetch_refs_via_pack(struct transport *transport,
311                                int nr_heads, struct ref **to_fetch)
312 {
313         int ret = 0;
314         struct git_transport_data *data = transport->data;
315         struct ref *refs = NULL;
316         char *dest = xstrdup(transport->url);
317         struct fetch_pack_args args;
318         struct ref *refs_tmp = NULL;
319
320         memset(&args, 0, sizeof(args));
321         args.uploadpack = data->options.uploadpack;
322         args.keep_pack = data->options.keep;
323         args.lock_pack = 1;
324         args.use_thin_pack = data->options.thin;
325         args.include_tag = data->options.followtags;
326         args.verbose = (transport->verbose > 1);
327         args.quiet = (transport->verbose < 0);
328         args.no_progress = !transport->progress;
329         args.depth = data->options.depth;
330         args.deepen_since = data->options.deepen_since;
331         args.deepen_not = data->options.deepen_not;
332         args.deepen_relative = data->options.deepen_relative;
333         args.check_self_contained_and_connected =
334                 data->options.check_self_contained_and_connected;
335         args.cloning = transport->cloning;
336         args.update_shallow = data->options.update_shallow;
337         args.from_promisor = data->options.from_promisor;
338         args.no_dependents = data->options.no_dependents;
339         args.filter_options = data->options.filter_options;
340         args.stateless_rpc = transport->stateless_rpc;
341         args.server_options = transport->server_options;
342         args.negotiation_tips = data->options.negotiation_tips;
343
344         if (!data->got_remote_heads) {
345                 int i;
346                 int must_list_refs = 0;
347                 for (i = 0; i < nr_heads; i++) {
348                         if (!to_fetch[i]->exact_oid) {
349                                 must_list_refs = 1;
350                                 break;
351                         }
352                 }
353                 refs_tmp = handshake(transport, 0, NULL, must_list_refs);
354         }
355
356         switch (data->version) {
357         case protocol_v2:
358                 refs = fetch_pack(&args, data->fd, data->conn,
359                                   refs_tmp ? refs_tmp : transport->remote_refs,
360                                   dest, to_fetch, nr_heads, &data->shallow,
361                                   &transport->pack_lockfile, data->version);
362                 break;
363         case protocol_v1:
364         case protocol_v0:
365                 refs = fetch_pack(&args, data->fd, data->conn,
366                                   refs_tmp ? refs_tmp : transport->remote_refs,
367                                   dest, to_fetch, nr_heads, &data->shallow,
368                                   &transport->pack_lockfile, data->version);
369                 break;
370         case protocol_unknown_version:
371                 BUG("unknown protocol version");
372         }
373
374         close(data->fd[0]);
375         close(data->fd[1]);
376         if (finish_connect(data->conn))
377                 ret = -1;
378         data->conn = NULL;
379         data->got_remote_heads = 0;
380         data->options.self_contained_and_connected =
381                 args.self_contained_and_connected;
382         data->options.connectivity_checked = args.connectivity_checked;
383
384         if (refs == NULL)
385                 ret = -1;
386         if (report_unmatched_refs(to_fetch, nr_heads))
387                 ret = -1;
388
389         free_refs(refs_tmp);
390         free_refs(refs);
391         free(dest);
392         return ret;
393 }
394
395 static int push_had_errors(struct ref *ref)
396 {
397         for (; ref; ref = ref->next) {
398                 switch (ref->status) {
399                 case REF_STATUS_NONE:
400                 case REF_STATUS_UPTODATE:
401                 case REF_STATUS_OK:
402                         break;
403                 default:
404                         return 1;
405                 }
406         }
407         return 0;
408 }
409
410 int transport_refs_pushed(struct ref *ref)
411 {
412         for (; ref; ref = ref->next) {
413                 switch(ref->status) {
414                 case REF_STATUS_NONE:
415                 case REF_STATUS_UPTODATE:
416                         break;
417                 default:
418                         return 1;
419                 }
420         }
421         return 0;
422 }
423
424 void transport_update_tracking_ref(struct remote *remote, struct ref *ref, int verbose)
425 {
426         struct refspec_item rs;
427
428         if (ref->status != REF_STATUS_OK && ref->status != REF_STATUS_UPTODATE)
429                 return;
430
431         rs.src = ref->name;
432         rs.dst = NULL;
433
434         if (!remote_find_tracking(remote, &rs)) {
435                 if (verbose)
436                         fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
437                 if (ref->deletion) {
438                         delete_ref(NULL, rs.dst, NULL, 0);
439                 } else
440                         update_ref("update by push", rs.dst, &ref->new_oid,
441                                    NULL, 0, 0);
442                 free(rs.dst);
443         }
444 }
445
446 static void print_ref_status(char flag, const char *summary,
447                              struct ref *to, struct ref *from, const char *msg,
448                              int porcelain, int summary_width)
449 {
450         if (porcelain) {
451                 if (from)
452                         fprintf(stdout, "%c\t%s:%s\t", flag, from->name, to->name);
453                 else
454                         fprintf(stdout, "%c\t:%s\t", flag, to->name);
455                 if (msg)
456                         fprintf(stdout, "%s (%s)\n", summary, msg);
457                 else
458                         fprintf(stdout, "%s\n", summary);
459         } else {
460                 const char *red = "", *reset = "";
461                 if (push_had_errors(to)) {
462                         red = transport_get_color(TRANSPORT_COLOR_REJECTED);
463                         reset = transport_get_color(TRANSPORT_COLOR_RESET);
464                 }
465                 fprintf(stderr, " %s%c %-*s%s ", red, flag, summary_width,
466                         summary, reset);
467                 if (from)
468                         fprintf(stderr, "%s -> %s", prettify_refname(from->name), prettify_refname(to->name));
469                 else
470                         fputs(prettify_refname(to->name), stderr);
471                 if (msg) {
472                         fputs(" (", stderr);
473                         fputs(msg, stderr);
474                         fputc(')', stderr);
475                 }
476                 fputc('\n', stderr);
477         }
478 }
479
480 static void print_ok_ref_status(struct ref *ref, int porcelain, int summary_width)
481 {
482         if (ref->deletion)
483                 print_ref_status('-', "[deleted]", ref, NULL, NULL,
484                                  porcelain, summary_width);
485         else if (is_null_oid(&ref->old_oid))
486                 print_ref_status('*',
487                         (starts_with(ref->name, "refs/tags/") ? "[new tag]" :
488                         "[new branch]"),
489                         ref, ref->peer_ref, NULL, porcelain, summary_width);
490         else {
491                 struct strbuf quickref = STRBUF_INIT;
492                 char type;
493                 const char *msg;
494
495                 strbuf_add_unique_abbrev(&quickref, &ref->old_oid,
496                                          DEFAULT_ABBREV);
497                 if (ref->forced_update) {
498                         strbuf_addstr(&quickref, "...");
499                         type = '+';
500                         msg = "forced update";
501                 } else {
502                         strbuf_addstr(&quickref, "..");
503                         type = ' ';
504                         msg = NULL;
505                 }
506                 strbuf_add_unique_abbrev(&quickref, &ref->new_oid,
507                                          DEFAULT_ABBREV);
508
509                 print_ref_status(type, quickref.buf, ref, ref->peer_ref, msg,
510                                  porcelain, summary_width);
511                 strbuf_release(&quickref);
512         }
513 }
514
515 static int print_one_push_status(struct ref *ref, const char *dest, int count,
516                                  int porcelain, int summary_width)
517 {
518         if (!count) {
519                 char *url = transport_anonymize_url(dest);
520                 fprintf(porcelain ? stdout : stderr, "To %s\n", url);
521                 free(url);
522         }
523
524         switch(ref->status) {
525         case REF_STATUS_NONE:
526                 print_ref_status('X', "[no match]", ref, NULL, NULL,
527                                  porcelain, summary_width);
528                 break;
529         case REF_STATUS_REJECT_NODELETE:
530                 print_ref_status('!', "[rejected]", ref, NULL,
531                                  "remote does not support deleting refs",
532                                  porcelain, summary_width);
533                 break;
534         case REF_STATUS_UPTODATE:
535                 print_ref_status('=', "[up to date]", ref,
536                                  ref->peer_ref, NULL, porcelain, summary_width);
537                 break;
538         case REF_STATUS_REJECT_NONFASTFORWARD:
539                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
540                                  "non-fast-forward", porcelain, summary_width);
541                 break;
542         case REF_STATUS_REJECT_ALREADY_EXISTS:
543                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
544                                  "already exists", porcelain, summary_width);
545                 break;
546         case REF_STATUS_REJECT_FETCH_FIRST:
547                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
548                                  "fetch first", porcelain, summary_width);
549                 break;
550         case REF_STATUS_REJECT_NEEDS_FORCE:
551                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
552                                  "needs force", porcelain, summary_width);
553                 break;
554         case REF_STATUS_REJECT_STALE:
555                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
556                                  "stale info", porcelain, summary_width);
557                 break;
558         case REF_STATUS_REJECT_SHALLOW:
559                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
560                                  "new shallow roots not allowed",
561                                  porcelain, summary_width);
562                 break;
563         case REF_STATUS_REMOTE_REJECT:
564                 print_ref_status('!', "[remote rejected]", ref,
565                                  ref->deletion ? NULL : ref->peer_ref,
566                                  ref->remote_status, porcelain, summary_width);
567                 break;
568         case REF_STATUS_EXPECTING_REPORT:
569                 print_ref_status('!', "[remote failure]", ref,
570                                  ref->deletion ? NULL : ref->peer_ref,
571                                  "remote failed to report status",
572                                  porcelain, summary_width);
573                 break;
574         case REF_STATUS_ATOMIC_PUSH_FAILED:
575                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
576                                  "atomic push failed", porcelain, summary_width);
577                 break;
578         case REF_STATUS_OK:
579                 print_ok_ref_status(ref, porcelain, summary_width);
580                 break;
581         }
582
583         return 1;
584 }
585
586 static int measure_abbrev(const struct object_id *oid, int sofar)
587 {
588         char hex[GIT_MAX_HEXSZ + 1];
589         int w = find_unique_abbrev_r(hex, oid, DEFAULT_ABBREV);
590
591         return (w < sofar) ? sofar : w;
592 }
593
594 int transport_summary_width(const struct ref *refs)
595 {
596         int maxw = -1;
597
598         for (; refs; refs = refs->next) {
599                 maxw = measure_abbrev(&refs->old_oid, maxw);
600                 maxw = measure_abbrev(&refs->new_oid, maxw);
601         }
602         if (maxw < 0)
603                 maxw = FALLBACK_DEFAULT_ABBREV;
604         return (2 * maxw + 3);
605 }
606
607 void transport_print_push_status(const char *dest, struct ref *refs,
608                                   int verbose, int porcelain, unsigned int *reject_reasons)
609 {
610         struct ref *ref;
611         int n = 0;
612         char *head;
613         int summary_width = transport_summary_width(refs);
614
615         if (transport_color_config() < 0)
616                 warning(_("could not parse transport.color.* config"));
617
618         head = resolve_refdup("HEAD", RESOLVE_REF_READING, NULL, NULL);
619
620         if (verbose) {
621                 for (ref = refs; ref; ref = ref->next)
622                         if (ref->status == REF_STATUS_UPTODATE)
623                                 n += print_one_push_status(ref, dest, n,
624                                                            porcelain, summary_width);
625         }
626
627         for (ref = refs; ref; ref = ref->next)
628                 if (ref->status == REF_STATUS_OK)
629                         n += print_one_push_status(ref, dest, n,
630                                                    porcelain, summary_width);
631
632         *reject_reasons = 0;
633         for (ref = refs; ref; ref = ref->next) {
634                 if (ref->status != REF_STATUS_NONE &&
635                     ref->status != REF_STATUS_UPTODATE &&
636                     ref->status != REF_STATUS_OK)
637                         n += print_one_push_status(ref, dest, n,
638                                                    porcelain, summary_width);
639                 if (ref->status == REF_STATUS_REJECT_NONFASTFORWARD) {
640                         if (head != NULL && !strcmp(head, ref->name))
641                                 *reject_reasons |= REJECT_NON_FF_HEAD;
642                         else
643                                 *reject_reasons |= REJECT_NON_FF_OTHER;
644                 } else if (ref->status == REF_STATUS_REJECT_ALREADY_EXISTS) {
645                         *reject_reasons |= REJECT_ALREADY_EXISTS;
646                 } else if (ref->status == REF_STATUS_REJECT_FETCH_FIRST) {
647                         *reject_reasons |= REJECT_FETCH_FIRST;
648                 } else if (ref->status == REF_STATUS_REJECT_NEEDS_FORCE) {
649                         *reject_reasons |= REJECT_NEEDS_FORCE;
650                 }
651         }
652         free(head);
653 }
654
655 static int git_transport_push(struct transport *transport, struct ref *remote_refs, int flags)
656 {
657         struct git_transport_data *data = transport->data;
658         struct send_pack_args args;
659         int ret = 0;
660
661         if (transport_color_config() < 0)
662                 return -1;
663
664         if (!data->got_remote_heads)
665                 get_refs_via_connect(transport, 1, NULL);
666
667         memset(&args, 0, sizeof(args));
668         args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
669         args.force_update = !!(flags & TRANSPORT_PUSH_FORCE);
670         args.use_thin_pack = data->options.thin;
671         args.verbose = (transport->verbose > 0);
672         args.quiet = (transport->verbose < 0);
673         args.progress = transport->progress;
674         args.dry_run = !!(flags & TRANSPORT_PUSH_DRY_RUN);
675         args.porcelain = !!(flags & TRANSPORT_PUSH_PORCELAIN);
676         args.atomic = !!(flags & TRANSPORT_PUSH_ATOMIC);
677         args.push_options = transport->push_options;
678         args.url = transport->url;
679
680         if (flags & TRANSPORT_PUSH_CERT_ALWAYS)
681                 args.push_cert = SEND_PACK_PUSH_CERT_ALWAYS;
682         else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED)
683                 args.push_cert = SEND_PACK_PUSH_CERT_IF_ASKED;
684         else
685                 args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
686
687         switch (data->version) {
688         case protocol_v2:
689                 die(_("support for protocol v2 not implemented yet"));
690                 break;
691         case protocol_v1:
692         case protocol_v0:
693                 ret = send_pack(&args, data->fd, data->conn, remote_refs,
694                                 &data->extra_have);
695                 break;
696         case protocol_unknown_version:
697                 BUG("unknown protocol version");
698         }
699
700         close(data->fd[1]);
701         close(data->fd[0]);
702         ret |= finish_connect(data->conn);
703         data->conn = NULL;
704         data->got_remote_heads = 0;
705
706         return ret;
707 }
708
709 static int connect_git(struct transport *transport, const char *name,
710                        const char *executable, int fd[2])
711 {
712         struct git_transport_data *data = transport->data;
713         data->conn = git_connect(data->fd, transport->url,
714                                  executable, 0);
715         fd[0] = data->fd[0];
716         fd[1] = data->fd[1];
717         return 0;
718 }
719
720 static int disconnect_git(struct transport *transport)
721 {
722         struct git_transport_data *data = transport->data;
723         if (data->conn) {
724                 if (data->got_remote_heads)
725                         packet_flush(data->fd[1]);
726                 close(data->fd[0]);
727                 close(data->fd[1]);
728                 finish_connect(data->conn);
729         }
730
731         free(data);
732         return 0;
733 }
734
735 static struct transport_vtable taken_over_vtable = {
736         1,
737         NULL,
738         get_refs_via_connect,
739         fetch_refs_via_pack,
740         git_transport_push,
741         NULL,
742         disconnect_git
743 };
744
745 void transport_take_over(struct transport *transport,
746                          struct child_process *child)
747 {
748         struct git_transport_data *data;
749
750         if (!transport->smart_options)
751                 BUG("taking over transport requires non-NULL "
752                     "smart_options field.");
753
754         data = xcalloc(1, sizeof(*data));
755         data->options = *transport->smart_options;
756         data->conn = child;
757         data->fd[0] = data->conn->out;
758         data->fd[1] = data->conn->in;
759         data->got_remote_heads = 0;
760         transport->data = data;
761
762         transport->vtable = &taken_over_vtable;
763         transport->smart_options = &(data->options);
764
765         transport->cannot_reuse = 1;
766 }
767
768 static int is_file(const char *url)
769 {
770         struct stat buf;
771         if (stat(url, &buf))
772                 return 0;
773         return S_ISREG(buf.st_mode);
774 }
775
776 static int external_specification_len(const char *url)
777 {
778         return strchr(url, ':') - url;
779 }
780
781 static const struct string_list *protocol_whitelist(void)
782 {
783         static int enabled = -1;
784         static struct string_list allowed = STRING_LIST_INIT_DUP;
785
786         if (enabled < 0) {
787                 const char *v = getenv("GIT_ALLOW_PROTOCOL");
788                 if (v) {
789                         string_list_split(&allowed, v, ':', -1);
790                         string_list_sort(&allowed);
791                         enabled = 1;
792                 } else {
793                         enabled = 0;
794                 }
795         }
796
797         return enabled ? &allowed : NULL;
798 }
799
800 enum protocol_allow_config {
801         PROTOCOL_ALLOW_NEVER = 0,
802         PROTOCOL_ALLOW_USER_ONLY,
803         PROTOCOL_ALLOW_ALWAYS
804 };
805
806 static enum protocol_allow_config parse_protocol_config(const char *key,
807                                                         const char *value)
808 {
809         if (!strcasecmp(value, "always"))
810                 return PROTOCOL_ALLOW_ALWAYS;
811         else if (!strcasecmp(value, "never"))
812                 return PROTOCOL_ALLOW_NEVER;
813         else if (!strcasecmp(value, "user"))
814                 return PROTOCOL_ALLOW_USER_ONLY;
815
816         die(_("unknown value for config '%s': %s"), key, value);
817 }
818
819 static enum protocol_allow_config get_protocol_config(const char *type)
820 {
821         char *key = xstrfmt("protocol.%s.allow", type);
822         char *value;
823
824         /* first check the per-protocol config */
825         if (!git_config_get_string(key, &value)) {
826                 enum protocol_allow_config ret =
827                         parse_protocol_config(key, value);
828                 free(key);
829                 free(value);
830                 return ret;
831         }
832         free(key);
833
834         /* if defined, fallback to user-defined default for unknown protocols */
835         if (!git_config_get_string("protocol.allow", &value)) {
836                 enum protocol_allow_config ret =
837                         parse_protocol_config("protocol.allow", value);
838                 free(value);
839                 return ret;
840         }
841
842         /* fallback to built-in defaults */
843         /* known safe */
844         if (!strcmp(type, "http") ||
845             !strcmp(type, "https") ||
846             !strcmp(type, "git") ||
847             !strcmp(type, "ssh") ||
848             !strcmp(type, "file"))
849                 return PROTOCOL_ALLOW_ALWAYS;
850
851         /* known scary; err on the side of caution */
852         if (!strcmp(type, "ext"))
853                 return PROTOCOL_ALLOW_NEVER;
854
855         /* unknown; by default let them be used only directly by the user */
856         return PROTOCOL_ALLOW_USER_ONLY;
857 }
858
859 int is_transport_allowed(const char *type, int from_user)
860 {
861         const struct string_list *whitelist = protocol_whitelist();
862         if (whitelist)
863                 return string_list_has_string(whitelist, type);
864
865         switch (get_protocol_config(type)) {
866         case PROTOCOL_ALLOW_ALWAYS:
867                 return 1;
868         case PROTOCOL_ALLOW_NEVER:
869                 return 0;
870         case PROTOCOL_ALLOW_USER_ONLY:
871                 if (from_user < 0)
872                         from_user = git_env_bool("GIT_PROTOCOL_FROM_USER", 1);
873                 return from_user;
874         }
875
876         BUG("invalid protocol_allow_config type");
877 }
878
879 void transport_check_allowed(const char *type)
880 {
881         if (!is_transport_allowed(type, -1))
882                 die(_("transport '%s' not allowed"), type);
883 }
884
885 static struct transport_vtable bundle_vtable = {
886         0,
887         NULL,
888         get_refs_from_bundle,
889         fetch_refs_from_bundle,
890         NULL,
891         NULL,
892         close_bundle
893 };
894
895 static struct transport_vtable builtin_smart_vtable = {
896         1,
897         NULL,
898         get_refs_via_connect,
899         fetch_refs_via_pack,
900         git_transport_push,
901         connect_git,
902         disconnect_git
903 };
904
905 struct transport *transport_get(struct remote *remote, const char *url)
906 {
907         const char *helper;
908         struct transport *ret = xcalloc(1, sizeof(*ret));
909
910         ret->progress = isatty(2);
911
912         if (!remote)
913                 BUG("No remote provided to transport_get()");
914
915         ret->got_remote_refs = 0;
916         ret->remote = remote;
917         helper = remote->foreign_vcs;
918
919         if (!url && remote->url)
920                 url = remote->url[0];
921         ret->url = url;
922
923         /* maybe it is a foreign URL? */
924         if (url) {
925                 const char *p = url;
926
927                 while (is_urlschemechar(p == url, *p))
928                         p++;
929                 if (starts_with(p, "::"))
930                         helper = xstrndup(url, p - url);
931         }
932
933         if (helper) {
934                 transport_helper_init(ret, helper);
935         } else if (starts_with(url, "rsync:")) {
936                 die(_("git-over-rsync is no longer supported"));
937         } else if (url_is_local_not_ssh(url) && is_file(url) && is_bundle(url, 1)) {
938                 struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
939                 transport_check_allowed("file");
940                 ret->data = data;
941                 ret->vtable = &bundle_vtable;
942                 ret->smart_options = NULL;
943         } else if (!is_url(url)
944                 || starts_with(url, "file://")
945                 || starts_with(url, "git://")
946                 || starts_with(url, "ssh://")
947                 || starts_with(url, "git+ssh://") /* deprecated - do not use */
948                 || starts_with(url, "ssh+git://") /* deprecated - do not use */
949                 ) {
950                 /*
951                  * These are builtin smart transports; "allowed" transports
952                  * will be checked individually in git_connect.
953                  */
954                 struct git_transport_data *data = xcalloc(1, sizeof(*data));
955                 ret->data = data;
956                 ret->vtable = &builtin_smart_vtable;
957                 ret->smart_options = &(data->options);
958
959                 data->conn = NULL;
960                 data->got_remote_heads = 0;
961         } else {
962                 /* Unknown protocol in URL. Pass to external handler. */
963                 int len = external_specification_len(url);
964                 char *handler = xmemdupz(url, len);
965                 transport_helper_init(ret, handler);
966         }
967
968         if (ret->smart_options) {
969                 ret->smart_options->thin = 1;
970                 ret->smart_options->uploadpack = "git-upload-pack";
971                 if (remote->uploadpack)
972                         ret->smart_options->uploadpack = remote->uploadpack;
973                 ret->smart_options->receivepack = "git-receive-pack";
974                 if (remote->receivepack)
975                         ret->smart_options->receivepack = remote->receivepack;
976         }
977
978         return ret;
979 }
980
981 int transport_set_option(struct transport *transport,
982                          const char *name, const char *value)
983 {
984         int git_reports = 1, protocol_reports = 1;
985
986         if (transport->smart_options)
987                 git_reports = set_git_option(transport->smart_options,
988                                              name, value);
989
990         if (transport->vtable->set_option)
991                 protocol_reports = transport->vtable->set_option(transport,
992                                                                  name, value);
993
994         /* If either report is 0, report 0 (success). */
995         if (!git_reports || !protocol_reports)
996                 return 0;
997         /* If either reports -1 (invalid value), report -1. */
998         if ((git_reports == -1) || (protocol_reports == -1))
999                 return -1;
1000         /* Otherwise if both report unknown, report unknown. */
1001         return 1;
1002 }
1003
1004 void transport_set_verbosity(struct transport *transport, int verbosity,
1005         int force_progress)
1006 {
1007         if (verbosity >= 1)
1008                 transport->verbose = verbosity <= 3 ? verbosity : 3;
1009         if (verbosity < 0)
1010                 transport->verbose = -1;
1011
1012         /**
1013          * Rules used to determine whether to report progress (processing aborts
1014          * when a rule is satisfied):
1015          *
1016          *   . Report progress, if force_progress is 1 (ie. --progress).
1017          *   . Don't report progress, if force_progress is 0 (ie. --no-progress).
1018          *   . Don't report progress, if verbosity < 0 (ie. -q/--quiet ).
1019          *   . Report progress if isatty(2) is 1.
1020          **/
1021         if (force_progress >= 0)
1022                 transport->progress = !!force_progress;
1023         else
1024                 transport->progress = verbosity >= 0 && isatty(2);
1025 }
1026
1027 static void die_with_unpushed_submodules(struct string_list *needs_pushing)
1028 {
1029         int i;
1030
1031         fprintf(stderr, _("The following submodule paths contain changes that can\n"
1032                         "not be found on any remote:\n"));
1033         for (i = 0; i < needs_pushing->nr; i++)
1034                 fprintf(stderr, "  %s\n", needs_pushing->items[i].string);
1035         fprintf(stderr, _("\nPlease try\n\n"
1036                           "     git push --recurse-submodules=on-demand\n\n"
1037                           "or cd to the path and use\n\n"
1038                           "     git push\n\n"
1039                           "to push them to a remote.\n\n"));
1040
1041         string_list_clear(needs_pushing, 0);
1042
1043         die(_("Aborting."));
1044 }
1045
1046 static int run_pre_push_hook(struct transport *transport,
1047                              struct ref *remote_refs)
1048 {
1049         int ret = 0, x;
1050         struct ref *r;
1051         struct child_process proc = CHILD_PROCESS_INIT;
1052         struct strbuf buf;
1053         const char *argv[4];
1054
1055         if (!(argv[0] = find_hook("pre-push")))
1056                 return 0;
1057
1058         argv[1] = transport->remote->name;
1059         argv[2] = transport->url;
1060         argv[3] = NULL;
1061
1062         proc.argv = argv;
1063         proc.in = -1;
1064
1065         if (start_command(&proc)) {
1066                 finish_command(&proc);
1067                 return -1;
1068         }
1069
1070         sigchain_push(SIGPIPE, SIG_IGN);
1071
1072         strbuf_init(&buf, 256);
1073
1074         for (r = remote_refs; r; r = r->next) {
1075                 if (!r->peer_ref) continue;
1076                 if (r->status == REF_STATUS_REJECT_NONFASTFORWARD) continue;
1077                 if (r->status == REF_STATUS_REJECT_STALE) continue;
1078                 if (r->status == REF_STATUS_UPTODATE) continue;
1079
1080                 strbuf_reset(&buf);
1081                 strbuf_addf( &buf, "%s %s %s %s\n",
1082                          r->peer_ref->name, oid_to_hex(&r->new_oid),
1083                          r->name, oid_to_hex(&r->old_oid));
1084
1085                 if (write_in_full(proc.in, buf.buf, buf.len) < 0) {
1086                         /* We do not mind if a hook does not read all refs. */
1087                         if (errno != EPIPE)
1088                                 ret = -1;
1089                         break;
1090                 }
1091         }
1092
1093         strbuf_release(&buf);
1094
1095         x = close(proc.in);
1096         if (!ret)
1097                 ret = x;
1098
1099         sigchain_pop(SIGPIPE);
1100
1101         x = finish_command(&proc);
1102         if (!ret)
1103                 ret = x;
1104
1105         return ret;
1106 }
1107
1108 int transport_push(struct transport *transport,
1109                    struct refspec *rs, int flags,
1110                    unsigned int *reject_reasons)
1111 {
1112         *reject_reasons = 0;
1113
1114         if (transport_color_config() < 0)
1115                 return -1;
1116
1117         if (transport->vtable->push_refs) {
1118                 struct ref *remote_refs;
1119                 struct ref *local_refs = get_local_heads();
1120                 int match_flags = MATCH_REFS_NONE;
1121                 int verbose = (transport->verbose > 0);
1122                 int quiet = (transport->verbose < 0);
1123                 int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
1124                 int pretend = flags & TRANSPORT_PUSH_DRY_RUN;
1125                 int push_ret, ret, err;
1126                 struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
1127
1128                 if (check_push_refs(local_refs, rs) < 0)
1129                         return -1;
1130
1131                 refspec_ref_prefixes(rs, &ref_prefixes);
1132
1133                 remote_refs = transport->vtable->get_refs_list(transport, 1,
1134                                                                &ref_prefixes);
1135
1136                 argv_array_clear(&ref_prefixes);
1137
1138                 if (flags & TRANSPORT_PUSH_ALL)
1139                         match_flags |= MATCH_REFS_ALL;
1140                 if (flags & TRANSPORT_PUSH_MIRROR)
1141                         match_flags |= MATCH_REFS_MIRROR;
1142                 if (flags & TRANSPORT_PUSH_PRUNE)
1143                         match_flags |= MATCH_REFS_PRUNE;
1144                 if (flags & TRANSPORT_PUSH_FOLLOW_TAGS)
1145                         match_flags |= MATCH_REFS_FOLLOW_TAGS;
1146
1147                 if (match_push_refs(local_refs, &remote_refs, rs, match_flags))
1148                         return -1;
1149
1150                 if (transport->smart_options &&
1151                     transport->smart_options->cas &&
1152                     !is_empty_cas(transport->smart_options->cas))
1153                         apply_push_cas(transport->smart_options->cas,
1154                                        transport->remote, remote_refs);
1155
1156                 set_ref_status_for_push(remote_refs,
1157                         flags & TRANSPORT_PUSH_MIRROR,
1158                         flags & TRANSPORT_PUSH_FORCE);
1159
1160                 if (!(flags & TRANSPORT_PUSH_NO_HOOK))
1161                         if (run_pre_push_hook(transport, remote_refs))
1162                                 return -1;
1163
1164                 if ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
1165                               TRANSPORT_RECURSE_SUBMODULES_ONLY)) &&
1166                     !is_bare_repository()) {
1167                         struct ref *ref = remote_refs;
1168                         struct oid_array commits = OID_ARRAY_INIT;
1169
1170                         for (; ref; ref = ref->next)
1171                                 if (!is_null_oid(&ref->new_oid))
1172                                         oid_array_append(&commits,
1173                                                           &ref->new_oid);
1174
1175                         if (!push_unpushed_submodules(the_repository,
1176                                                       &commits,
1177                                                       transport->remote,
1178                                                       rs,
1179                                                       transport->push_options,
1180                                                       pretend)) {
1181                                 oid_array_clear(&commits);
1182                                 die(_("failed to push all needed submodules"));
1183                         }
1184                         oid_array_clear(&commits);
1185                 }
1186
1187                 if (((flags & TRANSPORT_RECURSE_SUBMODULES_CHECK) ||
1188                      ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
1189                                 TRANSPORT_RECURSE_SUBMODULES_ONLY)) &&
1190                       !pretend)) && !is_bare_repository()) {
1191                         struct ref *ref = remote_refs;
1192                         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1193                         struct oid_array commits = OID_ARRAY_INIT;
1194
1195                         for (; ref; ref = ref->next)
1196                                 if (!is_null_oid(&ref->new_oid))
1197                                         oid_array_append(&commits,
1198                                                           &ref->new_oid);
1199
1200                         if (find_unpushed_submodules(the_repository,
1201                                                      &commits,
1202                                                      transport->remote->name,
1203                                                      &needs_pushing)) {
1204                                 oid_array_clear(&commits);
1205                                 die_with_unpushed_submodules(&needs_pushing);
1206                         }
1207                         string_list_clear(&needs_pushing, 0);
1208                         oid_array_clear(&commits);
1209                 }
1210
1211                 if (!(flags & TRANSPORT_RECURSE_SUBMODULES_ONLY))
1212                         push_ret = transport->vtable->push_refs(transport, remote_refs, flags);
1213                 else
1214                         push_ret = 0;
1215                 err = push_had_errors(remote_refs);
1216                 ret = push_ret | err;
1217
1218                 if (!quiet || err)
1219                         transport_print_push_status(transport->url, remote_refs,
1220                                         verbose | porcelain, porcelain,
1221                                         reject_reasons);
1222
1223                 if (flags & TRANSPORT_PUSH_SET_UPSTREAM)
1224                         set_upstreams(transport, remote_refs, pretend);
1225
1226                 if (!(flags & (TRANSPORT_PUSH_DRY_RUN |
1227                                TRANSPORT_RECURSE_SUBMODULES_ONLY))) {
1228                         struct ref *ref;
1229                         for (ref = remote_refs; ref; ref = ref->next)
1230                                 transport_update_tracking_ref(transport->remote, ref, verbose);
1231                 }
1232
1233                 if (porcelain && !push_ret)
1234                         puts("Done");
1235                 else if (!quiet && !ret && !transport_refs_pushed(remote_refs))
1236                         fprintf(stderr, "Everything up-to-date\n");
1237
1238                 return ret;
1239         }
1240         return 1;
1241 }
1242
1243 const struct ref *transport_get_remote_refs(struct transport *transport,
1244                                             const struct argv_array *ref_prefixes)
1245 {
1246         if (!transport->got_remote_refs) {
1247                 transport->remote_refs =
1248                         transport->vtable->get_refs_list(transport, 0,
1249                                                          ref_prefixes);
1250                 transport->got_remote_refs = 1;
1251         }
1252
1253         return transport->remote_refs;
1254 }
1255
1256 int transport_fetch_refs(struct transport *transport, struct ref *refs)
1257 {
1258         int rc;
1259         int nr_heads = 0, nr_alloc = 0, nr_refs = 0;
1260         struct ref **heads = NULL;
1261         struct ref *rm;
1262
1263         if (!transport->vtable->fetch_without_list)
1264                 /*
1265                  * Some transports (e.g. the built-in bundle transport and the
1266                  * transport helper interface) do not work when fetching is
1267                  * done immediately after transport creation. List the remote
1268                  * refs anyway (if not already listed) as a workaround.
1269                  */
1270                 transport_get_remote_refs(transport, NULL);
1271
1272         for (rm = refs; rm; rm = rm->next) {
1273                 nr_refs++;
1274                 if (rm->peer_ref &&
1275                     !is_null_oid(&rm->old_oid) &&
1276                     oideq(&rm->peer_ref->old_oid, &rm->old_oid))
1277                         continue;
1278                 ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
1279                 heads[nr_heads++] = rm;
1280         }
1281
1282         if (!nr_heads) {
1283                 /*
1284                  * When deepening of a shallow repository is requested,
1285                  * then local and remote refs are likely to still be equal.
1286                  * Just feed them all to the fetch method in that case.
1287                  * This condition shouldn't be met in a non-deepening fetch
1288                  * (see builtin/fetch.c:quickfetch()).
1289                  */
1290                 ALLOC_ARRAY(heads, nr_refs);
1291                 for (rm = refs; rm; rm = rm->next)
1292                         heads[nr_heads++] = rm;
1293         }
1294
1295         rc = transport->vtable->fetch(transport, nr_heads, heads);
1296
1297         free(heads);
1298         return rc;
1299 }
1300
1301 void transport_unlock_pack(struct transport *transport)
1302 {
1303         if (transport->pack_lockfile) {
1304                 unlink_or_warn(transport->pack_lockfile);
1305                 FREE_AND_NULL(transport->pack_lockfile);
1306         }
1307 }
1308
1309 int transport_connect(struct transport *transport, const char *name,
1310                       const char *exec, int fd[2])
1311 {
1312         if (transport->vtable->connect)
1313                 return transport->vtable->connect(transport, name, exec, fd);
1314         else
1315                 die(_("operation not supported by protocol"));
1316 }
1317
1318 int transport_disconnect(struct transport *transport)
1319 {
1320         int ret = 0;
1321         if (transport->vtable->disconnect)
1322                 ret = transport->vtable->disconnect(transport);
1323         free(transport);
1324         return ret;
1325 }
1326
1327 /*
1328  * Strip username (and password) from a URL and return
1329  * it in a newly allocated string.
1330  */
1331 char *transport_anonymize_url(const char *url)
1332 {
1333         char *scheme_prefix, *anon_part;
1334         size_t anon_len, prefix_len = 0;
1335
1336         anon_part = strchr(url, '@');
1337         if (url_is_local_not_ssh(url) || !anon_part)
1338                 goto literal_copy;
1339
1340         anon_len = strlen(++anon_part);
1341         scheme_prefix = strstr(url, "://");
1342         if (!scheme_prefix) {
1343                 if (!strchr(anon_part, ':'))
1344                         /* cannot be "me@there:/path/name" */
1345                         goto literal_copy;
1346         } else {
1347                 const char *cp;
1348                 /* make sure scheme is reasonable */
1349                 for (cp = url; cp < scheme_prefix; cp++) {
1350                         switch (*cp) {
1351                                 /* RFC 1738 2.1 */
1352                         case '+': case '.': case '-':
1353                                 break; /* ok */
1354                         default:
1355                                 if (isalnum(*cp))
1356                                         break;
1357                                 /* it isn't */
1358                                 goto literal_copy;
1359                         }
1360                 }
1361                 /* @ past the first slash does not count */
1362                 cp = strchr(scheme_prefix + 3, '/');
1363                 if (cp && cp < anon_part)
1364                         goto literal_copy;
1365                 prefix_len = scheme_prefix - url + 3;
1366         }
1367         return xstrfmt("%.*s%.*s", (int)prefix_len, url,
1368                        (int)anon_len, anon_part);
1369 literal_copy:
1370         return xstrdup(url);
1371 }
1372
1373 static void fill_alternate_refs_command(struct child_process *cmd,
1374                                         const char *repo_path)
1375 {
1376         const char *value;
1377
1378         if (!git_config_get_value("core.alternateRefsCommand", &value)) {
1379                 cmd->use_shell = 1;
1380
1381                 argv_array_push(&cmd->args, value);
1382                 argv_array_push(&cmd->args, repo_path);
1383         } else {
1384                 cmd->git_cmd = 1;
1385
1386                 argv_array_pushf(&cmd->args, "--git-dir=%s", repo_path);
1387                 argv_array_push(&cmd->args, "for-each-ref");
1388                 argv_array_push(&cmd->args, "--format=%(objectname)");
1389
1390                 if (!git_config_get_value("core.alternateRefsPrefixes", &value)) {
1391                         argv_array_push(&cmd->args, "--");
1392                         argv_array_split(&cmd->args, value);
1393                 }
1394         }
1395
1396         cmd->env = local_repo_env;
1397         cmd->out = -1;
1398 }
1399
1400 static void read_alternate_refs(const char *path,
1401                                 alternate_ref_fn *cb,
1402                                 void *data)
1403 {
1404         struct child_process cmd = CHILD_PROCESS_INIT;
1405         struct strbuf line = STRBUF_INIT;
1406         FILE *fh;
1407
1408         fill_alternate_refs_command(&cmd, path);
1409
1410         if (start_command(&cmd))
1411                 return;
1412
1413         fh = xfdopen(cmd.out, "r");
1414         while (strbuf_getline_lf(&line, fh) != EOF) {
1415                 struct object_id oid;
1416                 const char *p;
1417
1418                 if (parse_oid_hex(line.buf, &oid, &p) || *p) {
1419                         warning(_("invalid line while parsing alternate refs: %s"),
1420                                 line.buf);
1421                         break;
1422                 }
1423
1424                 cb(&oid, data);
1425         }
1426
1427         fclose(fh);
1428         finish_command(&cmd);
1429 }
1430
1431 struct alternate_refs_data {
1432         alternate_ref_fn *fn;
1433         void *data;
1434 };
1435
1436 static int refs_from_alternate_cb(struct alternate_object_database *e,
1437                                   void *data)
1438 {
1439         struct strbuf path = STRBUF_INIT;
1440         size_t base_len;
1441         struct alternate_refs_data *cb = data;
1442
1443         if (!strbuf_realpath(&path, e->path, 0))
1444                 goto out;
1445         if (!strbuf_strip_suffix(&path, "/objects"))
1446                 goto out;
1447         base_len = path.len;
1448
1449         /* Is this a git repository with refs? */
1450         strbuf_addstr(&path, "/refs");
1451         if (!is_directory(path.buf))
1452                 goto out;
1453         strbuf_setlen(&path, base_len);
1454
1455         read_alternate_refs(path.buf, cb->fn, cb->data);
1456
1457 out:
1458         strbuf_release(&path);
1459         return 0;
1460 }
1461
1462 void for_each_alternate_ref(alternate_ref_fn fn, void *data)
1463 {
1464         struct alternate_refs_data cb;
1465         cb.fn = fn;
1466         cb.data = data;
1467         foreach_alt_odb(refs_from_alternate_cb, &cb);
1468 }