Merge branch 'vn/line-log-memcpy-size-fix'
[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                  skip_prefix(arg, "strip=", &arg)) {
117                 atom->option = R_LSTRIP;
118                 if (strtol_i(arg, 10, &atom->lstrip))
119                         die(_("Integer value expected refname:lstrip=%s"), arg);
120         } else if (skip_prefix(arg, "rstrip=", &arg)) {
121                 atom->option = R_RSTRIP;
122                 if (strtol_i(arg, 10, &atom->rstrip))
123                         die(_("Integer value expected refname:rstrip=%s"), arg);
124         } else
125                 die(_("unrecognized %%(%s) argument: %s"), name, arg);
126 }
127
128 static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
129 {
130         struct string_list params = STRING_LIST_INIT_DUP;
131         int i;
132
133         if (!arg) {
134                 atom->u.remote_ref.option = RR_REF;
135                 refname_atom_parser_internal(&atom->u.remote_ref.refname,
136                                              arg, atom->name);
137                 return;
138         }
139
140         atom->u.remote_ref.nobracket = 0;
141         string_list_split(&params, arg, ',', -1);
142
143         for (i = 0; i < params.nr; i++) {
144                 const char *s = params.items[i].string;
145
146                 if (!strcmp(s, "track"))
147                         atom->u.remote_ref.option = RR_TRACK;
148                 else if (!strcmp(s, "trackshort"))
149                         atom->u.remote_ref.option = RR_TRACKSHORT;
150                 else if (!strcmp(s, "nobracket"))
151                         atom->u.remote_ref.nobracket = 1;
152                 else {
153                         atom->u.remote_ref.option = RR_REF;
154                         refname_atom_parser_internal(&atom->u.remote_ref.refname,
155                                                      arg, atom->name);
156                 }
157         }
158
159         string_list_clear(&params, 0);
160 }
161
162 static void body_atom_parser(struct used_atom *atom, const char *arg)
163 {
164         if (arg)
165                 die(_("%%(body) does not take arguments"));
166         atom->u.contents.option = C_BODY_DEP;
167 }
168
169 static void subject_atom_parser(struct used_atom *atom, const char *arg)
170 {
171         if (arg)
172                 die(_("%%(subject) does not take arguments"));
173         atom->u.contents.option = C_SUB;
174 }
175
176 static void trailers_atom_parser(struct used_atom *atom, const char *arg)
177 {
178         if (arg)
179                 die(_("%%(trailers) does not take arguments"));
180         atom->u.contents.option = C_TRAILERS;
181 }
182
183 static void contents_atom_parser(struct used_atom *atom, const char *arg)
184 {
185         if (!arg)
186                 atom->u.contents.option = C_BARE;
187         else if (!strcmp(arg, "body"))
188                 atom->u.contents.option = C_BODY;
189         else if (!strcmp(arg, "signature"))
190                 atom->u.contents.option = C_SIG;
191         else if (!strcmp(arg, "subject"))
192                 atom->u.contents.option = C_SUB;
193         else if (!strcmp(arg, "trailers"))
194                 atom->u.contents.option = C_TRAILERS;
195         else if (skip_prefix(arg, "lines=", &arg)) {
196                 atom->u.contents.option = C_LINES;
197                 if (strtoul_ui(arg, 10, &atom->u.contents.nlines))
198                         die(_("positive value expected contents:lines=%s"), arg);
199         } else
200                 die(_("unrecognized %%(contents) argument: %s"), arg);
201 }
202
203 static void objectname_atom_parser(struct used_atom *atom, const char *arg)
204 {
205         if (!arg)
206                 atom->u.objectname.option = O_FULL;
207         else if (!strcmp(arg, "short"))
208                 atom->u.objectname.option = O_SHORT;
209         else if (skip_prefix(arg, "short=", &arg)) {
210                 atom->u.objectname.option = O_LENGTH;
211                 if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
212                     atom->u.objectname.length == 0)
213                         die(_("positive value expected objectname:short=%s"), arg);
214                 if (atom->u.objectname.length < MINIMUM_ABBREV)
215                         atom->u.objectname.length = MINIMUM_ABBREV;
216         } else
217                 die(_("unrecognized %%(objectname) argument: %s"), arg);
218 }
219
220 static void refname_atom_parser(struct used_atom *atom, const char *arg)
221 {
222         return refname_atom_parser_internal(&atom->u.refname, arg, atom->name);
223 }
224
225 static align_type parse_align_position(const char *s)
226 {
227         if (!strcmp(s, "right"))
228                 return ALIGN_RIGHT;
229         else if (!strcmp(s, "middle"))
230                 return ALIGN_MIDDLE;
231         else if (!strcmp(s, "left"))
232                 return ALIGN_LEFT;
233         return -1;
234 }
235
236 static void align_atom_parser(struct used_atom *atom, const char *arg)
237 {
238         struct align *align = &atom->u.align;
239         struct string_list params = STRING_LIST_INIT_DUP;
240         int i;
241         unsigned int width = ~0U;
242
243         if (!arg)
244                 die(_("expected format: %%(align:<width>,<position>)"));
245
246         align->position = ALIGN_LEFT;
247
248         string_list_split(&params, arg, ',', -1);
249         for (i = 0; i < params.nr; i++) {
250                 const char *s = params.items[i].string;
251                 int position;
252
253                 if (skip_prefix(s, "position=", &s)) {
254                         position = parse_align_position(s);
255                         if (position < 0)
256                                 die(_("unrecognized position:%s"), s);
257                         align->position = position;
258                 } else if (skip_prefix(s, "width=", &s)) {
259                         if (strtoul_ui(s, 10, &width))
260                                 die(_("unrecognized width:%s"), s);
261                 } else if (!strtoul_ui(s, 10, &width))
262                         ;
263                 else if ((position = parse_align_position(s)) >= 0)
264                         align->position = position;
265                 else
266                         die(_("unrecognized %%(align) argument: %s"), s);
267         }
268
269         if (width == ~0U)
270                 die(_("positive width expected with the %%(align) atom"));
271         align->width = width;
272         string_list_clear(&params, 0);
273 }
274
275 static void if_atom_parser(struct used_atom *atom, const char *arg)
276 {
277         if (!arg) {
278                 atom->u.if_then_else.cmp_status = COMPARE_NONE;
279                 return;
280         } else if (skip_prefix(arg, "equals=", &atom->u.if_then_else.str)) {
281                 atom->u.if_then_else.cmp_status = COMPARE_EQUAL;
282         } else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
283                 atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
284         } else {
285                 die(_("unrecognized %%(if) argument: %s"), arg);
286         }
287 }
288
289
290 static struct {
291         const char *name;
292         cmp_type cmp_type;
293         void (*parser)(struct used_atom *atom, const char *arg);
294 } valid_atom[] = {
295         { "refname" , FIELD_STR, refname_atom_parser },
296         { "objecttype" },
297         { "objectsize", FIELD_ULONG },
298         { "objectname", FIELD_STR, objectname_atom_parser },
299         { "tree" },
300         { "parent" },
301         { "numparent", FIELD_ULONG },
302         { "object" },
303         { "type" },
304         { "tag" },
305         { "author" },
306         { "authorname" },
307         { "authoremail" },
308         { "authordate", FIELD_TIME },
309         { "committer" },
310         { "committername" },
311         { "committeremail" },
312         { "committerdate", FIELD_TIME },
313         { "tagger" },
314         { "taggername" },
315         { "taggeremail" },
316         { "taggerdate", FIELD_TIME },
317         { "creator" },
318         { "creatordate", FIELD_TIME },
319         { "subject", FIELD_STR, subject_atom_parser },
320         { "body", FIELD_STR, body_atom_parser },
321         { "trailers", FIELD_STR, trailers_atom_parser },
322         { "contents", FIELD_STR, contents_atom_parser },
323         { "upstream", FIELD_STR, remote_ref_atom_parser },
324         { "push", FIELD_STR, remote_ref_atom_parser },
325         { "symref", FIELD_STR, refname_atom_parser },
326         { "flag" },
327         { "HEAD" },
328         { "color", FIELD_STR, color_atom_parser },
329         { "align", FIELD_STR, align_atom_parser },
330         { "end" },
331         { "if", FIELD_STR, if_atom_parser },
332         { "then" },
333         { "else" },
334 };
335
336 #define REF_FORMATTING_STATE_INIT  { 0, NULL }
337
338 struct ref_formatting_stack {
339         struct ref_formatting_stack *prev;
340         struct strbuf output;
341         void (*at_end)(struct ref_formatting_stack **stack);
342         void *at_end_data;
343 };
344
345 struct ref_formatting_state {
346         int quote_style;
347         struct ref_formatting_stack *stack;
348 };
349
350 struct atom_value {
351         const char *s;
352         void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
353         unsigned long ul; /* used for sorting when not FIELD_STR */
354         struct used_atom *atom;
355 };
356
357 /*
358  * Used to parse format string and sort specifiers
359  */
360 int parse_ref_filter_atom(const char *atom, const char *ep)
361 {
362         const char *sp;
363         const char *arg;
364         int i, at, atom_len;
365
366         sp = atom;
367         if (*sp == '*' && sp < ep)
368                 sp++; /* deref */
369         if (ep <= sp)
370                 die(_("malformed field name: %.*s"), (int)(ep-atom), atom);
371
372         /* Do we have the atom already used elsewhere? */
373         for (i = 0; i < used_atom_cnt; i++) {
374                 int len = strlen(used_atom[i].name);
375                 if (len == ep - atom && !memcmp(used_atom[i].name, atom, len))
376                         return i;
377         }
378
379         /*
380          * If the atom name has a colon, strip it and everything after
381          * it off - it specifies the format for this entry, and
382          * shouldn't be used for checking against the valid_atom
383          * table.
384          */
385         arg = memchr(sp, ':', ep - sp);
386         atom_len = (arg ? arg : ep) - sp;
387
388         /* Is the atom a valid one? */
389         for (i = 0; i < ARRAY_SIZE(valid_atom); i++) {
390                 int len = strlen(valid_atom[i].name);
391                 if (len == atom_len && !memcmp(valid_atom[i].name, sp, len))
392                         break;
393         }
394
395         if (ARRAY_SIZE(valid_atom) <= i)
396                 die(_("unknown field name: %.*s"), (int)(ep-atom), atom);
397
398         /* Add it in, including the deref prefix */
399         at = used_atom_cnt;
400         used_atom_cnt++;
401         REALLOC_ARRAY(used_atom, used_atom_cnt);
402         used_atom[at].name = xmemdupz(atom, ep - atom);
403         used_atom[at].type = valid_atom[i].cmp_type;
404         if (arg)
405                 arg = used_atom[at].name + (arg - atom) + 1;
406         memset(&used_atom[at].u, 0, sizeof(used_atom[at].u));
407         if (valid_atom[i].parser)
408                 valid_atom[i].parser(&used_atom[at], arg);
409         if (*atom == '*')
410                 need_tagged = 1;
411         if (!strcmp(valid_atom[i].name, "symref"))
412                 need_symref = 1;
413         return at;
414 }
415
416 static void quote_formatting(struct strbuf *s, const char *str, int quote_style)
417 {
418         switch (quote_style) {
419         case QUOTE_NONE:
420                 strbuf_addstr(s, str);
421                 break;
422         case QUOTE_SHELL:
423                 sq_quote_buf(s, str);
424                 break;
425         case QUOTE_PERL:
426                 perl_quote_buf(s, str);
427                 break;
428         case QUOTE_PYTHON:
429                 python_quote_buf(s, str);
430                 break;
431         case QUOTE_TCL:
432                 tcl_quote_buf(s, str);
433                 break;
434         }
435 }
436
437 static void append_atom(struct atom_value *v, struct ref_formatting_state *state)
438 {
439         /*
440          * Quote formatting is only done when the stack has a single
441          * element. Otherwise quote formatting is done on the
442          * element's entire output strbuf when the %(end) atom is
443          * encountered.
444          */
445         if (!state->stack->prev)
446                 quote_formatting(&state->stack->output, v->s, state->quote_style);
447         else
448                 strbuf_addstr(&state->stack->output, v->s);
449 }
450
451 static void push_stack_element(struct ref_formatting_stack **stack)
452 {
453         struct ref_formatting_stack *s = xcalloc(1, sizeof(struct ref_formatting_stack));
454
455         strbuf_init(&s->output, 0);
456         s->prev = *stack;
457         *stack = s;
458 }
459
460 static void pop_stack_element(struct ref_formatting_stack **stack)
461 {
462         struct ref_formatting_stack *current = *stack;
463         struct ref_formatting_stack *prev = current->prev;
464
465         if (prev)
466                 strbuf_addbuf(&prev->output, &current->output);
467         strbuf_release(&current->output);
468         free(current);
469         *stack = prev;
470 }
471
472 static void end_align_handler(struct ref_formatting_stack **stack)
473 {
474         struct ref_formatting_stack *cur = *stack;
475         struct align *align = (struct align *)cur->at_end_data;
476         struct strbuf s = STRBUF_INIT;
477
478         strbuf_utf8_align(&s, align->position, align->width, cur->output.buf);
479         strbuf_swap(&cur->output, &s);
480         strbuf_release(&s);
481 }
482
483 static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
484 {
485         struct ref_formatting_stack *new;
486
487         push_stack_element(&state->stack);
488         new = state->stack;
489         new->at_end = end_align_handler;
490         new->at_end_data = &atomv->atom->u.align;
491 }
492
493 static void if_then_else_handler(struct ref_formatting_stack **stack)
494 {
495         struct ref_formatting_stack *cur = *stack;
496         struct ref_formatting_stack *prev = cur->prev;
497         struct if_then_else *if_then_else = (struct if_then_else *)cur->at_end_data;
498
499         if (!if_then_else->then_atom_seen)
500                 die(_("format: %%(if) atom used without a %%(then) atom"));
501
502         if (if_then_else->else_atom_seen) {
503                 /*
504                  * There is an %(else) atom: we need to drop one state from the
505                  * stack, either the %(else) branch if the condition is satisfied, or
506                  * the %(then) branch if it isn't.
507                  */
508                 if (if_then_else->condition_satisfied) {
509                         strbuf_reset(&cur->output);
510                         pop_stack_element(&cur);
511                 } else {
512                         strbuf_swap(&cur->output, &prev->output);
513                         strbuf_reset(&cur->output);
514                         pop_stack_element(&cur);
515                 }
516         } else if (!if_then_else->condition_satisfied) {
517                 /*
518                  * No %(else) atom: just drop the %(then) branch if the
519                  * condition is not satisfied.
520                  */
521                 strbuf_reset(&cur->output);
522         }
523
524         *stack = cur;
525         free(if_then_else);
526 }
527
528 static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
529 {
530         struct ref_formatting_stack *new;
531         struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
532
533         if_then_else->str = atomv->atom->u.if_then_else.str;
534         if_then_else->cmp_status = atomv->atom->u.if_then_else.cmp_status;
535
536         push_stack_element(&state->stack);
537         new = state->stack;
538         new->at_end = if_then_else_handler;
539         new->at_end_data = if_then_else;
540 }
541
542 static int is_empty(const char *s)
543 {
544         while (*s != '\0') {
545                 if (!isspace(*s))
546                         return 0;
547                 s++;
548         }
549         return 1;
550 }
551
552 static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
553 {
554         struct ref_formatting_stack *cur = state->stack;
555         struct if_then_else *if_then_else = NULL;
556
557         if (cur->at_end == if_then_else_handler)
558                 if_then_else = (struct if_then_else *)cur->at_end_data;
559         if (!if_then_else)
560                 die(_("format: %%(then) atom used without an %%(if) atom"));
561         if (if_then_else->then_atom_seen)
562                 die(_("format: %%(then) atom used more than once"));
563         if (if_then_else->else_atom_seen)
564                 die(_("format: %%(then) atom used after %%(else)"));
565         if_then_else->then_atom_seen = 1;
566         /*
567          * If the 'equals' or 'notequals' attribute is used then
568          * perform the required comparison. If not, only non-empty
569          * strings satisfy the 'if' condition.
570          */
571         if (if_then_else->cmp_status == COMPARE_EQUAL) {
572                 if (!strcmp(if_then_else->str, cur->output.buf))
573                         if_then_else->condition_satisfied = 1;
574         } else if (if_then_else->cmp_status == COMPARE_UNEQUAL) {
575                 if (strcmp(if_then_else->str, cur->output.buf))
576                         if_then_else->condition_satisfied = 1;
577         } else if (cur->output.len && !is_empty(cur->output.buf))
578                 if_then_else->condition_satisfied = 1;
579         strbuf_reset(&cur->output);
580 }
581
582 static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
583 {
584         struct ref_formatting_stack *prev = state->stack;
585         struct if_then_else *if_then_else = NULL;
586
587         if (prev->at_end == if_then_else_handler)
588                 if_then_else = (struct if_then_else *)prev->at_end_data;
589         if (!if_then_else)
590                 die(_("format: %%(else) atom used without an %%(if) atom"));
591         if (!if_then_else->then_atom_seen)
592                 die(_("format: %%(else) atom used without a %%(then) atom"));
593         if (if_then_else->else_atom_seen)
594                 die(_("format: %%(else) atom used more than once"));
595         if_then_else->else_atom_seen = 1;
596         push_stack_element(&state->stack);
597         state->stack->at_end_data = prev->at_end_data;
598         state->stack->at_end = prev->at_end;
599 }
600
601 static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
602 {
603         struct ref_formatting_stack *current = state->stack;
604         struct strbuf s = STRBUF_INIT;
605
606         if (!current->at_end)
607                 die(_("format: %%(end) atom used without corresponding atom"));
608         current->at_end(&state->stack);
609
610         /*  Stack may have been popped within at_end(), hence reset the current pointer */
611         current = state->stack;
612
613         /*
614          * Perform quote formatting when the stack element is that of
615          * a supporting atom. If nested then perform quote formatting
616          * only on the topmost supporting atom.
617          */
618         if (!current->prev->prev) {
619                 quote_formatting(&s, current->output.buf, state->quote_style);
620                 strbuf_swap(&current->output, &s);
621         }
622         strbuf_release(&s);
623         pop_stack_element(&state->stack);
624 }
625
626 /*
627  * In a format string, find the next occurrence of %(atom).
628  */
629 static const char *find_next(const char *cp)
630 {
631         while (*cp) {
632                 if (*cp == '%') {
633                         /*
634                          * %( is the start of an atom;
635                          * %% is a quoted per-cent.
636                          */
637                         if (cp[1] == '(')
638                                 return cp;
639                         else if (cp[1] == '%')
640                                 cp++; /* skip over two % */
641                         /* otherwise this is a singleton, literal % */
642                 }
643                 cp++;
644         }
645         return NULL;
646 }
647
648 /*
649  * Make sure the format string is well formed, and parse out
650  * the used atoms.
651  */
652 int verify_ref_format(const char *format)
653 {
654         const char *cp, *sp;
655
656         need_color_reset_at_eol = 0;
657         for (cp = format; *cp && (sp = find_next(cp)); ) {
658                 const char *color, *ep = strchr(sp, ')');
659                 int at;
660
661                 if (!ep)
662                         return error(_("malformed format string %s"), sp);
663                 /* sp points at "%(" and ep points at the closing ")" */
664                 at = parse_ref_filter_atom(sp + 2, ep);
665                 cp = ep + 1;
666
667                 if (skip_prefix(used_atom[at].name, "color:", &color))
668                         need_color_reset_at_eol = !!strcmp(color, "reset");
669         }
670         return 0;
671 }
672
673 /*
674  * Given an object name, read the object data and size, and return a
675  * "struct object".  If the object data we are returning is also borrowed
676  * by the "struct object" representation, set *eaten as well---it is a
677  * signal from parse_object_buffer to us not to free the buffer.
678  */
679 static void *get_obj(const unsigned char *sha1, struct object **obj, unsigned long *sz, int *eaten)
680 {
681         enum object_type type;
682         void *buf = read_sha1_file(sha1, &type, sz);
683
684         if (buf)
685                 *obj = parse_object_buffer(sha1, type, *sz, buf, eaten);
686         else
687                 *obj = NULL;
688         return buf;
689 }
690
691 static int grab_objectname(const char *name, const unsigned char *sha1,
692                            struct atom_value *v, struct used_atom *atom)
693 {
694         if (starts_with(name, "objectname")) {
695                 if (atom->u.objectname.option == O_SHORT) {
696                         v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
697                         return 1;
698                 } else if (atom->u.objectname.option == O_FULL) {
699                         v->s = xstrdup(sha1_to_hex(sha1));
700                         return 1;
701                 } else if (atom->u.objectname.option == O_LENGTH) {
702                         v->s = xstrdup(find_unique_abbrev(sha1, atom->u.objectname.length));
703                         return 1;
704                 } else
705                         die("BUG: unknown %%(objectname) option");
706         }
707         return 0;
708 }
709
710 /* See grab_values */
711 static void grab_common_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
712 {
713         int i;
714
715         for (i = 0; i < used_atom_cnt; i++) {
716                 const char *name = used_atom[i].name;
717                 struct atom_value *v = &val[i];
718                 if (!!deref != (*name == '*'))
719                         continue;
720                 if (deref)
721                         name++;
722                 if (!strcmp(name, "objecttype"))
723                         v->s = typename(obj->type);
724                 else if (!strcmp(name, "objectsize")) {
725                         v->ul = sz;
726                         v->s = xstrfmt("%lu", sz);
727                 }
728                 else if (deref)
729                         grab_objectname(name, obj->oid.hash, v, &used_atom[i]);
730         }
731 }
732
733 /* See grab_values */
734 static void grab_tag_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
735 {
736         int i;
737         struct tag *tag = (struct tag *) obj;
738
739         for (i = 0; i < used_atom_cnt; i++) {
740                 const char *name = used_atom[i].name;
741                 struct atom_value *v = &val[i];
742                 if (!!deref != (*name == '*'))
743                         continue;
744                 if (deref)
745                         name++;
746                 if (!strcmp(name, "tag"))
747                         v->s = tag->tag;
748                 else if (!strcmp(name, "type") && tag->tagged)
749                         v->s = typename(tag->tagged->type);
750                 else if (!strcmp(name, "object") && tag->tagged)
751                         v->s = xstrdup(oid_to_hex(&tag->tagged->oid));
752         }
753 }
754
755 /* See grab_values */
756 static void grab_commit_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
757 {
758         int i;
759         struct commit *commit = (struct commit *) obj;
760
761         for (i = 0; i < used_atom_cnt; i++) {
762                 const char *name = used_atom[i].name;
763                 struct atom_value *v = &val[i];
764                 if (!!deref != (*name == '*'))
765                         continue;
766                 if (deref)
767                         name++;
768                 if (!strcmp(name, "tree")) {
769                         v->s = xstrdup(oid_to_hex(&commit->tree->object.oid));
770                 }
771                 else if (!strcmp(name, "numparent")) {
772                         v->ul = commit_list_count(commit->parents);
773                         v->s = xstrfmt("%lu", v->ul);
774                 }
775                 else if (!strcmp(name, "parent")) {
776                         struct commit_list *parents;
777                         struct strbuf s = STRBUF_INIT;
778                         for (parents = commit->parents; parents; parents = parents->next) {
779                                 struct commit *parent = parents->item;
780                                 if (parents != commit->parents)
781                                         strbuf_addch(&s, ' ');
782                                 strbuf_addstr(&s, oid_to_hex(&parent->object.oid));
783                         }
784                         v->s = strbuf_detach(&s, NULL);
785                 }
786         }
787 }
788
789 static const char *find_wholine(const char *who, int wholen, const char *buf, unsigned long sz)
790 {
791         const char *eol;
792         while (*buf) {
793                 if (!strncmp(buf, who, wholen) &&
794                     buf[wholen] == ' ')
795                         return buf + wholen + 1;
796                 eol = strchr(buf, '\n');
797                 if (!eol)
798                         return "";
799                 eol++;
800                 if (*eol == '\n')
801                         return ""; /* end of header */
802                 buf = eol;
803         }
804         return "";
805 }
806
807 static const char *copy_line(const char *buf)
808 {
809         const char *eol = strchrnul(buf, '\n');
810         return xmemdupz(buf, eol - buf);
811 }
812
813 static const char *copy_name(const char *buf)
814 {
815         const char *cp;
816         for (cp = buf; *cp && *cp != '\n'; cp++) {
817                 if (!strncmp(cp, " <", 2))
818                         return xmemdupz(buf, cp - buf);
819         }
820         return "";
821 }
822
823 static const char *copy_email(const char *buf)
824 {
825         const char *email = strchr(buf, '<');
826         const char *eoemail;
827         if (!email)
828                 return "";
829         eoemail = strchr(email, '>');
830         if (!eoemail)
831                 return "";
832         return xmemdupz(email, eoemail + 1 - email);
833 }
834
835 static char *copy_subject(const char *buf, unsigned long len)
836 {
837         char *r = xmemdupz(buf, len);
838         int i;
839
840         for (i = 0; i < len; i++)
841                 if (r[i] == '\n')
842                         r[i] = ' ';
843
844         return r;
845 }
846
847 static void grab_date(const char *buf, struct atom_value *v, const char *atomname)
848 {
849         const char *eoemail = strstr(buf, "> ");
850         char *zone;
851         unsigned long timestamp;
852         long tz;
853         struct date_mode date_mode = { DATE_NORMAL };
854         const char *formatp;
855
856         /*
857          * We got here because atomname ends in "date" or "date<something>";
858          * it's not possible that <something> is not ":<format>" because
859          * parse_ref_filter_atom() wouldn't have allowed it, so we can assume that no
860          * ":" means no format is specified, and use the default.
861          */
862         formatp = strchr(atomname, ':');
863         if (formatp != NULL) {
864                 formatp++;
865                 parse_date_format(formatp, &date_mode);
866         }
867
868         if (!eoemail)
869                 goto bad;
870         timestamp = strtoul(eoemail + 2, &zone, 10);
871         if (timestamp == ULONG_MAX)
872                 goto bad;
873         tz = strtol(zone, NULL, 10);
874         if ((tz == LONG_MIN || tz == LONG_MAX) && errno == ERANGE)
875                 goto bad;
876         v->s = xstrdup(show_date(timestamp, tz, &date_mode));
877         v->ul = timestamp;
878         return;
879  bad:
880         v->s = "";
881         v->ul = 0;
882 }
883
884 /* See grab_values */
885 static void grab_person(const char *who, struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
886 {
887         int i;
888         int wholen = strlen(who);
889         const char *wholine = NULL;
890
891         for (i = 0; i < used_atom_cnt; i++) {
892                 const char *name = used_atom[i].name;
893                 struct atom_value *v = &val[i];
894                 if (!!deref != (*name == '*'))
895                         continue;
896                 if (deref)
897                         name++;
898                 if (strncmp(who, name, wholen))
899                         continue;
900                 if (name[wholen] != 0 &&
901                     strcmp(name + wholen, "name") &&
902                     strcmp(name + wholen, "email") &&
903                     !starts_with(name + wholen, "date"))
904                         continue;
905                 if (!wholine)
906                         wholine = find_wholine(who, wholen, buf, sz);
907                 if (!wholine)
908                         return; /* no point looking for it */
909                 if (name[wholen] == 0)
910                         v->s = copy_line(wholine);
911                 else if (!strcmp(name + wholen, "name"))
912                         v->s = copy_name(wholine);
913                 else if (!strcmp(name + wholen, "email"))
914                         v->s = copy_email(wholine);
915                 else if (starts_with(name + wholen, "date"))
916                         grab_date(wholine, v, name);
917         }
918
919         /*
920          * For a tag or a commit object, if "creator" or "creatordate" is
921          * requested, do something special.
922          */
923         if (strcmp(who, "tagger") && strcmp(who, "committer"))
924                 return; /* "author" for commit object is not wanted */
925         if (!wholine)
926                 wholine = find_wholine(who, wholen, buf, sz);
927         if (!wholine)
928                 return;
929         for (i = 0; i < used_atom_cnt; i++) {
930                 const char *name = used_atom[i].name;
931                 struct atom_value *v = &val[i];
932                 if (!!deref != (*name == '*'))
933                         continue;
934                 if (deref)
935                         name++;
936
937                 if (starts_with(name, "creatordate"))
938                         grab_date(wholine, v, name);
939                 else if (!strcmp(name, "creator"))
940                         v->s = copy_line(wholine);
941         }
942 }
943
944 static void find_subpos(const char *buf, unsigned long sz,
945                         const char **sub, unsigned long *sublen,
946                         const char **body, unsigned long *bodylen,
947                         unsigned long *nonsiglen,
948                         const char **sig, unsigned long *siglen)
949 {
950         const char *eol;
951         /* skip past header until we hit empty line */
952         while (*buf && *buf != '\n') {
953                 eol = strchrnul(buf, '\n');
954                 if (*eol)
955                         eol++;
956                 buf = eol;
957         }
958         /* skip any empty lines */
959         while (*buf == '\n')
960                 buf++;
961
962         /* parse signature first; we might not even have a subject line */
963         *sig = buf + parse_signature(buf, strlen(buf));
964         *siglen = strlen(*sig);
965
966         /* subject is first non-empty line */
967         *sub = buf;
968         /* subject goes to first empty line */
969         while (buf < *sig && *buf && *buf != '\n') {
970                 eol = strchrnul(buf, '\n');
971                 if (*eol)
972                         eol++;
973                 buf = eol;
974         }
975         *sublen = buf - *sub;
976         /* drop trailing newline, if present */
977         if (*sublen && (*sub)[*sublen - 1] == '\n')
978                 *sublen -= 1;
979
980         /* skip any empty lines */
981         while (*buf == '\n')
982                 buf++;
983         *body = buf;
984         *bodylen = strlen(buf);
985         *nonsiglen = *sig - buf;
986 }
987
988 /*
989  * If 'lines' is greater than 0, append that many lines from the given
990  * 'buf' of length 'size' to the given strbuf.
991  */
992 static void append_lines(struct strbuf *out, const char *buf, unsigned long size, int lines)
993 {
994         int i;
995         const char *sp, *eol;
996         size_t len;
997
998         sp = buf;
999
1000         for (i = 0; i < lines && sp < buf + size; i++) {
1001                 if (i)
1002                         strbuf_addstr(out, "\n    ");
1003                 eol = memchr(sp, '\n', size - (sp - buf));
1004                 len = eol ? eol - sp : size - (sp - buf);
1005                 strbuf_add(out, sp, len);
1006                 if (!eol)
1007                         break;
1008                 sp = eol + 1;
1009         }
1010 }
1011
1012 /* See grab_values */
1013 static void grab_sub_body_contents(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
1014 {
1015         int i;
1016         const char *subpos = NULL, *bodypos = NULL, *sigpos = NULL;
1017         unsigned long sublen = 0, bodylen = 0, nonsiglen = 0, siglen = 0;
1018
1019         for (i = 0; i < used_atom_cnt; i++) {
1020                 struct used_atom *atom = &used_atom[i];
1021                 const char *name = atom->name;
1022                 struct atom_value *v = &val[i];
1023                 if (!!deref != (*name == '*'))
1024                         continue;
1025                 if (deref)
1026                         name++;
1027                 if (strcmp(name, "subject") &&
1028                     strcmp(name, "body") &&
1029                     strcmp(name, "trailers") &&
1030                     !starts_with(name, "contents"))
1031                         continue;
1032                 if (!subpos)
1033                         find_subpos(buf, sz,
1034                                     &subpos, &sublen,
1035                                     &bodypos, &bodylen, &nonsiglen,
1036                                     &sigpos, &siglen);
1037
1038                 if (atom->u.contents.option == C_SUB)
1039                         v->s = copy_subject(subpos, sublen);
1040                 else if (atom->u.contents.option == C_BODY_DEP)
1041                         v->s = xmemdupz(bodypos, bodylen);
1042                 else if (atom->u.contents.option == C_BODY)
1043                         v->s = xmemdupz(bodypos, nonsiglen);
1044                 else if (atom->u.contents.option == C_SIG)
1045                         v->s = xmemdupz(sigpos, siglen);
1046                 else if (atom->u.contents.option == C_LINES) {
1047                         struct strbuf s = STRBUF_INIT;
1048                         const char *contents_end = bodylen + bodypos - siglen;
1049
1050                         /*  Size is the length of the message after removing the signature */
1051                         append_lines(&s, subpos, contents_end - subpos, atom->u.contents.nlines);
1052                         v->s = strbuf_detach(&s, NULL);
1053                 } else if (atom->u.contents.option == C_TRAILERS) {
1054                         struct trailer_info info;
1055
1056                         /* Search for trailer info */
1057                         trailer_info_get(&info, subpos);
1058                         v->s = xmemdupz(info.trailer_start,
1059                                         info.trailer_end - info.trailer_start);
1060                         trailer_info_release(&info);
1061                 } else if (atom->u.contents.option == C_BARE)
1062                         v->s = xstrdup(subpos);
1063         }
1064 }
1065
1066 /*
1067  * We want to have empty print-string for field requests
1068  * that do not apply (e.g. "authordate" for a tag object)
1069  */
1070 static void fill_missing_values(struct atom_value *val)
1071 {
1072         int i;
1073         for (i = 0; i < used_atom_cnt; i++) {
1074                 struct atom_value *v = &val[i];
1075                 if (v->s == NULL)
1076                         v->s = "";
1077         }
1078 }
1079
1080 /*
1081  * val is a list of atom_value to hold returned values.  Extract
1082  * the values for atoms in used_atom array out of (obj, buf, sz).
1083  * when deref is false, (obj, buf, sz) is the object that is
1084  * pointed at by the ref itself; otherwise it is the object the
1085  * ref (which is a tag) refers to.
1086  */
1087 static void grab_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
1088 {
1089         grab_common_values(val, deref, obj, buf, sz);
1090         switch (obj->type) {
1091         case OBJ_TAG:
1092                 grab_tag_values(val, deref, obj, buf, sz);
1093                 grab_sub_body_contents(val, deref, obj, buf, sz);
1094                 grab_person("tagger", val, deref, obj, buf, sz);
1095                 break;
1096         case OBJ_COMMIT:
1097                 grab_commit_values(val, deref, obj, buf, sz);
1098                 grab_sub_body_contents(val, deref, obj, buf, sz);
1099                 grab_person("author", val, deref, obj, buf, sz);
1100                 grab_person("committer", val, deref, obj, buf, sz);
1101                 break;
1102         case OBJ_TREE:
1103                 /* grab_tree_values(val, deref, obj, buf, sz); */
1104                 break;
1105         case OBJ_BLOB:
1106                 /* grab_blob_values(val, deref, obj, buf, sz); */
1107                 break;
1108         default:
1109                 die("Eh?  Object of type %d?", obj->type);
1110         }
1111 }
1112
1113 static inline char *copy_advance(char *dst, const char *src)
1114 {
1115         while (*src)
1116                 *dst++ = *src++;
1117         return dst;
1118 }
1119
1120 static const char *lstrip_ref_components(const char *refname, int len)
1121 {
1122         long remaining = len;
1123         const char *start = refname;
1124
1125         if (len < 0) {
1126                 int i;
1127                 const char *p = refname;
1128
1129                 /* Find total no of '/' separated path-components */
1130                 for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
1131                         ;
1132                 /*
1133                  * The number of components we need to strip is now
1134                  * the total minus the components to be left (Plus one
1135                  * because we count the number of '/', but the number
1136                  * of components is one more than the no of '/').
1137                  */
1138                 remaining = i + len + 1;
1139         }
1140
1141         while (remaining > 0) {
1142                 switch (*start++) {
1143                 case '\0':
1144                         return "";
1145                 case '/':
1146                         remaining--;
1147                         break;
1148                 }
1149         }
1150
1151         return start;
1152 }
1153
1154 static const char *rstrip_ref_components(const char *refname, int len)
1155 {
1156         long remaining = len;
1157         char *start = xstrdup(refname);
1158
1159         if (len < 0) {
1160                 int i;
1161                 const char *p = refname;
1162
1163                 /* Find total no of '/' separated path-components */
1164                 for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
1165                         ;
1166                 /*
1167                  * The number of components we need to strip is now
1168                  * the total minus the components to be left (Plus one
1169                  * because we count the number of '/', but the number
1170                  * of components is one more than the no of '/').
1171                  */
1172                 remaining = i + len + 1;
1173         }
1174
1175         while (remaining-- > 0) {
1176                 char *p = strrchr(start, '/');
1177                 if (p == NULL)
1178                         return "";
1179                 else
1180                         p[0] = '\0';
1181         }
1182         return start;
1183 }
1184
1185 static const char *show_ref(struct refname_atom *atom, const char *refname)
1186 {
1187         if (atom->option == R_SHORT)
1188                 return shorten_unambiguous_ref(refname, warn_ambiguous_refs);
1189         else if (atom->option == R_LSTRIP)
1190                 return lstrip_ref_components(refname, atom->lstrip);
1191         else if (atom->option == R_RSTRIP)
1192                 return rstrip_ref_components(refname, atom->rstrip);
1193         else
1194                 return refname;
1195 }
1196
1197 static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
1198                                     struct branch *branch, const char **s)
1199 {
1200         int num_ours, num_theirs;
1201         if (atom->u.remote_ref.option == RR_REF)
1202                 *s = show_ref(&atom->u.remote_ref.refname, refname);
1203         else if (atom->u.remote_ref.option == RR_TRACK) {
1204                 if (stat_tracking_info(branch, &num_ours,
1205                                        &num_theirs, NULL)) {
1206                         *s = xstrdup(msgs.gone);
1207                 } else if (!num_ours && !num_theirs)
1208                         *s = "";
1209                 else if (!num_ours)
1210                         *s = xstrfmt(msgs.behind, num_theirs);
1211                 else if (!num_theirs)
1212                         *s = xstrfmt(msgs.ahead, num_ours);
1213                 else
1214                         *s = xstrfmt(msgs.ahead_behind,
1215                                      num_ours, num_theirs);
1216                 if (!atom->u.remote_ref.nobracket && *s[0]) {
1217                         const char *to_free = *s;
1218                         *s = xstrfmt("[%s]", *s);
1219                         free((void *)to_free);
1220                 }
1221         } else if (atom->u.remote_ref.option == RR_TRACKSHORT) {
1222                 if (stat_tracking_info(branch, &num_ours,
1223                                        &num_theirs, NULL))
1224                         return;
1225
1226                 if (!num_ours && !num_theirs)
1227                         *s = "=";
1228                 else if (!num_ours)
1229                         *s = "<";
1230                 else if (!num_theirs)
1231                         *s = ">";
1232                 else
1233                         *s = "<>";
1234         } else
1235                 die("BUG: unhandled RR_* enum");
1236 }
1237
1238 char *get_head_description(void)
1239 {
1240         struct strbuf desc = STRBUF_INIT;
1241         struct wt_status_state state;
1242         memset(&state, 0, sizeof(state));
1243         wt_status_get_state(&state, 1);
1244         if (state.rebase_in_progress ||
1245             state.rebase_interactive_in_progress)
1246                 strbuf_addf(&desc, _("(no branch, rebasing %s)"),
1247                             state.branch);
1248         else if (state.bisect_in_progress)
1249                 strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
1250                             state.branch);
1251         else if (state.detached_from) {
1252                 if (state.detached_at)
1253                         /* TRANSLATORS: make sure this matches
1254                            "HEAD detached at " in wt-status.c */
1255                         strbuf_addf(&desc, _("(HEAD detached at %s)"),
1256                                 state.detached_from);
1257                 else
1258                         /* TRANSLATORS: make sure this matches
1259                            "HEAD detached from " in wt-status.c */
1260                         strbuf_addf(&desc, _("(HEAD detached from %s)"),
1261                                 state.detached_from);
1262         }
1263         else
1264                 strbuf_addstr(&desc, _("(no branch)"));
1265         free(state.branch);
1266         free(state.onto);
1267         free(state.detached_from);
1268         return strbuf_detach(&desc, NULL);
1269 }
1270
1271 static const char *get_symref(struct used_atom *atom, struct ref_array_item *ref)
1272 {
1273         if (!ref->symref)
1274                 return "";
1275         else
1276                 return show_ref(&atom->u.refname, ref->symref);
1277 }
1278
1279 static const char *get_refname(struct used_atom *atom, struct ref_array_item *ref)
1280 {
1281         if (ref->kind & FILTER_REFS_DETACHED_HEAD)
1282                 return get_head_description();
1283         return show_ref(&atom->u.refname, ref->refname);
1284 }
1285
1286 /*
1287  * Parse the object referred by ref, and grab needed value.
1288  */
1289 static void populate_value(struct ref_array_item *ref)
1290 {
1291         void *buf;
1292         struct object *obj;
1293         int eaten, i;
1294         unsigned long size;
1295         const unsigned char *tagged;
1296
1297         ref->value = xcalloc(used_atom_cnt, sizeof(struct atom_value));
1298
1299         if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
1300                 unsigned char unused1[20];
1301                 ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
1302                                              unused1, NULL);
1303                 if (!ref->symref)
1304                         ref->symref = "";
1305         }
1306
1307         /* Fill in specials first */
1308         for (i = 0; i < used_atom_cnt; i++) {
1309                 struct used_atom *atom = &used_atom[i];
1310                 const char *name = used_atom[i].name;
1311                 struct atom_value *v = &ref->value[i];
1312                 int deref = 0;
1313                 const char *refname;
1314                 struct branch *branch = NULL;
1315
1316                 v->handler = append_atom;
1317                 v->atom = atom;
1318
1319                 if (*name == '*') {
1320                         deref = 1;
1321                         name++;
1322                 }
1323
1324                 if (starts_with(name, "refname"))
1325                         refname = get_refname(atom, ref);
1326                 else if (starts_with(name, "symref"))
1327                         refname = get_symref(atom, ref);
1328                 else if (starts_with(name, "upstream")) {
1329                         const char *branch_name;
1330                         /* only local branches may have an upstream */
1331                         if (!skip_prefix(ref->refname, "refs/heads/",
1332                                          &branch_name))
1333                                 continue;
1334                         branch = branch_get(branch_name);
1335
1336                         refname = branch_get_upstream(branch, NULL);
1337                         if (refname)
1338                                 fill_remote_ref_details(atom, refname, branch, &v->s);
1339                         continue;
1340                 } else if (starts_with(name, "push")) {
1341                         const char *branch_name;
1342                         if (!skip_prefix(ref->refname, "refs/heads/",
1343                                          &branch_name))
1344                                 continue;
1345                         branch = branch_get(branch_name);
1346
1347                         refname = branch_get_push(branch, NULL);
1348                         if (!refname)
1349                                 continue;
1350                         fill_remote_ref_details(atom, refname, branch, &v->s);
1351                         continue;
1352                 } else if (starts_with(name, "color:")) {
1353                         v->s = atom->u.color;
1354                         continue;
1355                 } else if (!strcmp(name, "flag")) {
1356                         char buf[256], *cp = buf;
1357                         if (ref->flag & REF_ISSYMREF)
1358                                 cp = copy_advance(cp, ",symref");
1359                         if (ref->flag & REF_ISPACKED)
1360                                 cp = copy_advance(cp, ",packed");
1361                         if (cp == buf)
1362                                 v->s = "";
1363                         else {
1364                                 *cp = '\0';
1365                                 v->s = xstrdup(buf + 1);
1366                         }
1367                         continue;
1368                 } else if (!deref && grab_objectname(name, ref->objectname, v, atom)) {
1369                         continue;
1370                 } else if (!strcmp(name, "HEAD")) {
1371                         const char *head;
1372                         unsigned char sha1[20];
1373
1374                         head = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
1375                                                   sha1, NULL);
1376                         if (head && !strcmp(ref->refname, head))
1377                                 v->s = "*";
1378                         else
1379                                 v->s = " ";
1380                         continue;
1381                 } else if (starts_with(name, "align")) {
1382                         v->handler = align_atom_handler;
1383                         continue;
1384                 } else if (!strcmp(name, "end")) {
1385                         v->handler = end_atom_handler;
1386                         continue;
1387                 } else if (starts_with(name, "if")) {
1388                         const char *s;
1389
1390                         if (skip_prefix(name, "if:", &s))
1391                                 v->s = xstrdup(s);
1392                         v->handler = if_atom_handler;
1393                         continue;
1394                 } else if (!strcmp(name, "then")) {
1395                         v->handler = then_atom_handler;
1396                         continue;
1397                 } else if (!strcmp(name, "else")) {
1398                         v->handler = else_atom_handler;
1399                         continue;
1400                 } else
1401                         continue;
1402
1403                 if (!deref)
1404                         v->s = refname;
1405                 else
1406                         v->s = xstrfmt("%s^{}", refname);
1407         }
1408
1409         for (i = 0; i < used_atom_cnt; i++) {
1410                 struct atom_value *v = &ref->value[i];
1411                 if (v->s == NULL)
1412                         goto need_obj;
1413         }
1414         return;
1415
1416  need_obj:
1417         buf = get_obj(ref->objectname, &obj, &size, &eaten);
1418         if (!buf)
1419                 die(_("missing object %s for %s"),
1420                     sha1_to_hex(ref->objectname), ref->refname);
1421         if (!obj)
1422                 die(_("parse_object_buffer failed on %s for %s"),
1423                     sha1_to_hex(ref->objectname), ref->refname);
1424
1425         grab_values(ref->value, 0, obj, buf, size);
1426         if (!eaten)
1427                 free(buf);
1428
1429         /*
1430          * If there is no atom that wants to know about tagged
1431          * object, we are done.
1432          */
1433         if (!need_tagged || (obj->type != OBJ_TAG))
1434                 return;
1435
1436         /*
1437          * If it is a tag object, see if we use a value that derefs
1438          * the object, and if we do grab the object it refers to.
1439          */
1440         tagged = ((struct tag *)obj)->tagged->oid.hash;
1441
1442         /*
1443          * NEEDSWORK: This derefs tag only once, which
1444          * is good to deal with chains of trust, but
1445          * is not consistent with what deref_tag() does
1446          * which peels the onion to the core.
1447          */
1448         buf = get_obj(tagged, &obj, &size, &eaten);
1449         if (!buf)
1450                 die(_("missing object %s for %s"),
1451                     sha1_to_hex(tagged), ref->refname);
1452         if (!obj)
1453                 die(_("parse_object_buffer failed on %s for %s"),
1454                     sha1_to_hex(tagged), ref->refname);
1455         grab_values(ref->value, 1, obj, buf, size);
1456         if (!eaten)
1457                 free(buf);
1458 }
1459
1460 /*
1461  * Given a ref, return the value for the atom.  This lazily gets value
1462  * out of the object by calling populate value.
1463  */
1464 static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom_value **v)
1465 {
1466         if (!ref->value) {
1467                 populate_value(ref);
1468                 fill_missing_values(ref->value);
1469         }
1470         *v = &ref->value[atom];
1471 }
1472
1473 enum contains_result {
1474         CONTAINS_UNKNOWN = -1,
1475         CONTAINS_NO = 0,
1476         CONTAINS_YES = 1
1477 };
1478
1479 /*
1480  * Mimicking the real stack, this stack lives on the heap, avoiding stack
1481  * overflows.
1482  *
1483  * At each recursion step, the stack items points to the commits whose
1484  * ancestors are to be inspected.
1485  */
1486 struct contains_stack {
1487         int nr, alloc;
1488         struct contains_stack_entry {
1489                 struct commit *commit;
1490                 struct commit_list *parents;
1491         } *contains_stack;
1492 };
1493
1494 static int in_commit_list(const struct commit_list *want, struct commit *c)
1495 {
1496         for (; want; want = want->next)
1497                 if (!oidcmp(&want->item->object.oid, &c->object.oid))
1498                         return 1;
1499         return 0;
1500 }
1501
1502 /*
1503  * Test whether the candidate or one of its parents is contained in the list.
1504  * Do not recurse to find out, though, but return -1 if inconclusive.
1505  */
1506 static enum contains_result contains_test(struct commit *candidate,
1507                             const struct commit_list *want)
1508 {
1509         /* was it previously marked as containing a want commit? */
1510         if (candidate->object.flags & TMP_MARK)
1511                 return 1;
1512         /* or marked as not possibly containing a want commit? */
1513         if (candidate->object.flags & UNINTERESTING)
1514                 return 0;
1515         /* or are we it? */
1516         if (in_commit_list(want, candidate)) {
1517                 candidate->object.flags |= TMP_MARK;
1518                 return 1;
1519         }
1520
1521         if (parse_commit(candidate) < 0)
1522                 return 0;
1523
1524         return -1;
1525 }
1526
1527 static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
1528 {
1529         ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc);
1530         contains_stack->contains_stack[contains_stack->nr].commit = candidate;
1531         contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents;
1532 }
1533
1534 static enum contains_result contains_tag_algo(struct commit *candidate,
1535                 const struct commit_list *want)
1536 {
1537         struct contains_stack contains_stack = { 0, 0, NULL };
1538         int result = contains_test(candidate, want);
1539
1540         if (result != CONTAINS_UNKNOWN)
1541                 return result;
1542
1543         push_to_contains_stack(candidate, &contains_stack);
1544         while (contains_stack.nr) {
1545                 struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1];
1546                 struct commit *commit = entry->commit;
1547                 struct commit_list *parents = entry->parents;
1548
1549                 if (!parents) {
1550                         commit->object.flags |= UNINTERESTING;
1551                         contains_stack.nr--;
1552                 }
1553                 /*
1554                  * If we just popped the stack, parents->item has been marked,
1555                  * therefore contains_test will return a meaningful 0 or 1.
1556                  */
1557                 else switch (contains_test(parents->item, want)) {
1558                 case CONTAINS_YES:
1559                         commit->object.flags |= TMP_MARK;
1560                         contains_stack.nr--;
1561                         break;
1562                 case CONTAINS_NO:
1563                         entry->parents = parents->next;
1564                         break;
1565                 case CONTAINS_UNKNOWN:
1566                         push_to_contains_stack(parents->item, &contains_stack);
1567                         break;
1568                 }
1569         }
1570         free(contains_stack.contains_stack);
1571         return contains_test(candidate, want);
1572 }
1573
1574 static int commit_contains(struct ref_filter *filter, struct commit *commit)
1575 {
1576         if (filter->with_commit_tag_algo)
1577                 return contains_tag_algo(commit, filter->with_commit);
1578         return is_descendant_of(commit, filter->with_commit);
1579 }
1580
1581 /*
1582  * Return 1 if the refname matches one of the patterns, otherwise 0.
1583  * A pattern can be a literal prefix (e.g. a refname "refs/heads/master"
1584  * matches a pattern "refs/heads/mas") or a wildcard (e.g. the same ref
1585  * matches "refs/heads/mas*", too).
1586  */
1587 static int match_pattern(const struct ref_filter *filter, const char *refname)
1588 {
1589         const char **patterns = filter->name_patterns;
1590         unsigned flags = 0;
1591
1592         if (filter->ignore_case)
1593                 flags |= WM_CASEFOLD;
1594
1595         /*
1596          * When no '--format' option is given we need to skip the prefix
1597          * for matching refs of tags and branches.
1598          */
1599         (void)(skip_prefix(refname, "refs/tags/", &refname) ||
1600                skip_prefix(refname, "refs/heads/", &refname) ||
1601                skip_prefix(refname, "refs/remotes/", &refname) ||
1602                skip_prefix(refname, "refs/", &refname));
1603
1604         for (; *patterns; patterns++) {
1605                 if (!wildmatch(*patterns, refname, flags, NULL))
1606                         return 1;
1607         }
1608         return 0;
1609 }
1610
1611 /*
1612  * Return 1 if the refname matches one of the patterns, otherwise 0.
1613  * A pattern can be path prefix (e.g. a refname "refs/heads/master"
1614  * matches a pattern "refs/heads/" but not "refs/heads/m") or a
1615  * wildcard (e.g. the same ref matches "refs/heads/m*", too).
1616  */
1617 static int match_name_as_path(const struct ref_filter *filter, const char *refname)
1618 {
1619         const char **pattern = filter->name_patterns;
1620         int namelen = strlen(refname);
1621         unsigned flags = WM_PATHNAME;
1622
1623         if (filter->ignore_case)
1624                 flags |= WM_CASEFOLD;
1625
1626         for (; *pattern; pattern++) {
1627                 const char *p = *pattern;
1628                 int plen = strlen(p);
1629
1630                 if ((plen <= namelen) &&
1631                     !strncmp(refname, p, plen) &&
1632                     (refname[plen] == '\0' ||
1633                      refname[plen] == '/' ||
1634                      p[plen-1] == '/'))
1635                         return 1;
1636                 if (!wildmatch(p, refname, WM_PATHNAME, NULL))
1637                         return 1;
1638         }
1639         return 0;
1640 }
1641
1642 /* Return 1 if the refname matches one of the patterns, otherwise 0. */
1643 static int filter_pattern_match(struct ref_filter *filter, const char *refname)
1644 {
1645         if (!*filter->name_patterns)
1646                 return 1; /* No pattern always matches */
1647         if (filter->match_as_path)
1648                 return match_name_as_path(filter, refname);
1649         return match_pattern(filter, refname);
1650 }
1651
1652 /*
1653  * Given a ref (sha1, refname), check if the ref belongs to the array
1654  * of sha1s. If the given ref is a tag, check if the given tag points
1655  * at one of the sha1s in the given sha1 array.
1656  * the given sha1_array.
1657  * NEEDSWORK:
1658  * 1. Only a single level of inderection is obtained, we might want to
1659  * change this to account for multiple levels (e.g. annotated tags
1660  * pointing to annotated tags pointing to a commit.)
1661  * 2. As the refs are cached we might know what refname peels to without
1662  * the need to parse the object via parse_object(). peel_ref() might be a
1663  * more efficient alternative to obtain the pointee.
1664  */
1665 static const unsigned char *match_points_at(struct sha1_array *points_at,
1666                                             const unsigned char *sha1,
1667                                             const char *refname)
1668 {
1669         const unsigned char *tagged_sha1 = NULL;
1670         struct object *obj;
1671
1672         if (sha1_array_lookup(points_at, sha1) >= 0)
1673                 return sha1;
1674         obj = parse_object(sha1);
1675         if (!obj)
1676                 die(_("malformed object at '%s'"), refname);
1677         if (obj->type == OBJ_TAG)
1678                 tagged_sha1 = ((struct tag *)obj)->tagged->oid.hash;
1679         if (tagged_sha1 && sha1_array_lookup(points_at, tagged_sha1) >= 0)
1680                 return tagged_sha1;
1681         return NULL;
1682 }
1683
1684 /* Allocate space for a new ref_array_item and copy the objectname and flag to it */
1685 static struct ref_array_item *new_ref_array_item(const char *refname,
1686                                                  const unsigned char *objectname,
1687                                                  int flag)
1688 {
1689         struct ref_array_item *ref;
1690         FLEX_ALLOC_STR(ref, refname, refname);
1691         hashcpy(ref->objectname, objectname);
1692         ref->flag = flag;
1693
1694         return ref;
1695 }
1696
1697 static int ref_kind_from_refname(const char *refname)
1698 {
1699         unsigned int i;
1700
1701         static struct {
1702                 const char *prefix;
1703                 unsigned int kind;
1704         } ref_kind[] = {
1705                 { "refs/heads/" , FILTER_REFS_BRANCHES },
1706                 { "refs/remotes/" , FILTER_REFS_REMOTES },
1707                 { "refs/tags/", FILTER_REFS_TAGS}
1708         };
1709
1710         if (!strcmp(refname, "HEAD"))
1711                 return FILTER_REFS_DETACHED_HEAD;
1712
1713         for (i = 0; i < ARRAY_SIZE(ref_kind); i++) {
1714                 if (starts_with(refname, ref_kind[i].prefix))
1715                         return ref_kind[i].kind;
1716         }
1717
1718         return FILTER_REFS_OTHERS;
1719 }
1720
1721 static int filter_ref_kind(struct ref_filter *filter, const char *refname)
1722 {
1723         if (filter->kind == FILTER_REFS_BRANCHES ||
1724             filter->kind == FILTER_REFS_REMOTES ||
1725             filter->kind == FILTER_REFS_TAGS)
1726                 return filter->kind;
1727         return ref_kind_from_refname(refname);
1728 }
1729
1730 /*
1731  * A call-back given to for_each_ref().  Filter refs and keep them for
1732  * later object processing.
1733  */
1734 static int ref_filter_handler(const char *refname, const struct object_id *oid, int flag, void *cb_data)
1735 {
1736         struct ref_filter_cbdata *ref_cbdata = cb_data;
1737         struct ref_filter *filter = ref_cbdata->filter;
1738         struct ref_array_item *ref;
1739         struct commit *commit = NULL;
1740         unsigned int kind;
1741
1742         if (flag & REF_BAD_NAME) {
1743                 warning(_("ignoring ref with broken name %s"), refname);
1744                 return 0;
1745         }
1746
1747         if (flag & REF_ISBROKEN) {
1748                 warning(_("ignoring broken ref %s"), refname);
1749                 return 0;
1750         }
1751
1752         /* Obtain the current ref kind from filter_ref_kind() and ignore unwanted refs. */
1753         kind = filter_ref_kind(filter, refname);
1754         if (!(kind & filter->kind))
1755                 return 0;
1756
1757         if (!filter_pattern_match(filter, refname))
1758                 return 0;
1759
1760         if (filter->points_at.nr && !match_points_at(&filter->points_at, oid->hash, refname))
1761                 return 0;
1762
1763         /*
1764          * A merge filter is applied on refs pointing to commits. Hence
1765          * obtain the commit using the 'oid' available and discard all
1766          * non-commits early. The actual filtering is done later.
1767          */
1768         if (filter->merge_commit || filter->with_commit || filter->verbose) {
1769                 commit = lookup_commit_reference_gently(oid->hash, 1);
1770                 if (!commit)
1771                         return 0;
1772                 /* We perform the filtering for the '--contains' option */
1773                 if (filter->with_commit &&
1774                     !commit_contains(filter, commit))
1775                         return 0;
1776         }
1777
1778         /*
1779          * We do not open the object yet; sort may only need refname
1780          * to do its job and the resulting list may yet to be pruned
1781          * by maxcount logic.
1782          */
1783         ref = new_ref_array_item(refname, oid->hash, flag);
1784         ref->commit = commit;
1785
1786         REALLOC_ARRAY(ref_cbdata->array->items, ref_cbdata->array->nr + 1);
1787         ref_cbdata->array->items[ref_cbdata->array->nr++] = ref;
1788         ref->kind = kind;
1789         return 0;
1790 }
1791
1792 /*  Free memory allocated for a ref_array_item */
1793 static void free_array_item(struct ref_array_item *item)
1794 {
1795         free((char *)item->symref);
1796         free(item);
1797 }
1798
1799 /* Free all memory allocated for ref_array */
1800 void ref_array_clear(struct ref_array *array)
1801 {
1802         int i;
1803
1804         for (i = 0; i < array->nr; i++)
1805                 free_array_item(array->items[i]);
1806         free(array->items);
1807         array->items = NULL;
1808         array->nr = array->alloc = 0;
1809 }
1810
1811 static void do_merge_filter(struct ref_filter_cbdata *ref_cbdata)
1812 {
1813         struct rev_info revs;
1814         int i, old_nr;
1815         struct ref_filter *filter = ref_cbdata->filter;
1816         struct ref_array *array = ref_cbdata->array;
1817         struct commit **to_clear = xcalloc(sizeof(struct commit *), array->nr);
1818
1819         init_revisions(&revs, NULL);
1820
1821         for (i = 0; i < array->nr; i++) {
1822                 struct ref_array_item *item = array->items[i];
1823                 add_pending_object(&revs, &item->commit->object, item->refname);
1824                 to_clear[i] = item->commit;
1825         }
1826
1827         filter->merge_commit->object.flags |= UNINTERESTING;
1828         add_pending_object(&revs, &filter->merge_commit->object, "");
1829
1830         revs.limited = 1;
1831         if (prepare_revision_walk(&revs))
1832                 die(_("revision walk setup failed"));
1833
1834         old_nr = array->nr;
1835         array->nr = 0;
1836
1837         for (i = 0; i < old_nr; i++) {
1838                 struct ref_array_item *item = array->items[i];
1839                 struct commit *commit = item->commit;
1840
1841                 int is_merged = !!(commit->object.flags & UNINTERESTING);
1842
1843                 if (is_merged == (filter->merge == REF_FILTER_MERGED_INCLUDE))
1844                         array->items[array->nr++] = array->items[i];
1845                 else
1846                         free_array_item(item);
1847         }
1848
1849         for (i = 0; i < old_nr; i++)
1850                 clear_commit_marks(to_clear[i], ALL_REV_FLAGS);
1851         clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
1852         free(to_clear);
1853 }
1854
1855 /*
1856  * API for filtering a set of refs. Based on the type of refs the user
1857  * has requested, we iterate through those refs and apply filters
1858  * as per the given ref_filter structure and finally store the
1859  * filtered refs in the ref_array structure.
1860  */
1861 int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int type)
1862 {
1863         struct ref_filter_cbdata ref_cbdata;
1864         int ret = 0;
1865         unsigned int broken = 0;
1866
1867         ref_cbdata.array = array;
1868         ref_cbdata.filter = filter;
1869
1870         if (type & FILTER_REFS_INCLUDE_BROKEN)
1871                 broken = 1;
1872         filter->kind = type & FILTER_REFS_KIND_MASK;
1873
1874         /*  Simple per-ref filtering */
1875         if (!filter->kind)
1876                 die("filter_refs: invalid type");
1877         else {
1878                 /*
1879                  * For common cases where we need only branches or remotes or tags,
1880                  * we only iterate through those refs. If a mix of refs is needed,
1881                  * we iterate over all refs and filter out required refs with the help
1882                  * of filter_ref_kind().
1883                  */
1884                 if (filter->kind == FILTER_REFS_BRANCHES)
1885                         ret = for_each_fullref_in("refs/heads/", ref_filter_handler, &ref_cbdata, broken);
1886                 else if (filter->kind == FILTER_REFS_REMOTES)
1887                         ret = for_each_fullref_in("refs/remotes/", ref_filter_handler, &ref_cbdata, broken);
1888                 else if (filter->kind == FILTER_REFS_TAGS)
1889                         ret = for_each_fullref_in("refs/tags/", ref_filter_handler, &ref_cbdata, broken);
1890                 else if (filter->kind & FILTER_REFS_ALL)
1891                         ret = for_each_fullref_in("", ref_filter_handler, &ref_cbdata, broken);
1892                 if (!ret && (filter->kind & FILTER_REFS_DETACHED_HEAD))
1893                         head_ref(ref_filter_handler, &ref_cbdata);
1894         }
1895
1896
1897         /*  Filters that need revision walking */
1898         if (filter->merge_commit)
1899                 do_merge_filter(&ref_cbdata);
1900
1901         return ret;
1902 }
1903
1904 static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, struct ref_array_item *b)
1905 {
1906         struct atom_value *va, *vb;
1907         int cmp;
1908         cmp_type cmp_type = used_atom[s->atom].type;
1909         int (*cmp_fn)(const char *, const char *);
1910
1911         get_ref_atom_value(a, s->atom, &va);
1912         get_ref_atom_value(b, s->atom, &vb);
1913         cmp_fn = s->ignore_case ? strcasecmp : strcmp;
1914         if (s->version)
1915                 cmp = versioncmp(va->s, vb->s);
1916         else if (cmp_type == FIELD_STR)
1917                 cmp = cmp_fn(va->s, vb->s);
1918         else {
1919                 if (va->ul < vb->ul)
1920                         cmp = -1;
1921                 else if (va->ul == vb->ul)
1922                         cmp = cmp_fn(a->refname, b->refname);
1923                 else
1924                         cmp = 1;
1925         }
1926
1927         return (s->reverse) ? -cmp : cmp;
1928 }
1929
1930 static int compare_refs(const void *a_, const void *b_, void *ref_sorting)
1931 {
1932         struct ref_array_item *a = *((struct ref_array_item **)a_);
1933         struct ref_array_item *b = *((struct ref_array_item **)b_);
1934         struct ref_sorting *s;
1935
1936         for (s = ref_sorting; s; s = s->next) {
1937                 int cmp = cmp_ref_sorting(s, a, b);
1938                 if (cmp)
1939                         return cmp;
1940         }
1941         return 0;
1942 }
1943
1944 void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
1945 {
1946         QSORT_S(array->items, array->nr, compare_refs, sorting);
1947 }
1948
1949 static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
1950 {
1951         struct strbuf *s = &state->stack->output;
1952
1953         while (*cp && (!ep || cp < ep)) {
1954                 if (*cp == '%') {
1955                         if (cp[1] == '%')
1956                                 cp++;
1957                         else {
1958                                 int ch = hex2chr(cp + 1);
1959                                 if (0 <= ch) {
1960                                         strbuf_addch(s, ch);
1961                                         cp += 3;
1962                                         continue;
1963                                 }
1964                         }
1965                 }
1966                 strbuf_addch(s, *cp);
1967                 cp++;
1968         }
1969 }
1970
1971 void format_ref_array_item(struct ref_array_item *info, const char *format,
1972                            int quote_style, struct strbuf *final_buf)
1973 {
1974         const char *cp, *sp, *ep;
1975         struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
1976
1977         state.quote_style = quote_style;
1978         push_stack_element(&state.stack);
1979
1980         for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
1981                 struct atom_value *atomv;
1982
1983                 ep = strchr(sp, ')');
1984                 if (cp < sp)
1985                         append_literal(cp, sp, &state);
1986                 get_ref_atom_value(info, parse_ref_filter_atom(sp + 2, ep), &atomv);
1987                 atomv->handler(atomv, &state);
1988         }
1989         if (*cp) {
1990                 sp = cp + strlen(cp);
1991                 append_literal(cp, sp, &state);
1992         }
1993         if (need_color_reset_at_eol) {
1994                 struct atom_value resetv;
1995                 char color[COLOR_MAXLEN] = "";
1996
1997                 if (color_parse("reset", color) < 0)
1998                         die("BUG: couldn't parse 'reset' as a color");
1999                 resetv.s = color;
2000                 append_atom(&resetv, &state);
2001         }
2002         if (state.stack->prev)
2003                 die(_("format: %%(end) atom missing"));
2004         strbuf_addbuf(final_buf, &state.stack->output);
2005         pop_stack_element(&state.stack);
2006 }
2007
2008 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
2009 {
2010         struct strbuf final_buf = STRBUF_INIT;
2011
2012         format_ref_array_item(info, format, quote_style, &final_buf);
2013         fwrite(final_buf.buf, 1, final_buf.len, stdout);
2014         strbuf_release(&final_buf);
2015         putchar('\n');
2016 }
2017
2018 void pretty_print_ref(const char *name, const unsigned char *sha1,
2019                 const char *format)
2020 {
2021         struct ref_array_item *ref_item;
2022         ref_item = new_ref_array_item(name, sha1, 0);
2023         ref_item->kind = ref_kind_from_refname(name);
2024         show_ref_array_item(ref_item, format, 0);
2025         free_array_item(ref_item);
2026 }
2027
2028 /*  If no sorting option is given, use refname to sort as default */
2029 struct ref_sorting *ref_default_sorting(void)
2030 {
2031         static const char cstr_name[] = "refname";
2032
2033         struct ref_sorting *sorting = xcalloc(1, sizeof(*sorting));
2034
2035         sorting->next = NULL;
2036         sorting->atom = parse_ref_filter_atom(cstr_name, cstr_name + strlen(cstr_name));
2037         return sorting;
2038 }
2039
2040 int parse_opt_ref_sorting(const struct option *opt, const char *arg, int unset)
2041 {
2042         struct ref_sorting **sorting_tail = opt->value;
2043         struct ref_sorting *s;
2044         int len;
2045
2046         if (!arg) /* should --no-sort void the list ? */
2047                 return -1;
2048
2049         s = xcalloc(1, sizeof(*s));
2050         s->next = *sorting_tail;
2051         *sorting_tail = s;
2052
2053         if (*arg == '-') {
2054                 s->reverse = 1;
2055                 arg++;
2056         }
2057         if (skip_prefix(arg, "version:", &arg) ||
2058             skip_prefix(arg, "v:", &arg))
2059                 s->version = 1;
2060         len = strlen(arg);
2061         s->atom = parse_ref_filter_atom(arg, arg+len);
2062         return 0;
2063 }
2064
2065 int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset)
2066 {
2067         struct ref_filter *rf = opt->value;
2068         unsigned char sha1[20];
2069
2070         rf->merge = starts_with(opt->long_name, "no")
2071                 ? REF_FILTER_MERGED_OMIT
2072                 : REF_FILTER_MERGED_INCLUDE;
2073
2074         if (get_sha1(arg, sha1))
2075                 die(_("malformed object name %s"), arg);
2076
2077         rf->merge_commit = lookup_commit_reference_gently(sha1, 0);
2078         if (!rf->merge_commit)
2079                 return opterror(opt, "must point to a commit", 0);
2080
2081         return 0;
2082 }