branch: implement '--format' option
[git] / ref-filter.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "parse-options.h"
4 #include "refs.h"
5 #include "wildmatch.h"
6 #include "commit.h"
7 #include "remote.h"
8 #include "color.h"
9 #include "tag.h"
10 #include "quote.h"
11 #include "ref-filter.h"
12 #include "revision.h"
13 #include "utf8.h"
14 #include "git-compat-util.h"
15 #include "version.h"
16 #include "trailer.h"
17 #include "wt-status.h"
18
19 static struct ref_msg {
20         const char *gone;
21         const char *ahead;
22         const char *behind;
23         const char *ahead_behind;
24 } msgs = {
25          /* Untranslated plumbing messages: */
26         "gone",
27         "ahead %d",
28         "behind %d",
29         "ahead %d, behind %d"
30 };
31
32 void setup_ref_filter_porcelain_msg(void)
33 {
34         msgs.gone = _("gone");
35         msgs.ahead = _("ahead %d");
36         msgs.behind = _("behind %d");
37         msgs.ahead_behind = _("ahead %d, behind %d");
38 }
39
40 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
41 typedef enum { COMPARE_EQUAL, COMPARE_UNEQUAL, COMPARE_NONE } cmp_status;
42
43 struct align {
44         align_type position;
45         unsigned int width;
46 };
47
48 struct if_then_else {
49         cmp_status cmp_status;
50         const char *str;
51         unsigned int then_atom_seen : 1,
52                 else_atom_seen : 1,
53                 condition_satisfied : 1;
54 };
55
56 struct refname_atom {
57         enum { R_NORMAL, R_SHORT, R_LSTRIP, R_RSTRIP } option;
58         int lstrip, rstrip;
59 };
60
61 /*
62  * An atom is a valid field atom listed below, possibly prefixed with
63  * a "*" to denote deref_tag().
64  *
65  * We parse given format string and sort specifiers, and make a list
66  * of properties that we need to extract out of objects.  ref_array_item
67  * structure will hold an array of values extracted that can be
68  * indexed with the "atom number", which is an index into this
69  * array.
70  */
71 static struct used_atom {
72         const char *name;
73         cmp_type type;
74         union {
75                 char color[COLOR_MAXLEN];
76                 struct align align;
77                 struct {
78                         enum { RR_REF, RR_TRACK, RR_TRACKSHORT } option;
79                         struct refname_atom refname;
80                         unsigned int nobracket : 1;
81                 } remote_ref;
82                 struct {
83                         enum { C_BARE, C_BODY, C_BODY_DEP, C_LINES, C_SIG, C_SUB, C_TRAILERS } option;
84                         unsigned int nlines;
85                 } contents;
86                 struct {
87                         cmp_status cmp_status;
88                         const char *str;
89                 } if_then_else;
90                 struct {
91                         enum { O_FULL, O_LENGTH, O_SHORT } option;
92                         unsigned int length;
93                 } objectname;
94                 struct refname_atom refname;
95         } u;
96 } *used_atom;
97 static int used_atom_cnt, need_tagged, need_symref;
98 static int need_color_reset_at_eol;
99
100 static void color_atom_parser(struct used_atom *atom, const char *color_value)
101 {
102         if (!color_value)
103                 die(_("expected format: %%(color:<color>)"));
104         if (color_parse(color_value, atom->u.color) < 0)
105                 die(_("unrecognized color: %%(color:%s)"), color_value);
106 }
107
108 static void refname_atom_parser_internal(struct refname_atom *atom,
109                                          const char *arg, const char *name)
110 {
111         if (!arg)
112                 atom->option = R_NORMAL;
113         else if (!strcmp(arg, "short"))
114                 atom->option = R_SHORT;
115         else if (skip_prefix(arg, "lstrip=", &arg)) {
116                 atom->option = R_LSTRIP;
117                 if (strtol_i(arg, 10, &atom->lstrip))
118                         die(_("Integer value expected refname:lstrip=%s"), arg);
119         } else if (skip_prefix(arg, "rstrip=", &arg)) {
120                 atom->option = R_RSTRIP;
121                 if (strtol_i(arg, 10, &atom->rstrip))
122                         die(_("Integer value expected refname:rstrip=%s"), arg);
123         } else
124                 die(_("unrecognized %%(%s) argument: %s"), name, arg);
125 }
126
127 static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
128 {
129         struct string_list params = STRING_LIST_INIT_DUP;
130         int i;
131
132         if (!arg) {
133                 atom->u.remote_ref.option = RR_REF;
134                 refname_atom_parser_internal(&atom->u.remote_ref.refname,
135                                              arg, atom->name);
136                 return;
137         }
138
139         atom->u.remote_ref.nobracket = 0;
140         string_list_split(&params, arg, ',', -1);
141
142         for (i = 0; i < params.nr; i++) {
143                 const char *s = params.items[i].string;
144
145                 if (!strcmp(s, "track"))
146                         atom->u.remote_ref.option = RR_TRACK;
147                 else if (!strcmp(s, "trackshort"))
148                         atom->u.remote_ref.option = RR_TRACKSHORT;
149                 else if (!strcmp(s, "nobracket"))
150                         atom->u.remote_ref.nobracket = 1;
151                 else {
152                         atom->u.remote_ref.option = RR_REF;
153                         refname_atom_parser_internal(&atom->u.remote_ref.refname,
154                                                      arg, atom->name);
155                 }
156         }
157
158         string_list_clear(&params, 0);
159 }
160
161 static void body_atom_parser(struct used_atom *atom, const char *arg)
162 {
163         if (arg)
164                 die(_("%%(body) does not take arguments"));
165         atom->u.contents.option = C_BODY_DEP;
166 }
167
168 static void subject_atom_parser(struct used_atom *atom, const char *arg)
169 {
170         if (arg)
171                 die(_("%%(subject) does not take arguments"));
172         atom->u.contents.option = C_SUB;
173 }
174
175 static void trailers_atom_parser(struct used_atom *atom, const char *arg)
176 {
177         if (arg)
178                 die(_("%%(trailers) does not take arguments"));
179         atom->u.contents.option = C_TRAILERS;
180 }
181
182 static void contents_atom_parser(struct used_atom *atom, const char *arg)
183 {
184         if (!arg)
185                 atom->u.contents.option = C_BARE;
186         else if (!strcmp(arg, "body"))
187                 atom->u.contents.option = C_BODY;
188         else if (!strcmp(arg, "signature"))
189                 atom->u.contents.option = C_SIG;
190         else if (!strcmp(arg, "subject"))
191                 atom->u.contents.option = C_SUB;
192         else if (!strcmp(arg, "trailers"))
193                 atom->u.contents.option = C_TRAILERS;
194         else if (skip_prefix(arg, "lines=", &arg)) {
195                 atom->u.contents.option = C_LINES;
196                 if (strtoul_ui(arg, 10, &atom->u.contents.nlines))
197                         die(_("positive value expected contents:lines=%s"), arg);
198         } else
199                 die(_("unrecognized %%(contents) argument: %s"), arg);
200 }
201
202 static void objectname_atom_parser(struct used_atom *atom, const char *arg)
203 {
204         if (!arg)
205                 atom->u.objectname.option = O_FULL;
206         else if (!strcmp(arg, "short"))
207                 atom->u.objectname.option = O_SHORT;
208         else if (skip_prefix(arg, "short=", &arg)) {
209                 atom->u.objectname.option = O_LENGTH;
210                 if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
211                     atom->u.objectname.length == 0)
212                         die(_("positive value expected objectname:short=%s"), arg);
213                 if (atom->u.objectname.length < MINIMUM_ABBREV)
214                         atom->u.objectname.length = MINIMUM_ABBREV;
215         } else
216                 die(_("unrecognized %%(objectname) argument: %s"), arg);
217 }
218
219 static void refname_atom_parser(struct used_atom *atom, const char *arg)
220 {
221         return refname_atom_parser_internal(&atom->u.refname, arg, atom->name);
222 }
223
224 static align_type parse_align_position(const char *s)
225 {
226         if (!strcmp(s, "right"))
227                 return ALIGN_RIGHT;
228         else if (!strcmp(s, "middle"))
229                 return ALIGN_MIDDLE;
230         else if (!strcmp(s, "left"))
231                 return ALIGN_LEFT;
232         return -1;
233 }
234
235 static void align_atom_parser(struct used_atom *atom, const char *arg)
236 {
237         struct align *align = &atom->u.align;
238         struct string_list params = STRING_LIST_INIT_DUP;
239         int i;
240         unsigned int width = ~0U;
241
242         if (!arg)
243                 die(_("expected format: %%(align:<width>,<position>)"));
244
245         align->position = ALIGN_LEFT;
246
247         string_list_split(&params, arg, ',', -1);
248         for (i = 0; i < params.nr; i++) {
249                 const char *s = params.items[i].string;
250                 int position;
251
252                 if (skip_prefix(s, "position=", &s)) {
253                         position = parse_align_position(s);
254                         if (position < 0)
255                                 die(_("unrecognized position:%s"), s);
256                         align->position = position;
257                 } else if (skip_prefix(s, "width=", &s)) {
258                         if (strtoul_ui(s, 10, &width))
259                                 die(_("unrecognized width:%s"), s);
260                 } else if (!strtoul_ui(s, 10, &width))
261                         ;
262                 else if ((position = parse_align_position(s)) >= 0)
263                         align->position = position;
264                 else
265                         die(_("unrecognized %%(align) argument: %s"), s);
266         }
267
268         if (width == ~0U)
269                 die(_("positive width expected with the %%(align) atom"));
270         align->width = width;
271         string_list_clear(&params, 0);
272 }
273
274 static void if_atom_parser(struct used_atom *atom, const char *arg)
275 {
276         if (!arg) {
277                 atom->u.if_then_else.cmp_status = COMPARE_NONE;
278                 return;
279         } else if (skip_prefix(arg, "equals=", &atom->u.if_then_else.str)) {
280                 atom->u.if_then_else.cmp_status = COMPARE_EQUAL;
281         } else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
282                 atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
283         } else {
284                 die(_("unrecognized %%(if) argument: %s"), arg);
285         }
286 }
287
288
289 static struct {
290         const char *name;
291         cmp_type cmp_type;
292         void (*parser)(struct used_atom *atom, const char *arg);
293 } valid_atom[] = {
294         { "refname" , FIELD_STR, refname_atom_parser },
295         { "objecttype" },
296         { "objectsize", FIELD_ULONG },
297         { "objectname", FIELD_STR, objectname_atom_parser },
298         { "tree" },
299         { "parent" },
300         { "numparent", FIELD_ULONG },
301         { "object" },
302         { "type" },
303         { "tag" },
304         { "author" },
305         { "authorname" },
306         { "authoremail" },
307         { "authordate", FIELD_TIME },
308         { "committer" },
309         { "committername" },
310         { "committeremail" },
311         { "committerdate", FIELD_TIME },
312         { "tagger" },
313         { "taggername" },
314         { "taggeremail" },
315         { "taggerdate", FIELD_TIME },
316         { "creator" },
317         { "creatordate", FIELD_TIME },
318         { "subject", FIELD_STR, subject_atom_parser },
319         { "body", FIELD_STR, body_atom_parser },
320         { "trailers", FIELD_STR, trailers_atom_parser },
321         { "contents", FIELD_STR, contents_atom_parser },
322         { "upstream", FIELD_STR, remote_ref_atom_parser },
323         { "push", FIELD_STR, remote_ref_atom_parser },
324         { "symref", FIELD_STR, refname_atom_parser },
325         { "flag" },
326         { "HEAD" },
327         { "color", FIELD_STR, color_atom_parser },
328         { "align", FIELD_STR, align_atom_parser },
329         { "end" },
330         { "if", FIELD_STR, if_atom_parser },
331         { "then" },
332         { "else" },
333 };
334
335 #define REF_FORMATTING_STATE_INIT  { 0, NULL }
336
337 struct ref_formatting_stack {
338         struct ref_formatting_stack *prev;
339         struct strbuf output;
340         void (*at_end)(struct ref_formatting_stack **stack);
341         void *at_end_data;
342 };
343
344 struct ref_formatting_state {
345         int quote_style;
346         struct ref_formatting_stack *stack;
347 };
348
349 struct atom_value {
350         const char *s;
351         void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
352         unsigned long ul; /* used for sorting when not FIELD_STR */
353         struct used_atom *atom;
354 };
355
356 /*
357  * Used to parse format string and sort specifiers
358  */
359 int parse_ref_filter_atom(const char *atom, const char *ep)
360 {
361         const char *sp;
362         const char *arg;
363         int i, at, atom_len;
364
365         sp = atom;
366         if (*sp == '*' && sp < ep)
367                 sp++; /* deref */
368         if (ep <= sp)
369                 die(_("malformed field name: %.*s"), (int)(ep-atom), atom);
370
371         /* Do we have the atom already used elsewhere? */
372         for (i = 0; i < used_atom_cnt; i++) {
373                 int len = strlen(used_atom[i].name);
374                 if (len == ep - atom && !memcmp(used_atom[i].name, atom, len))
375                         return i;
376         }
377
378         /*
379          * If the atom name has a colon, strip it and everything after
380          * it off - it specifies the format for this entry, and
381          * shouldn't be used for checking against the valid_atom
382          * table.
383          */
384         arg = memchr(sp, ':', ep - sp);
385         atom_len = (arg ? arg : ep) - sp;
386
387         /* Is the atom a valid one? */
388         for (i = 0; i < ARRAY_SIZE(valid_atom); i++) {
389                 int len = strlen(valid_atom[i].name);
390                 if (len == atom_len && !memcmp(valid_atom[i].name, sp, len))
391                         break;
392         }
393
394         if (ARRAY_SIZE(valid_atom) <= i)
395                 die(_("unknown field name: %.*s"), (int)(ep-atom), atom);
396
397         /* Add it in, including the deref prefix */
398         at = used_atom_cnt;
399         used_atom_cnt++;
400         REALLOC_ARRAY(used_atom, used_atom_cnt);
401         used_atom[at].name = xmemdupz(atom, ep - atom);
402         used_atom[at].type = valid_atom[i].cmp_type;
403         if (arg)
404                 arg = used_atom[at].name + (arg - atom) + 1;
405         memset(&used_atom[at].u, 0, sizeof(used_atom[at].u));
406         if (valid_atom[i].parser)
407                 valid_atom[i].parser(&used_atom[at], arg);
408         if (*atom == '*')
409                 need_tagged = 1;
410         if (!strcmp(valid_atom[i].name, "symref"))
411                 need_symref = 1;
412         return at;
413 }
414
415 static void quote_formatting(struct strbuf *s, const char *str, int quote_style)
416 {
417         switch (quote_style) {
418         case QUOTE_NONE:
419                 strbuf_addstr(s, str);
420                 break;
421         case QUOTE_SHELL:
422                 sq_quote_buf(s, str);
423                 break;
424         case QUOTE_PERL:
425                 perl_quote_buf(s, str);
426                 break;
427         case QUOTE_PYTHON:
428                 python_quote_buf(s, str);
429                 break;
430         case QUOTE_TCL:
431                 tcl_quote_buf(s, str);
432                 break;
433         }
434 }
435
436 static void append_atom(struct atom_value *v, struct ref_formatting_state *state)
437 {
438         /*
439          * Quote formatting is only done when the stack has a single
440          * element. Otherwise quote formatting is done on the
441          * element's entire output strbuf when the %(end) atom is
442          * encountered.
443          */
444         if (!state->stack->prev)
445                 quote_formatting(&state->stack->output, v->s, state->quote_style);
446         else
447                 strbuf_addstr(&state->stack->output, v->s);
448 }
449
450 static void push_stack_element(struct ref_formatting_stack **stack)
451 {
452         struct ref_formatting_stack *s = xcalloc(1, sizeof(struct ref_formatting_stack));
453
454         strbuf_init(&s->output, 0);
455         s->prev = *stack;
456         *stack = s;
457 }
458
459 static void pop_stack_element(struct ref_formatting_stack **stack)
460 {
461         struct ref_formatting_stack *current = *stack;
462         struct ref_formatting_stack *prev = current->prev;
463
464         if (prev)
465                 strbuf_addbuf(&prev->output, &current->output);
466         strbuf_release(&current->output);
467         free(current);
468         *stack = prev;
469 }
470
471 static void end_align_handler(struct ref_formatting_stack **stack)
472 {
473         struct ref_formatting_stack *cur = *stack;
474         struct align *align = (struct align *)cur->at_end_data;
475         struct strbuf s = STRBUF_INIT;
476
477         strbuf_utf8_align(&s, align->position, align->width, cur->output.buf);
478         strbuf_swap(&cur->output, &s);
479         strbuf_release(&s);
480 }
481
482 static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
483 {
484         struct ref_formatting_stack *new;
485
486         push_stack_element(&state->stack);
487         new = state->stack;
488         new->at_end = end_align_handler;
489         new->at_end_data = &atomv->atom->u.align;
490 }
491
492 static void if_then_else_handler(struct ref_formatting_stack **stack)
493 {
494         struct ref_formatting_stack *cur = *stack;
495         struct ref_formatting_stack *prev = cur->prev;
496         struct if_then_else *if_then_else = (struct if_then_else *)cur->at_end_data;
497
498         if (!if_then_else->then_atom_seen)
499                 die(_("format: %%(if) atom used without a %%(then) atom"));
500
501         if (if_then_else->else_atom_seen) {
502                 /*
503                  * There is an %(else) atom: we need to drop one state from the
504                  * stack, either the %(else) branch if the condition is satisfied, or
505                  * the %(then) branch if it isn't.
506                  */
507                 if (if_then_else->condition_satisfied) {
508                         strbuf_reset(&cur->output);
509                         pop_stack_element(&cur);
510                 } else {
511                         strbuf_swap(&cur->output, &prev->output);
512                         strbuf_reset(&cur->output);
513                         pop_stack_element(&cur);
514                 }
515         } else if (!if_then_else->condition_satisfied) {
516                 /*
517                  * No %(else) atom: just drop the %(then) branch if the
518                  * condition is not satisfied.
519                  */
520                 strbuf_reset(&cur->output);
521         }
522
523         *stack = cur;
524         free(if_then_else);
525 }
526
527 static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
528 {
529         struct ref_formatting_stack *new;
530         struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
531
532         if_then_else->str = atomv->atom->u.if_then_else.str;
533         if_then_else->cmp_status = atomv->atom->u.if_then_else.cmp_status;
534
535         push_stack_element(&state->stack);
536         new = state->stack;
537         new->at_end = if_then_else_handler;
538         new->at_end_data = if_then_else;
539 }
540
541 static int is_empty(const char *s)
542 {
543         while (*s != '\0') {
544                 if (!isspace(*s))
545                         return 0;
546                 s++;
547         }
548         return 1;
549 }
550
551 static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
552 {
553         struct ref_formatting_stack *cur = state->stack;
554         struct if_then_else *if_then_else = NULL;
555
556         if (cur->at_end == if_then_else_handler)
557                 if_then_else = (struct if_then_else *)cur->at_end_data;
558         if (!if_then_else)
559                 die(_("format: %%(then) atom used without an %%(if) atom"));
560         if (if_then_else->then_atom_seen)
561                 die(_("format: %%(then) atom used more than once"));
562         if (if_then_else->else_atom_seen)
563                 die(_("format: %%(then) atom used after %%(else)"));
564         if_then_else->then_atom_seen = 1;
565         /*
566          * If the 'equals' or 'notequals' attribute is used then
567          * perform the required comparison. If not, only non-empty
568          * strings satisfy the 'if' condition.
569          */
570         if (if_then_else->cmp_status == COMPARE_EQUAL) {
571                 if (!strcmp(if_then_else->str, cur->output.buf))
572                         if_then_else->condition_satisfied = 1;
573         } else if (if_then_else->cmp_status == COMPARE_UNEQUAL) {
574                 if (strcmp(if_then_else->str, cur->output.buf))
575                         if_then_else->condition_satisfied = 1;
576         } else if (cur->output.len && !is_empty(cur->output.buf))
577                 if_then_else->condition_satisfied = 1;
578         strbuf_reset(&cur->output);
579 }
580
581 static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
582 {
583         struct ref_formatting_stack *prev = state->stack;
584         struct if_then_else *if_then_else = NULL;
585
586         if (prev->at_end == if_then_else_handler)
587                 if_then_else = (struct if_then_else *)prev->at_end_data;
588         if (!if_then_else)
589                 die(_("format: %%(else) atom used without an %%(if) atom"));
590         if (!if_then_else->then_atom_seen)
591                 die(_("format: %%(else) atom used without a %%(then) atom"));
592         if (if_then_else->else_atom_seen)
593                 die(_("format: %%(else) atom used more than once"));
594         if_then_else->else_atom_seen = 1;
595         push_stack_element(&state->stack);
596         state->stack->at_end_data = prev->at_end_data;
597         state->stack->at_end = prev->at_end;
598 }
599
600 static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
601 {
602         struct ref_formatting_stack *current = state->stack;
603         struct strbuf s = STRBUF_INIT;
604
605         if (!current->at_end)
606                 die(_("format: %%(end) atom used without corresponding atom"));
607         current->at_end(&state->stack);
608
609         /*  Stack may have been popped within at_end(), hence reset the current pointer */
610         current = state->stack;
611
612         /*
613          * Perform quote formatting when the stack element is that of
614          * a supporting atom. If nested then perform quote formatting
615          * only on the topmost supporting atom.
616          */
617         if (!current->prev->prev) {
618                 quote_formatting(&s, current->output.buf, state->quote_style);
619                 strbuf_swap(&current->output, &s);
620         }
621         strbuf_release(&s);
622         pop_stack_element(&state->stack);
623 }
624
625 /*
626  * In a format string, find the next occurrence of %(atom).
627  */
628 static const char *find_next(const char *cp)
629 {
630         while (*cp) {
631                 if (*cp == '%') {
632                         /*
633                          * %( is the start of an atom;
634                          * %% is a quoted per-cent.
635                          */
636                         if (cp[1] == '(')
637                                 return cp;
638                         else if (cp[1] == '%')
639                                 cp++; /* skip over two % */
640                         /* otherwise this is a singleton, literal % */
641                 }
642                 cp++;
643         }
644         return NULL;
645 }
646
647 /*
648  * Make sure the format string is well formed, and parse out
649  * the used atoms.
650  */
651 int verify_ref_format(const char *format)
652 {
653         const char *cp, *sp;
654
655         need_color_reset_at_eol = 0;
656         for (cp = format; *cp && (sp = find_next(cp)); ) {
657                 const char *color, *ep = strchr(sp, ')');
658                 int at;
659
660                 if (!ep)
661                         return error(_("malformed format string %s"), sp);
662                 /* sp points at "%(" and ep points at the closing ")" */
663                 at = parse_ref_filter_atom(sp + 2, ep);
664                 cp = ep + 1;
665
666                 if (skip_prefix(used_atom[at].name, "color:", &color))
667                         need_color_reset_at_eol = !!strcmp(color, "reset");
668         }
669         return 0;
670 }
671
672 /*
673  * Given an object name, read the object data and size, and return a
674  * "struct object".  If the object data we are returning is also borrowed
675  * by the "struct object" representation, set *eaten as well---it is a
676  * signal from parse_object_buffer to us not to free the buffer.
677  */
678 static void *get_obj(const unsigned char *sha1, struct object **obj, unsigned long *sz, int *eaten)
679 {
680         enum object_type type;
681         void *buf = read_sha1_file(sha1, &type, sz);
682
683         if (buf)
684                 *obj = parse_object_buffer(sha1, type, *sz, buf, eaten);
685         else
686                 *obj = NULL;
687         return buf;
688 }
689
690 static int grab_objectname(const char *name, const unsigned char *sha1,
691                            struct atom_value *v, struct used_atom *atom)
692 {
693         if (starts_with(name, "objectname")) {
694                 if (atom->u.objectname.option == O_SHORT) {
695                         v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
696                         return 1;
697                 } else if (atom->u.objectname.option == O_FULL) {
698                         v->s = xstrdup(sha1_to_hex(sha1));
699                         return 1;
700                 } else if (atom->u.objectname.option == O_LENGTH) {
701                         v->s = xstrdup(find_unique_abbrev(sha1, atom->u.objectname.length));
702                         return 1;
703                 } else
704                         die("BUG: unknown %%(objectname) option");
705         }
706         return 0;
707 }
708
709 /* See grab_values */
710 static void grab_common_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
711 {
712         int i;
713
714         for (i = 0; i < used_atom_cnt; i++) {
715                 const char *name = used_atom[i].name;
716                 struct atom_value *v = &val[i];
717                 if (!!deref != (*name == '*'))
718                         continue;
719                 if (deref)
720                         name++;
721                 if (!strcmp(name, "objecttype"))
722                         v->s = typename(obj->type);
723                 else if (!strcmp(name, "objectsize")) {
724                         v->ul = sz;
725                         v->s = xstrfmt("%lu", sz);
726                 }
727                 else if (deref)
728                         grab_objectname(name, obj->oid.hash, v, &used_atom[i]);
729         }
730 }
731
732 /* See grab_values */
733 static void grab_tag_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
734 {
735         int i;
736         struct tag *tag = (struct tag *) obj;
737
738         for (i = 0; i < used_atom_cnt; i++) {
739                 const char *name = used_atom[i].name;
740                 struct atom_value *v = &val[i];
741                 if (!!deref != (*name == '*'))
742                         continue;
743                 if (deref)
744                         name++;
745                 if (!strcmp(name, "tag"))
746                         v->s = tag->tag;
747                 else if (!strcmp(name, "type") && tag->tagged)
748                         v->s = typename(tag->tagged->type);
749                 else if (!strcmp(name, "object") && tag->tagged)
750                         v->s = xstrdup(oid_to_hex(&tag->tagged->oid));
751         }
752 }
753
754 /* See grab_values */
755 static void grab_commit_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
756 {
757         int i;
758         struct commit *commit = (struct commit *) obj;
759
760         for (i = 0; i < used_atom_cnt; i++) {
761                 const char *name = used_atom[i].name;
762                 struct atom_value *v = &val[i];
763                 if (!!deref != (*name == '*'))
764                         continue;
765                 if (deref)
766                         name++;
767                 if (!strcmp(name, "tree")) {
768                         v->s = xstrdup(oid_to_hex(&commit->tree->object.oid));
769                 }
770                 else if (!strcmp(name, "numparent")) {
771                         v->ul = commit_list_count(commit->parents);
772                         v->s = xstrfmt("%lu", v->ul);
773                 }
774                 else if (!strcmp(name, "parent")) {
775                         struct commit_list *parents;
776                         struct strbuf s = STRBUF_INIT;
777                         for (parents = commit->parents; parents; parents = parents->next) {
778                                 struct commit *parent = parents->item;
779                                 if (parents != commit->parents)
780                                         strbuf_addch(&s, ' ');
781                                 strbuf_addstr(&s, oid_to_hex(&parent->object.oid));
782                         }
783                         v->s = strbuf_detach(&s, NULL);
784                 }
785         }
786 }
787
788 static const char *find_wholine(const char *who, int wholen, const char *buf, unsigned long sz)
789 {
790         const char *eol;
791         while (*buf) {
792                 if (!strncmp(buf, who, wholen) &&
793                     buf[wholen] == ' ')
794                         return buf + wholen + 1;
795                 eol = strchr(buf, '\n');
796                 if (!eol)
797                         return "";
798                 eol++;
799                 if (*eol == '\n')
800                         return ""; /* end of header */
801                 buf = eol;
802         }
803         return "";
804 }
805
806 static const char *copy_line(const char *buf)
807 {
808         const char *eol = strchrnul(buf, '\n');
809         return xmemdupz(buf, eol - buf);
810 }
811
812 static const char *copy_name(const char *buf)
813 {
814         const char *cp;
815         for (cp = buf; *cp && *cp != '\n'; cp++) {
816                 if (!strncmp(cp, " <", 2))
817                         return xmemdupz(buf, cp - buf);
818         }
819         return "";
820 }
821
822 static const char *copy_email(const char *buf)
823 {
824         const char *email = strchr(buf, '<');
825         const char *eoemail;
826         if (!email)
827                 return "";
828         eoemail = strchr(email, '>');
829         if (!eoemail)
830                 return "";
831         return xmemdupz(email, eoemail + 1 - email);
832 }
833
834 static char *copy_subject(const char *buf, unsigned long len)
835 {
836         char *r = xmemdupz(buf, len);
837         int i;
838
839         for (i = 0; i < len; i++)
840                 if (r[i] == '\n')
841                         r[i] = ' ';
842
843         return r;
844 }
845
846 static void grab_date(const char *buf, struct atom_value *v, const char *atomname)
847 {
848         const char *eoemail = strstr(buf, "> ");
849         char *zone;
850         unsigned long timestamp;
851         long tz;
852         struct date_mode date_mode = { DATE_NORMAL };
853         const char *formatp;
854
855         /*
856          * We got here because atomname ends in "date" or "date<something>";
857          * it's not possible that <something> is not ":<format>" because
858          * parse_ref_filter_atom() wouldn't have allowed it, so we can assume that no
859          * ":" means no format is specified, and use the default.
860          */
861         formatp = strchr(atomname, ':');
862         if (formatp != NULL) {
863                 formatp++;
864                 parse_date_format(formatp, &date_mode);
865         }
866
867         if (!eoemail)
868                 goto bad;
869         timestamp = strtoul(eoemail + 2, &zone, 10);
870         if (timestamp == ULONG_MAX)
871                 goto bad;
872         tz = strtol(zone, NULL, 10);
873         if ((tz == LONG_MIN || tz == LONG_MAX) && errno == ERANGE)
874                 goto bad;
875         v->s = xstrdup(show_date(timestamp, tz, &date_mode));
876         v->ul = timestamp;
877         return;
878  bad:
879         v->s = "";
880         v->ul = 0;
881 }
882
883 /* See grab_values */
884 static void grab_person(const char *who, struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
885 {
886         int i;
887         int wholen = strlen(who);
888         const char *wholine = NULL;
889
890         for (i = 0; i < used_atom_cnt; i++) {
891                 const char *name = used_atom[i].name;
892                 struct atom_value *v = &val[i];
893                 if (!!deref != (*name == '*'))
894                         continue;
895                 if (deref)
896                         name++;
897                 if (strncmp(who, name, wholen))
898                         continue;
899                 if (name[wholen] != 0 &&
900                     strcmp(name + wholen, "name") &&
901                     strcmp(name + wholen, "email") &&
902                     !starts_with(name + wholen, "date"))
903                         continue;
904                 if (!wholine)
905                         wholine = find_wholine(who, wholen, buf, sz);
906                 if (!wholine)
907                         return; /* no point looking for it */
908                 if (name[wholen] == 0)
909                         v->s = copy_line(wholine);
910                 else if (!strcmp(name + wholen, "name"))
911                         v->s = copy_name(wholine);
912                 else if (!strcmp(name + wholen, "email"))
913                         v->s = copy_email(wholine);
914                 else if (starts_with(name + wholen, "date"))
915                         grab_date(wholine, v, name);
916         }
917
918         /*
919          * For a tag or a commit object, if "creator" or "creatordate" is
920          * requested, do something special.
921          */
922         if (strcmp(who, "tagger") && strcmp(who, "committer"))
923                 return; /* "author" for commit object is not wanted */
924         if (!wholine)
925                 wholine = find_wholine(who, wholen, buf, sz);
926         if (!wholine)
927                 return;
928         for (i = 0; i < used_atom_cnt; i++) {
929                 const char *name = used_atom[i].name;
930                 struct atom_value *v = &val[i];
931                 if (!!deref != (*name == '*'))
932                         continue;
933                 if (deref)
934                         name++;
935
936                 if (starts_with(name, "creatordate"))
937                         grab_date(wholine, v, name);
938                 else if (!strcmp(name, "creator"))
939                         v->s = copy_line(wholine);
940         }
941 }
942
943 static void find_subpos(const char *buf, unsigned long sz,
944                         const char **sub, unsigned long *sublen,
945                         const char **body, unsigned long *bodylen,
946                         unsigned long *nonsiglen,
947                         const char **sig, unsigned long *siglen)
948 {
949         const char *eol;
950         /* skip past header until we hit empty line */
951         while (*buf && *buf != '\n') {
952                 eol = strchrnul(buf, '\n');
953                 if (*eol)
954                         eol++;
955                 buf = eol;
956         }
957         /* skip any empty lines */
958         while (*buf == '\n')
959                 buf++;
960
961         /* parse signature first; we might not even have a subject line */
962         *sig = buf + parse_signature(buf, strlen(buf));
963         *siglen = strlen(*sig);
964
965         /* subject is first non-empty line */
966         *sub = buf;
967         /* subject goes to first empty line */
968         while (buf < *sig && *buf && *buf != '\n') {
969                 eol = strchrnul(buf, '\n');
970                 if (*eol)
971                         eol++;
972                 buf = eol;
973         }
974         *sublen = buf - *sub;
975         /* drop trailing newline, if present */
976         if (*sublen && (*sub)[*sublen - 1] == '\n')
977                 *sublen -= 1;
978
979         /* skip any empty lines */
980         while (*buf == '\n')
981                 buf++;
982         *body = buf;
983         *bodylen = strlen(buf);
984         *nonsiglen = *sig - buf;
985 }
986
987 /*
988  * If 'lines' is greater than 0, append that many lines from the given
989  * 'buf' of length 'size' to the given strbuf.
990  */
991 static void append_lines(struct strbuf *out, const char *buf, unsigned long size, int lines)
992 {
993         int i;
994         const char *sp, *eol;
995         size_t len;
996
997         sp = buf;
998
999         for (i = 0; i < lines && sp < buf + size; i++) {
1000                 if (i)
1001                         strbuf_addstr(out, "\n    ");
1002                 eol = memchr(sp, '\n', size - (sp - buf));
1003                 len = eol ? eol - sp : size - (sp - buf);
1004                 strbuf_add(out, sp, len);
1005                 if (!eol)
1006                         break;
1007                 sp = eol + 1;
1008         }
1009 }
1010
1011 /* See grab_values */
1012 static void grab_sub_body_contents(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
1013 {
1014         int i;
1015         const char *subpos = NULL, *bodypos = NULL, *sigpos = NULL;
1016         unsigned long sublen = 0, bodylen = 0, nonsiglen = 0, siglen = 0;
1017
1018         for (i = 0; i < used_atom_cnt; i++) {
1019                 struct used_atom *atom = &used_atom[i];
1020                 const char *name = atom->name;
1021                 struct atom_value *v = &val[i];
1022                 if (!!deref != (*name == '*'))
1023                         continue;
1024                 if (deref)
1025                         name++;
1026                 if (strcmp(name, "subject") &&
1027                     strcmp(name, "body") &&
1028                     strcmp(name, "trailers") &&
1029                     !starts_with(name, "contents"))
1030                         continue;
1031                 if (!subpos)
1032                         find_subpos(buf, sz,
1033                                     &subpos, &sublen,
1034                                     &bodypos, &bodylen, &nonsiglen,
1035                                     &sigpos, &siglen);
1036
1037                 if (atom->u.contents.option == C_SUB)
1038                         v->s = copy_subject(subpos, sublen);
1039                 else if (atom->u.contents.option == C_BODY_DEP)
1040                         v->s = xmemdupz(bodypos, bodylen);
1041                 else if (atom->u.contents.option == C_BODY)
1042                         v->s = xmemdupz(bodypos, nonsiglen);
1043                 else if (atom->u.contents.option == C_SIG)
1044                         v->s = xmemdupz(sigpos, siglen);
1045                 else if (atom->u.contents.option == C_LINES) {
1046                         struct strbuf s = STRBUF_INIT;
1047                         const char *contents_end = bodylen + bodypos - siglen;
1048
1049                         /*  Size is the length of the message after removing the signature */
1050                         append_lines(&s, subpos, contents_end - subpos, atom->u.contents.nlines);
1051                         v->s = strbuf_detach(&s, NULL);
1052                 } else if (atom->u.contents.option == C_TRAILERS) {
1053                         struct trailer_info info;
1054
1055                         /* Search for trailer info */
1056                         trailer_info_get(&info, subpos);
1057                         v->s = xmemdupz(info.trailer_start,
1058                                         info.trailer_end - info.trailer_start);
1059                         trailer_info_release(&info);
1060                 } else if (atom->u.contents.option == C_BARE)
1061                         v->s = xstrdup(subpos);
1062         }
1063 }
1064
1065 /*
1066  * We want to have empty print-string for field requests
1067  * that do not apply (e.g. "authordate" for a tag object)
1068  */
1069 static void fill_missing_values(struct atom_value *val)
1070 {
1071         int i;
1072         for (i = 0; i < used_atom_cnt; i++) {
1073                 struct atom_value *v = &val[i];
1074                 if (v->s == NULL)
1075                         v->s = "";
1076         }
1077 }
1078
1079 /*
1080  * val is a list of atom_value to hold returned values.  Extract
1081  * the values for atoms in used_atom array out of (obj, buf, sz).
1082  * when deref is false, (obj, buf, sz) is the object that is
1083  * pointed at by the ref itself; otherwise it is the object the
1084  * ref (which is a tag) refers to.
1085  */
1086 static void grab_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
1087 {
1088         grab_common_values(val, deref, obj, buf, sz);
1089         switch (obj->type) {
1090         case OBJ_TAG:
1091                 grab_tag_values(val, deref, obj, buf, sz);
1092                 grab_sub_body_contents(val, deref, obj, buf, sz);
1093                 grab_person("tagger", val, deref, obj, buf, sz);
1094                 break;
1095         case OBJ_COMMIT:
1096                 grab_commit_values(val, deref, obj, buf, sz);
1097                 grab_sub_body_contents(val, deref, obj, buf, sz);
1098                 grab_person("author", val, deref, obj, buf, sz);
1099                 grab_person("committer", val, deref, obj, buf, sz);
1100                 break;
1101         case OBJ_TREE:
1102                 /* grab_tree_values(val, deref, obj, buf, sz); */
1103                 break;
1104         case OBJ_BLOB:
1105                 /* grab_blob_values(val, deref, obj, buf, sz); */
1106                 break;
1107         default:
1108                 die("Eh?  Object of type %d?", obj->type);
1109         }
1110 }
1111
1112 static inline char *copy_advance(char *dst, const char *src)
1113 {
1114         while (*src)
1115                 *dst++ = *src++;
1116         return dst;
1117 }
1118
1119 static const char *lstrip_ref_components(const char *refname, int len)
1120 {
1121         long remaining = len;
1122         const char *start = refname;
1123
1124         if (len < 0) {
1125                 int i;
1126                 const char *p = refname;
1127
1128                 /* Find total no of '/' separated path-components */
1129                 for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
1130                         ;
1131                 /*
1132                  * The number of components we need to strip is now
1133                  * the total minus the components to be left (Plus one
1134                  * because we count the number of '/', but the number
1135                  * of components is one more than the no of '/').
1136                  */
1137                 remaining = i + len + 1;
1138         }
1139
1140         while (remaining > 0) {
1141                 switch (*start++) {
1142                 case '\0':
1143                         return "";
1144                 case '/':
1145                         remaining--;
1146                         break;
1147                 }
1148         }
1149
1150         return start;
1151 }
1152
1153 static const char *rstrip_ref_components(const char *refname, int len)
1154 {
1155         long remaining = len;
1156         char *start = xstrdup(refname);
1157
1158         if (len < 0) {
1159                 int i;
1160                 const char *p = refname;
1161
1162                 /* Find total no of '/' separated path-components */
1163                 for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
1164                         ;
1165                 /*
1166                  * The number of components we need to strip is now
1167                  * the total minus the components to be left (Plus one
1168                  * because we count the number of '/', but the number
1169                  * of components is one more than the no of '/').
1170                  */
1171                 remaining = i + len + 1;
1172         }
1173
1174         while (remaining-- > 0) {
1175                 char *p = strrchr(start, '/');
1176                 if (p == NULL)
1177                         return "";
1178                 else
1179                         p[0] = '\0';
1180         }
1181         return start;
1182 }
1183
1184 static const char *show_ref(struct refname_atom *atom, const char *refname)
1185 {
1186         if (atom->option == R_SHORT)
1187                 return shorten_unambiguous_ref(refname, warn_ambiguous_refs);
1188         else if (atom->option == R_LSTRIP)
1189                 return lstrip_ref_components(refname, atom->lstrip);
1190         else if (atom->option == R_RSTRIP)
1191                 return rstrip_ref_components(refname, atom->rstrip);
1192         else
1193                 return refname;
1194 }
1195
1196 static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
1197                                     struct branch *branch, const char **s)
1198 {
1199         int num_ours, num_theirs;
1200         if (atom->u.remote_ref.option == RR_REF)
1201                 *s = show_ref(&atom->u.remote_ref.refname, refname);
1202         else if (atom->u.remote_ref.option == RR_TRACK) {
1203                 if (stat_tracking_info(branch, &num_ours,
1204                                        &num_theirs, NULL)) {
1205                         *s = xstrdup(msgs.gone);
1206                 } else if (!num_ours && !num_theirs)
1207                         *s = "";
1208                 else if (!num_ours)
1209                         *s = xstrfmt(msgs.behind, num_theirs);
1210                 else if (!num_theirs)
1211                         *s = xstrfmt(msgs.ahead, num_ours);
1212                 else
1213                         *s = xstrfmt(msgs.ahead_behind,
1214                                      num_ours, num_theirs);
1215                 if (!atom->u.remote_ref.nobracket && *s[0]) {
1216                         const char *to_free = *s;
1217                         *s = xstrfmt("[%s]", *s);
1218                         free((void *)to_free);
1219                 }
1220         } else if (atom->u.remote_ref.option == RR_TRACKSHORT) {
1221                 if (stat_tracking_info(branch, &num_ours,
1222                                        &num_theirs, NULL))
1223                         return;
1224
1225                 if (!num_ours && !num_theirs)
1226                         *s = "=";
1227                 else if (!num_ours)
1228                         *s = "<";
1229                 else if (!num_theirs)
1230                         *s = ">";
1231                 else
1232                         *s = "<>";
1233         } else
1234                 die("BUG: unhandled RR_* enum");
1235 }
1236
1237 char *get_head_description(void)
1238 {
1239         struct strbuf desc = STRBUF_INIT;
1240         struct wt_status_state state;
1241         memset(&state, 0, sizeof(state));
1242         wt_status_get_state(&state, 1);
1243         if (state.rebase_in_progress ||
1244             state.rebase_interactive_in_progress)
1245                 strbuf_addf(&desc, _("(no branch, rebasing %s)"),
1246                             state.branch);
1247         else if (state.bisect_in_progress)
1248                 strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
1249                             state.branch);
1250         else if (state.detached_from) {
1251                 /* TRANSLATORS: make sure these match _("HEAD detached at ")
1252                    and _("HEAD detached from ") in wt-status.c */
1253                 if (state.detached_at)
1254                         strbuf_addf(&desc, _("(HEAD detached at %s)"),
1255                                 state.detached_from);
1256                 else
1257                         strbuf_addf(&desc, _("(HEAD detached from %s)"),
1258                                 state.detached_from);
1259         }
1260         else
1261                 strbuf_addstr(&desc, _("(no branch)"));
1262         free(state.branch);
1263         free(state.onto);
1264         free(state.detached_from);
1265         return strbuf_detach(&desc, NULL);
1266 }
1267
1268 static const char *get_symref(struct used_atom *atom, struct ref_array_item *ref)
1269 {
1270         if (!ref->symref)
1271                 return "";
1272         else
1273                 return show_ref(&atom->u.refname, ref->symref);
1274 }
1275
1276 static const char *get_refname(struct used_atom *atom, struct ref_array_item *ref)
1277 {
1278         if (ref->kind & FILTER_REFS_DETACHED_HEAD)
1279                 return get_head_description();
1280         return show_ref(&atom->u.refname, ref->refname);
1281 }
1282
1283 /*
1284  * Parse the object referred by ref, and grab needed value.
1285  */
1286 static void populate_value(struct ref_array_item *ref)
1287 {
1288         void *buf;
1289         struct object *obj;
1290         int eaten, i;
1291         unsigned long size;
1292         const unsigned char *tagged;
1293
1294         ref->value = xcalloc(used_atom_cnt, sizeof(struct atom_value));
1295
1296         if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
1297                 unsigned char unused1[20];
1298                 ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
1299                                              unused1, NULL);
1300                 if (!ref->symref)
1301                         ref->symref = "";
1302         }
1303
1304         /* Fill in specials first */
1305         for (i = 0; i < used_atom_cnt; i++) {
1306                 struct used_atom *atom = &used_atom[i];
1307                 const char *name = used_atom[i].name;
1308                 struct atom_value *v = &ref->value[i];
1309                 int deref = 0;
1310                 const char *refname;
1311                 struct branch *branch = NULL;
1312
1313                 v->handler = append_atom;
1314                 v->atom = atom;
1315
1316                 if (*name == '*') {
1317                         deref = 1;
1318                         name++;
1319                 }
1320
1321                 if (starts_with(name, "refname"))
1322                         refname = get_refname(atom, ref);
1323                 else if (starts_with(name, "symref"))
1324                         refname = get_symref(atom, ref);
1325                 else if (starts_with(name, "upstream")) {
1326                         const char *branch_name;
1327                         /* only local branches may have an upstream */
1328                         if (!skip_prefix(ref->refname, "refs/heads/",
1329                                          &branch_name))
1330                                 continue;
1331                         branch = branch_get(branch_name);
1332
1333                         refname = branch_get_upstream(branch, NULL);
1334                         if (refname)
1335                                 fill_remote_ref_details(atom, refname, branch, &v->s);
1336                         continue;
1337                 } else if (starts_with(name, "push")) {
1338                         const char *branch_name;
1339                         if (!skip_prefix(ref->refname, "refs/heads/",
1340                                          &branch_name))
1341                                 continue;
1342                         branch = branch_get(branch_name);
1343
1344                         refname = branch_get_push(branch, NULL);
1345                         if (!refname)
1346                                 continue;
1347                         fill_remote_ref_details(atom, refname, branch, &v->s);
1348                         continue;
1349                 } else if (starts_with(name, "color:")) {
1350                         v->s = atom->u.color;
1351                         continue;
1352                 } else if (!strcmp(name, "flag")) {
1353                         char buf[256], *cp = buf;
1354                         if (ref->flag & REF_ISSYMREF)
1355                                 cp = copy_advance(cp, ",symref");
1356                         if (ref->flag & REF_ISPACKED)
1357                                 cp = copy_advance(cp, ",packed");
1358                         if (cp == buf)
1359                                 v->s = "";
1360                         else {
1361                                 *cp = '\0';
1362                                 v->s = xstrdup(buf + 1);
1363                         }
1364                         continue;
1365                 } else if (!deref && grab_objectname(name, ref->objectname, v, atom)) {
1366                         continue;
1367                 } else if (!strcmp(name, "HEAD")) {
1368                         const char *head;
1369                         unsigned char sha1[20];
1370
1371                         head = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
1372                                                   sha1, NULL);
1373                         if (head && !strcmp(ref->refname, head))
1374                                 v->s = "*";
1375                         else
1376                                 v->s = " ";
1377                         continue;
1378                 } else if (starts_with(name, "align")) {
1379                         v->handler = align_atom_handler;
1380                         continue;
1381                 } else if (!strcmp(name, "end")) {
1382                         v->handler = end_atom_handler;
1383                         continue;
1384                 } else if (starts_with(name, "if")) {
1385                         const char *s;
1386
1387                         if (skip_prefix(name, "if:", &s))
1388                                 v->s = xstrdup(s);
1389                         v->handler = if_atom_handler;
1390                         continue;
1391                 } else if (!strcmp(name, "then")) {
1392                         v->handler = then_atom_handler;
1393                         continue;
1394                 } else if (!strcmp(name, "else")) {
1395                         v->handler = else_atom_handler;
1396                         continue;
1397                 } else
1398                         continue;
1399
1400                 if (!deref)
1401                         v->s = refname;
1402                 else
1403                         v->s = xstrfmt("%s^{}", refname);
1404         }
1405
1406         for (i = 0; i < used_atom_cnt; i++) {
1407                 struct atom_value *v = &ref->value[i];
1408                 if (v->s == NULL)
1409                         goto need_obj;
1410         }
1411         return;
1412
1413  need_obj:
1414         buf = get_obj(ref->objectname, &obj, &size, &eaten);
1415         if (!buf)
1416                 die(_("missing object %s for %s"),
1417                     sha1_to_hex(ref->objectname), ref->refname);
1418         if (!obj)
1419                 die(_("parse_object_buffer failed on %s for %s"),
1420                     sha1_to_hex(ref->objectname), ref->refname);
1421
1422         grab_values(ref->value, 0, obj, buf, size);
1423         if (!eaten)
1424                 free(buf);
1425
1426         /*
1427          * If there is no atom that wants to know about tagged
1428          * object, we are done.
1429          */
1430         if (!need_tagged || (obj->type != OBJ_TAG))
1431                 return;
1432
1433         /*
1434          * If it is a tag object, see if we use a value that derefs
1435          * the object, and if we do grab the object it refers to.
1436          */
1437         tagged = ((struct tag *)obj)->tagged->oid.hash;
1438
1439         /*
1440          * NEEDSWORK: This derefs tag only once, which
1441          * is good to deal with chains of trust, but
1442          * is not consistent with what deref_tag() does
1443          * which peels the onion to the core.
1444          */
1445         buf = get_obj(tagged, &obj, &size, &eaten);
1446         if (!buf)
1447                 die(_("missing object %s for %s"),
1448                     sha1_to_hex(tagged), ref->refname);
1449         if (!obj)
1450                 die(_("parse_object_buffer failed on %s for %s"),
1451                     sha1_to_hex(tagged), ref->refname);
1452         grab_values(ref->value, 1, obj, buf, size);
1453         if (!eaten)
1454                 free(buf);
1455 }
1456
1457 /*
1458  * Given a ref, return the value for the atom.  This lazily gets value
1459  * out of the object by calling populate value.
1460  */
1461 static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom_value **v)
1462 {
1463         if (!ref->value) {
1464                 populate_value(ref);
1465                 fill_missing_values(ref->value);
1466         }
1467         *v = &ref->value[atom];
1468 }
1469
1470 enum contains_result {
1471         CONTAINS_UNKNOWN = -1,
1472         CONTAINS_NO = 0,
1473         CONTAINS_YES = 1
1474 };
1475
1476 /*
1477  * Mimicking the real stack, this stack lives on the heap, avoiding stack
1478  * overflows.
1479  *
1480  * At each recursion step, the stack items points to the commits whose
1481  * ancestors are to be inspected.
1482  */
1483 struct contains_stack {
1484         int nr, alloc;
1485         struct contains_stack_entry {
1486                 struct commit *commit;
1487                 struct commit_list *parents;
1488         } *contains_stack;
1489 };
1490
1491 static int in_commit_list(const struct commit_list *want, struct commit *c)
1492 {
1493         for (; want; want = want->next)
1494                 if (!oidcmp(&want->item->object.oid, &c->object.oid))
1495                         return 1;
1496         return 0;
1497 }
1498
1499 /*
1500  * Test whether the candidate or one of its parents is contained in the list.
1501  * Do not recurse to find out, though, but return -1 if inconclusive.
1502  */
1503 static enum contains_result contains_test(struct commit *candidate,
1504                             const struct commit_list *want)
1505 {
1506         /* was it previously marked as containing a want commit? */
1507         if (candidate->object.flags & TMP_MARK)
1508                 return 1;
1509         /* or marked as not possibly containing a want commit? */
1510         if (candidate->object.flags & UNINTERESTING)
1511                 return 0;
1512         /* or are we it? */
1513         if (in_commit_list(want, candidate)) {
1514                 candidate->object.flags |= TMP_MARK;
1515                 return 1;
1516         }
1517
1518         if (parse_commit(candidate) < 0)
1519                 return 0;
1520
1521         return -1;
1522 }
1523
1524 static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
1525 {
1526         ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc);
1527         contains_stack->contains_stack[contains_stack->nr].commit = candidate;
1528         contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents;
1529 }
1530
1531 static enum contains_result contains_tag_algo(struct commit *candidate,
1532                 const struct commit_list *want)
1533 {
1534         struct contains_stack contains_stack = { 0, 0, NULL };
1535         int result = contains_test(candidate, want);
1536
1537         if (result != CONTAINS_UNKNOWN)
1538                 return result;
1539
1540         push_to_contains_stack(candidate, &contains_stack);
1541         while (contains_stack.nr) {
1542                 struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1];
1543                 struct commit *commit = entry->commit;
1544                 struct commit_list *parents = entry->parents;
1545
1546                 if (!parents) {
1547                         commit->object.flags |= UNINTERESTING;
1548                         contains_stack.nr--;
1549                 }
1550                 /*
1551                  * If we just popped the stack, parents->item has been marked,
1552                  * therefore contains_test will return a meaningful 0 or 1.
1553                  */
1554                 else switch (contains_test(parents->item, want)) {
1555                 case CONTAINS_YES:
1556                         commit->object.flags |= TMP_MARK;
1557                         contains_stack.nr--;
1558                         break;
1559                 case CONTAINS_NO:
1560                         entry->parents = parents->next;
1561                         break;
1562                 case CONTAINS_UNKNOWN:
1563                         push_to_contains_stack(parents->item, &contains_stack);
1564                         break;
1565                 }
1566         }
1567         free(contains_stack.contains_stack);
1568         return contains_test(candidate, want);
1569 }
1570
1571 static int commit_contains(struct ref_filter *filter, struct commit *commit)
1572 {
1573         if (filter->with_commit_tag_algo)
1574                 return contains_tag_algo(commit, filter->with_commit);
1575         return is_descendant_of(commit, filter->with_commit);
1576 }
1577
1578 /*
1579  * Return 1 if the refname matches one of the patterns, otherwise 0.
1580  * A pattern can be a literal prefix (e.g. a refname "refs/heads/master"
1581  * matches a pattern "refs/heads/mas") or a wildcard (e.g. the same ref
1582  * matches "refs/heads/mas*", too).
1583  */
1584 static int match_pattern(const struct ref_filter *filter, const char *refname)
1585 {
1586         const char **patterns = filter->name_patterns;
1587         unsigned flags = 0;
1588
1589         if (filter->ignore_case)
1590                 flags |= WM_CASEFOLD;
1591
1592         /*
1593          * When no '--format' option is given we need to skip the prefix
1594          * for matching refs of tags and branches.
1595          */
1596         (void)(skip_prefix(refname, "refs/tags/", &refname) ||
1597                skip_prefix(refname, "refs/heads/", &refname) ||
1598                skip_prefix(refname, "refs/remotes/", &refname) ||
1599                skip_prefix(refname, "refs/", &refname));
1600
1601         for (; *patterns; patterns++) {
1602                 if (!wildmatch(*patterns, refname, flags, NULL))
1603                         return 1;
1604         }
1605         return 0;
1606 }
1607
1608 /*
1609  * Return 1 if the refname matches one of the patterns, otherwise 0.
1610  * A pattern can be path prefix (e.g. a refname "refs/heads/master"
1611  * matches a pattern "refs/heads/" but not "refs/heads/m") or a
1612  * wildcard (e.g. the same ref matches "refs/heads/m*", too).
1613  */
1614 static int match_name_as_path(const struct ref_filter *filter, const char *refname)
1615 {
1616         const char **pattern = filter->name_patterns;
1617         int namelen = strlen(refname);
1618         unsigned flags = WM_PATHNAME;
1619
1620         if (filter->ignore_case)
1621                 flags |= WM_CASEFOLD;
1622
1623         for (; *pattern; pattern++) {
1624                 const char *p = *pattern;
1625                 int plen = strlen(p);
1626
1627                 if ((plen <= namelen) &&
1628                     !strncmp(refname, p, plen) &&
1629                     (refname[plen] == '\0' ||
1630                      refname[plen] == '/' ||
1631                      p[plen-1] == '/'))
1632                         return 1;
1633                 if (!wildmatch(p, refname, WM_PATHNAME, NULL))
1634                         return 1;
1635         }
1636         return 0;
1637 }
1638
1639 /* Return 1 if the refname matches one of the patterns, otherwise 0. */
1640 static int filter_pattern_match(struct ref_filter *filter, const char *refname)
1641 {
1642         if (!*filter->name_patterns)
1643                 return 1; /* No pattern always matches */
1644         if (filter->match_as_path)
1645                 return match_name_as_path(filter, refname);
1646         return match_pattern(filter, refname);
1647 }
1648
1649 /*
1650  * Given a ref (sha1, refname), check if the ref belongs to the array
1651  * of sha1s. If the given ref is a tag, check if the given tag points
1652  * at one of the sha1s in the given sha1 array.
1653  * the given sha1_array.
1654  * NEEDSWORK:
1655  * 1. Only a single level of inderection is obtained, we might want to
1656  * change this to account for multiple levels (e.g. annotated tags
1657  * pointing to annotated tags pointing to a commit.)
1658  * 2. As the refs are cached we might know what refname peels to without
1659  * the need to parse the object via parse_object(). peel_ref() might be a
1660  * more efficient alternative to obtain the pointee.
1661  */
1662 static const unsigned char *match_points_at(struct sha1_array *points_at,
1663                                             const unsigned char *sha1,
1664                                             const char *refname)
1665 {
1666         const unsigned char *tagged_sha1 = NULL;
1667         struct object *obj;
1668
1669         if (sha1_array_lookup(points_at, sha1) >= 0)
1670                 return sha1;
1671         obj = parse_object(sha1);
1672         if (!obj)
1673                 die(_("malformed object at '%s'"), refname);
1674         if (obj->type == OBJ_TAG)
1675                 tagged_sha1 = ((struct tag *)obj)->tagged->oid.hash;
1676         if (tagged_sha1 && sha1_array_lookup(points_at, tagged_sha1) >= 0)
1677                 return tagged_sha1;
1678         return NULL;
1679 }
1680
1681 /* Allocate space for a new ref_array_item and copy the objectname and flag to it */
1682 static struct ref_array_item *new_ref_array_item(const char *refname,
1683                                                  const unsigned char *objectname,
1684                                                  int flag)
1685 {
1686         struct ref_array_item *ref;
1687         FLEX_ALLOC_STR(ref, refname, refname);
1688         hashcpy(ref->objectname, objectname);
1689         ref->flag = flag;
1690
1691         return ref;
1692 }
1693
1694 static int filter_ref_kind(struct ref_filter *filter, const char *refname)
1695 {
1696         unsigned int i;
1697
1698         static struct {
1699                 const char *prefix;
1700                 unsigned int kind;
1701         } ref_kind[] = {
1702                 { "refs/heads/" , FILTER_REFS_BRANCHES },
1703                 { "refs/remotes/" , FILTER_REFS_REMOTES },
1704                 { "refs/tags/", FILTER_REFS_TAGS}
1705         };
1706
1707         if (filter->kind == FILTER_REFS_BRANCHES ||
1708             filter->kind == FILTER_REFS_REMOTES ||
1709             filter->kind == FILTER_REFS_TAGS)
1710                 return filter->kind;
1711         else if (!strcmp(refname, "HEAD"))
1712                 return FILTER_REFS_DETACHED_HEAD;
1713
1714         for (i = 0; i < ARRAY_SIZE(ref_kind); i++) {
1715                 if (starts_with(refname, ref_kind[i].prefix))
1716                         return ref_kind[i].kind;
1717         }
1718
1719         return FILTER_REFS_OTHERS;
1720 }
1721
1722 /*
1723  * A call-back given to for_each_ref().  Filter refs and keep them for
1724  * later object processing.
1725  */
1726 static int ref_filter_handler(const char *refname, const struct object_id *oid, int flag, void *cb_data)
1727 {
1728         struct ref_filter_cbdata *ref_cbdata = cb_data;
1729         struct ref_filter *filter = ref_cbdata->filter;
1730         struct ref_array_item *ref;
1731         struct commit *commit = NULL;
1732         unsigned int kind;
1733
1734         if (flag & REF_BAD_NAME) {
1735                 warning(_("ignoring ref with broken name %s"), refname);
1736                 return 0;
1737         }
1738
1739         if (flag & REF_ISBROKEN) {
1740                 warning(_("ignoring broken ref %s"), refname);
1741                 return 0;
1742         }
1743
1744         /* Obtain the current ref kind from filter_ref_kind() and ignore unwanted refs. */
1745         kind = filter_ref_kind(filter, refname);
1746         if (!(kind & filter->kind))
1747                 return 0;
1748
1749         if (!filter_pattern_match(filter, refname))
1750                 return 0;
1751
1752         if (filter->points_at.nr && !match_points_at(&filter->points_at, oid->hash, refname))
1753                 return 0;
1754
1755         /*
1756          * A merge filter is applied on refs pointing to commits. Hence
1757          * obtain the commit using the 'oid' available and discard all
1758          * non-commits early. The actual filtering is done later.
1759          */
1760         if (filter->merge_commit || filter->with_commit || filter->verbose) {
1761                 commit = lookup_commit_reference_gently(oid->hash, 1);
1762                 if (!commit)
1763                         return 0;
1764                 /* We perform the filtering for the '--contains' option */
1765                 if (filter->with_commit &&
1766                     !commit_contains(filter, commit))
1767                         return 0;
1768         }
1769
1770         /*
1771          * We do not open the object yet; sort may only need refname
1772          * to do its job and the resulting list may yet to be pruned
1773          * by maxcount logic.
1774          */
1775         ref = new_ref_array_item(refname, oid->hash, flag);
1776         ref->commit = commit;
1777
1778         REALLOC_ARRAY(ref_cbdata->array->items, ref_cbdata->array->nr + 1);
1779         ref_cbdata->array->items[ref_cbdata->array->nr++] = ref;
1780         ref->kind = kind;
1781         return 0;
1782 }
1783
1784 /*  Free memory allocated for a ref_array_item */
1785 static void free_array_item(struct ref_array_item *item)
1786 {
1787         free((char *)item->symref);
1788         free(item);
1789 }
1790
1791 /* Free all memory allocated for ref_array */
1792 void ref_array_clear(struct ref_array *array)
1793 {
1794         int i;
1795
1796         for (i = 0; i < array->nr; i++)
1797                 free_array_item(array->items[i]);
1798         free(array->items);
1799         array->items = NULL;
1800         array->nr = array->alloc = 0;
1801 }
1802
1803 static void do_merge_filter(struct ref_filter_cbdata *ref_cbdata)
1804 {
1805         struct rev_info revs;
1806         int i, old_nr;
1807         struct ref_filter *filter = ref_cbdata->filter;
1808         struct ref_array *array = ref_cbdata->array;
1809         struct commit **to_clear = xcalloc(sizeof(struct commit *), array->nr);
1810
1811         init_revisions(&revs, NULL);
1812
1813         for (i = 0; i < array->nr; i++) {
1814                 struct ref_array_item *item = array->items[i];
1815                 add_pending_object(&revs, &item->commit->object, item->refname);
1816                 to_clear[i] = item->commit;
1817         }
1818
1819         filter->merge_commit->object.flags |= UNINTERESTING;
1820         add_pending_object(&revs, &filter->merge_commit->object, "");
1821
1822         revs.limited = 1;
1823         if (prepare_revision_walk(&revs))
1824                 die(_("revision walk setup failed"));
1825
1826         old_nr = array->nr;
1827         array->nr = 0;
1828
1829         for (i = 0; i < old_nr; i++) {
1830                 struct ref_array_item *item = array->items[i];
1831                 struct commit *commit = item->commit;
1832
1833                 int is_merged = !!(commit->object.flags & UNINTERESTING);
1834
1835                 if (is_merged == (filter->merge == REF_FILTER_MERGED_INCLUDE))
1836                         array->items[array->nr++] = array->items[i];
1837                 else
1838                         free_array_item(item);
1839         }
1840
1841         for (i = 0; i < old_nr; i++)
1842                 clear_commit_marks(to_clear[i], ALL_REV_FLAGS);
1843         clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
1844         free(to_clear);
1845 }
1846
1847 /*
1848  * API for filtering a set of refs. Based on the type of refs the user
1849  * has requested, we iterate through those refs and apply filters
1850  * as per the given ref_filter structure and finally store the
1851  * filtered refs in the ref_array structure.
1852  */
1853 int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int type)
1854 {
1855         struct ref_filter_cbdata ref_cbdata;
1856         int ret = 0;
1857         unsigned int broken = 0;
1858
1859         ref_cbdata.array = array;
1860         ref_cbdata.filter = filter;
1861
1862         if (type & FILTER_REFS_INCLUDE_BROKEN)
1863                 broken = 1;
1864         filter->kind = type & FILTER_REFS_KIND_MASK;
1865
1866         /*  Simple per-ref filtering */
1867         if (!filter->kind)
1868                 die("filter_refs: invalid type");
1869         else {
1870                 /*
1871                  * For common cases where we need only branches or remotes or tags,
1872                  * we only iterate through those refs. If a mix of refs is needed,
1873                  * we iterate over all refs and filter out required refs with the help
1874                  * of filter_ref_kind().
1875                  */
1876                 if (filter->kind == FILTER_REFS_BRANCHES)
1877                         ret = for_each_fullref_in("refs/heads/", ref_filter_handler, &ref_cbdata, broken);
1878                 else if (filter->kind == FILTER_REFS_REMOTES)
1879                         ret = for_each_fullref_in("refs/remotes/", ref_filter_handler, &ref_cbdata, broken);
1880                 else if (filter->kind == FILTER_REFS_TAGS)
1881                         ret = for_each_fullref_in("refs/tags/", ref_filter_handler, &ref_cbdata, broken);
1882                 else if (filter->kind & FILTER_REFS_ALL)
1883                         ret = for_each_fullref_in("", ref_filter_handler, &ref_cbdata, broken);
1884                 if (!ret && (filter->kind & FILTER_REFS_DETACHED_HEAD))
1885                         head_ref(ref_filter_handler, &ref_cbdata);
1886         }
1887
1888
1889         /*  Filters that need revision walking */
1890         if (filter->merge_commit)
1891                 do_merge_filter(&ref_cbdata);
1892
1893         return ret;
1894 }
1895
1896 static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, struct ref_array_item *b)
1897 {
1898         struct atom_value *va, *vb;
1899         int cmp;
1900         cmp_type cmp_type = used_atom[s->atom].type;
1901         int (*cmp_fn)(const char *, const char *);
1902
1903         get_ref_atom_value(a, s->atom, &va);
1904         get_ref_atom_value(b, s->atom, &vb);
1905         cmp_fn = s->ignore_case ? strcasecmp : strcmp;
1906         if (s->version)
1907                 cmp = versioncmp(va->s, vb->s);
1908         else if (cmp_type == FIELD_STR)
1909                 cmp = cmp_fn(va->s, vb->s);
1910         else {
1911                 if (va->ul < vb->ul)
1912                         cmp = -1;
1913                 else if (va->ul == vb->ul)
1914                         cmp = cmp_fn(a->refname, b->refname);
1915                 else
1916                         cmp = 1;
1917         }
1918
1919         return (s->reverse) ? -cmp : cmp;
1920 }
1921
1922 static struct ref_sorting *ref_sorting;
1923 static int compare_refs(const void *a_, const void *b_)
1924 {
1925         struct ref_array_item *a = *((struct ref_array_item **)a_);
1926         struct ref_array_item *b = *((struct ref_array_item **)b_);
1927         struct ref_sorting *s;
1928
1929         for (s = ref_sorting; s; s = s->next) {
1930                 int cmp = cmp_ref_sorting(s, a, b);
1931                 if (cmp)
1932                         return cmp;
1933         }
1934         return 0;
1935 }
1936
1937 void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
1938 {
1939         ref_sorting = sorting;
1940         QSORT(array->items, array->nr, compare_refs);
1941 }
1942
1943 static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
1944 {
1945         struct strbuf *s = &state->stack->output;
1946
1947         while (*cp && (!ep || cp < ep)) {
1948                 if (*cp == '%') {
1949                         if (cp[1] == '%')
1950                                 cp++;
1951                         else {
1952                                 int ch = hex2chr(cp + 1);
1953                                 if (0 <= ch) {
1954                                         strbuf_addch(s, ch);
1955                                         cp += 3;
1956                                         continue;
1957                                 }
1958                         }
1959                 }
1960                 strbuf_addch(s, *cp);
1961                 cp++;
1962         }
1963 }
1964
1965 void format_ref_array_item(struct ref_array_item *info, const char *format,
1966                            int quote_style, struct strbuf *final_buf)
1967 {
1968         const char *cp, *sp, *ep;
1969         struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
1970
1971         state.quote_style = quote_style;
1972         push_stack_element(&state.stack);
1973
1974         for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
1975                 struct atom_value *atomv;
1976
1977                 ep = strchr(sp, ')');
1978                 if (cp < sp)
1979                         append_literal(cp, sp, &state);
1980                 get_ref_atom_value(info, parse_ref_filter_atom(sp + 2, ep), &atomv);
1981                 atomv->handler(atomv, &state);
1982         }
1983         if (*cp) {
1984                 sp = cp + strlen(cp);
1985                 append_literal(cp, sp, &state);
1986         }
1987         if (need_color_reset_at_eol) {
1988                 struct atom_value resetv;
1989                 char color[COLOR_MAXLEN] = "";
1990
1991                 if (color_parse("reset", color) < 0)
1992                         die("BUG: couldn't parse 'reset' as a color");
1993                 resetv.s = color;
1994                 append_atom(&resetv, &state);
1995         }
1996         if (state.stack->prev)
1997                 die(_("format: %%(end) atom missing"));
1998         strbuf_addbuf(final_buf, &state.stack->output);
1999         pop_stack_element(&state.stack);
2000 }
2001
2002 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
2003 {
2004         struct strbuf final_buf = STRBUF_INIT;
2005
2006         format_ref_array_item(info, format, quote_style, &final_buf);
2007         fwrite(final_buf.buf, 1, final_buf.len, stdout);
2008         strbuf_release(&final_buf);
2009         putchar('\n');
2010 }
2011
2012 /*  If no sorting option is given, use refname to sort as default */
2013 struct ref_sorting *ref_default_sorting(void)
2014 {
2015         static const char cstr_name[] = "refname";
2016
2017         struct ref_sorting *sorting = xcalloc(1, sizeof(*sorting));
2018
2019         sorting->next = NULL;
2020         sorting->atom = parse_ref_filter_atom(cstr_name, cstr_name + strlen(cstr_name));
2021         return sorting;
2022 }
2023
2024 int parse_opt_ref_sorting(const struct option *opt, const char *arg, int unset)
2025 {
2026         struct ref_sorting **sorting_tail = opt->value;
2027         struct ref_sorting *s;
2028         int len;
2029
2030         if (!arg) /* should --no-sort void the list ? */
2031                 return -1;
2032
2033         s = xcalloc(1, sizeof(*s));
2034         s->next = *sorting_tail;
2035         *sorting_tail = s;
2036
2037         if (*arg == '-') {
2038                 s->reverse = 1;
2039                 arg++;
2040         }
2041         if (skip_prefix(arg, "version:", &arg) ||
2042             skip_prefix(arg, "v:", &arg))
2043                 s->version = 1;
2044         len = strlen(arg);
2045         s->atom = parse_ref_filter_atom(arg, arg+len);
2046         return 0;
2047 }
2048
2049 int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset)
2050 {
2051         struct ref_filter *rf = opt->value;
2052         unsigned char sha1[20];
2053
2054         rf->merge = starts_with(opt->long_name, "no")
2055                 ? REF_FILTER_MERGED_OMIT
2056                 : REF_FILTER_MERGED_INCLUDE;
2057
2058         if (get_sha1(arg, sha1))
2059                 die(_("malformed object name %s"), arg);
2060
2061         rf->merge_commit = lookup_commit_reference_gently(sha1, 0);
2062         if (!rf->merge_commit)
2063                 return opterror(opt, "must point to a commit", 0);
2064
2065         return 0;
2066 }