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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                 char *head;
96         } u;
97 } *used_atom;
98 static int used_atom_cnt, need_tagged, need_symref;
99 static int need_color_reset_at_eol;
100
101 static void color_atom_parser(struct used_atom *atom, const char *color_value)
102 {
103         if (!color_value)
104                 die(_("expected format: %%(color:<color>)"));
105         if (color_parse(color_value, atom->u.color) < 0)
106                 die(_("unrecognized color: %%(color:%s)"), color_value);
107 }
108
109 static void refname_atom_parser_internal(struct refname_atom *atom,
110                                          const char *arg, const char *name)
111 {
112         if (!arg)
113                 atom->option = R_NORMAL;
114         else if (!strcmp(arg, "short"))
115                 atom->option = R_SHORT;
116         else if (skip_prefix(arg, "lstrip=", &arg) ||
117                  skip_prefix(arg, "strip=", &arg)) {
118                 atom->option = R_LSTRIP;
119                 if (strtol_i(arg, 10, &atom->lstrip))
120                         die(_("Integer value expected refname:lstrip=%s"), arg);
121         } else if (skip_prefix(arg, "rstrip=", &arg)) {
122                 atom->option = R_RSTRIP;
123                 if (strtol_i(arg, 10, &atom->rstrip))
124                         die(_("Integer value expected refname:rstrip=%s"), arg);
125         } else
126                 die(_("unrecognized %%(%s) argument: %s"), name, arg);
127 }
128
129 static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
130 {
131         struct string_list params = STRING_LIST_INIT_DUP;
132         int i;
133
134         if (!arg) {
135                 atom->u.remote_ref.option = RR_REF;
136                 refname_atom_parser_internal(&atom->u.remote_ref.refname,
137                                              arg, atom->name);
138                 return;
139         }
140
141         atom->u.remote_ref.nobracket = 0;
142         string_list_split(&params, arg, ',', -1);
143
144         for (i = 0; i < params.nr; i++) {
145                 const char *s = params.items[i].string;
146
147                 if (!strcmp(s, "track"))
148                         atom->u.remote_ref.option = RR_TRACK;
149                 else if (!strcmp(s, "trackshort"))
150                         atom->u.remote_ref.option = RR_TRACKSHORT;
151                 else if (!strcmp(s, "nobracket"))
152                         atom->u.remote_ref.nobracket = 1;
153                 else {
154                         atom->u.remote_ref.option = RR_REF;
155                         refname_atom_parser_internal(&atom->u.remote_ref.refname,
156                                                      arg, atom->name);
157                 }
158         }
159
160         string_list_clear(&params, 0);
161 }
162
163 static void body_atom_parser(struct used_atom *atom, const char *arg)
164 {
165         if (arg)
166                 die(_("%%(body) does not take arguments"));
167         atom->u.contents.option = C_BODY_DEP;
168 }
169
170 static void subject_atom_parser(struct used_atom *atom, const char *arg)
171 {
172         if (arg)
173                 die(_("%%(subject) does not take arguments"));
174         atom->u.contents.option = C_SUB;
175 }
176
177 static void trailers_atom_parser(struct used_atom *atom, const char *arg)
178 {
179         if (arg)
180                 die(_("%%(trailers) does not take arguments"));
181         atom->u.contents.option = C_TRAILERS;
182 }
183
184 static void contents_atom_parser(struct used_atom *atom, const char *arg)
185 {
186         if (!arg)
187                 atom->u.contents.option = C_BARE;
188         else if (!strcmp(arg, "body"))
189                 atom->u.contents.option = C_BODY;
190         else if (!strcmp(arg, "signature"))
191                 atom->u.contents.option = C_SIG;
192         else if (!strcmp(arg, "subject"))
193                 atom->u.contents.option = C_SUB;
194         else if (!strcmp(arg, "trailers"))
195                 atom->u.contents.option = C_TRAILERS;
196         else if (skip_prefix(arg, "lines=", &arg)) {
197                 atom->u.contents.option = C_LINES;
198                 if (strtoul_ui(arg, 10, &atom->u.contents.nlines))
199                         die(_("positive value expected contents:lines=%s"), arg);
200         } else
201                 die(_("unrecognized %%(contents) argument: %s"), arg);
202 }
203
204 static void objectname_atom_parser(struct used_atom *atom, const char *arg)
205 {
206         if (!arg)
207                 atom->u.objectname.option = O_FULL;
208         else if (!strcmp(arg, "short"))
209                 atom->u.objectname.option = O_SHORT;
210         else if (skip_prefix(arg, "short=", &arg)) {
211                 atom->u.objectname.option = O_LENGTH;
212                 if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
213                     atom->u.objectname.length == 0)
214                         die(_("positive value expected objectname:short=%s"), arg);
215                 if (atom->u.objectname.length < MINIMUM_ABBREV)
216                         atom->u.objectname.length = MINIMUM_ABBREV;
217         } else
218                 die(_("unrecognized %%(objectname) argument: %s"), arg);
219 }
220
221 static void refname_atom_parser(struct used_atom *atom, const char *arg)
222 {
223         return refname_atom_parser_internal(&atom->u.refname, arg, atom->name);
224 }
225
226 static align_type parse_align_position(const char *s)
227 {
228         if (!strcmp(s, "right"))
229                 return ALIGN_RIGHT;
230         else if (!strcmp(s, "middle"))
231                 return ALIGN_MIDDLE;
232         else if (!strcmp(s, "left"))
233                 return ALIGN_LEFT;
234         return -1;
235 }
236
237 static void align_atom_parser(struct used_atom *atom, const char *arg)
238 {
239         struct align *align = &atom->u.align;
240         struct string_list params = STRING_LIST_INIT_DUP;
241         int i;
242         unsigned int width = ~0U;
243
244         if (!arg)
245                 die(_("expected format: %%(align:<width>,<position>)"));
246
247         align->position = ALIGN_LEFT;
248
249         string_list_split(&params, arg, ',', -1);
250         for (i = 0; i < params.nr; i++) {
251                 const char *s = params.items[i].string;
252                 int position;
253
254                 if (skip_prefix(s, "position=", &s)) {
255                         position = parse_align_position(s);
256                         if (position < 0)
257                                 die(_("unrecognized position:%s"), s);
258                         align->position = position;
259                 } else if (skip_prefix(s, "width=", &s)) {
260                         if (strtoul_ui(s, 10, &width))
261                                 die(_("unrecognized width:%s"), s);
262                 } else if (!strtoul_ui(s, 10, &width))
263                         ;
264                 else if ((position = parse_align_position(s)) >= 0)
265                         align->position = position;
266                 else
267                         die(_("unrecognized %%(align) argument: %s"), s);
268         }
269
270         if (width == ~0U)
271                 die(_("positive width expected with the %%(align) atom"));
272         align->width = width;
273         string_list_clear(&params, 0);
274 }
275
276 static void if_atom_parser(struct used_atom *atom, const char *arg)
277 {
278         if (!arg) {
279                 atom->u.if_then_else.cmp_status = COMPARE_NONE;
280                 return;
281         } else if (skip_prefix(arg, "equals=", &atom->u.if_then_else.str)) {
282                 atom->u.if_then_else.cmp_status = COMPARE_EQUAL;
283         } else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
284                 atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
285         } else {
286                 die(_("unrecognized %%(if) argument: %s"), arg);
287         }
288 }
289
290 static void head_atom_parser(struct used_atom *atom, const char *arg)
291 {
292         unsigned char unused[GIT_SHA1_RAWSZ];
293
294         atom->u.head = resolve_refdup("HEAD", RESOLVE_REF_READING, unused, NULL);
295 }
296
297 static struct {
298         const char *name;
299         cmp_type cmp_type;
300         void (*parser)(struct used_atom *atom, const char *arg);
301 } valid_atom[] = {
302         { "refname" , FIELD_STR, refname_atom_parser },
303         { "objecttype" },
304         { "objectsize", FIELD_ULONG },
305         { "objectname", FIELD_STR, objectname_atom_parser },
306         { "tree" },
307         { "parent" },
308         { "numparent", FIELD_ULONG },
309         { "object" },
310         { "type" },
311         { "tag" },
312         { "author" },
313         { "authorname" },
314         { "authoremail" },
315         { "authordate", FIELD_TIME },
316         { "committer" },
317         { "committername" },
318         { "committeremail" },
319         { "committerdate", FIELD_TIME },
320         { "tagger" },
321         { "taggername" },
322         { "taggeremail" },
323         { "taggerdate", FIELD_TIME },
324         { "creator" },
325         { "creatordate", FIELD_TIME },
326         { "subject", FIELD_STR, subject_atom_parser },
327         { "body", FIELD_STR, body_atom_parser },
328         { "trailers", FIELD_STR, trailers_atom_parser },
329         { "contents", FIELD_STR, contents_atom_parser },
330         { "upstream", FIELD_STR, remote_ref_atom_parser },
331         { "push", FIELD_STR, remote_ref_atom_parser },
332         { "symref", FIELD_STR, refname_atom_parser },
333         { "flag" },
334         { "HEAD", FIELD_STR, head_atom_parser },
335         { "color", FIELD_STR, color_atom_parser },
336         { "align", FIELD_STR, align_atom_parser },
337         { "end" },
338         { "if", FIELD_STR, if_atom_parser },
339         { "then" },
340         { "else" },
341 };
342
343 #define REF_FORMATTING_STATE_INIT  { 0, NULL }
344
345 struct ref_formatting_stack {
346         struct ref_formatting_stack *prev;
347         struct strbuf output;
348         void (*at_end)(struct ref_formatting_stack **stack);
349         void *at_end_data;
350 };
351
352 struct ref_formatting_state {
353         int quote_style;
354         struct ref_formatting_stack *stack;
355 };
356
357 struct atom_value {
358         const char *s;
359         void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
360         unsigned long ul; /* used for sorting when not FIELD_STR */
361         struct used_atom *atom;
362 };
363
364 /*
365  * Used to parse format string and sort specifiers
366  */
367 int parse_ref_filter_atom(const char *atom, const char *ep)
368 {
369         const char *sp;
370         const char *arg;
371         int i, at, atom_len;
372
373         sp = atom;
374         if (*sp == '*' && sp < ep)
375                 sp++; /* deref */
376         if (ep <= sp)
377                 die(_("malformed field name: %.*s"), (int)(ep-atom), atom);
378
379         /* Do we have the atom already used elsewhere? */
380         for (i = 0; i < used_atom_cnt; i++) {
381                 int len = strlen(used_atom[i].name);
382                 if (len == ep - atom && !memcmp(used_atom[i].name, atom, len))
383                         return i;
384         }
385
386         /*
387          * If the atom name has a colon, strip it and everything after
388          * it off - it specifies the format for this entry, and
389          * shouldn't be used for checking against the valid_atom
390          * table.
391          */
392         arg = memchr(sp, ':', ep - sp);
393         atom_len = (arg ? arg : ep) - sp;
394
395         /* Is the atom a valid one? */
396         for (i = 0; i < ARRAY_SIZE(valid_atom); i++) {
397                 int len = strlen(valid_atom[i].name);
398                 if (len == atom_len && !memcmp(valid_atom[i].name, sp, len))
399                         break;
400         }
401
402         if (ARRAY_SIZE(valid_atom) <= i)
403                 die(_("unknown field name: %.*s"), (int)(ep-atom), atom);
404
405         /* Add it in, including the deref prefix */
406         at = used_atom_cnt;
407         used_atom_cnt++;
408         REALLOC_ARRAY(used_atom, used_atom_cnt);
409         used_atom[at].name = xmemdupz(atom, ep - atom);
410         used_atom[at].type = valid_atom[i].cmp_type;
411         if (arg)
412                 arg = used_atom[at].name + (arg - atom) + 1;
413         memset(&used_atom[at].u, 0, sizeof(used_atom[at].u));
414         if (valid_atom[i].parser)
415                 valid_atom[i].parser(&used_atom[at], arg);
416         if (*atom == '*')
417                 need_tagged = 1;
418         if (!strcmp(valid_atom[i].name, "symref"))
419                 need_symref = 1;
420         return at;
421 }
422
423 static void quote_formatting(struct strbuf *s, const char *str, int quote_style)
424 {
425         switch (quote_style) {
426         case QUOTE_NONE:
427                 strbuf_addstr(s, str);
428                 break;
429         case QUOTE_SHELL:
430                 sq_quote_buf(s, str);
431                 break;
432         case QUOTE_PERL:
433                 perl_quote_buf(s, str);
434                 break;
435         case QUOTE_PYTHON:
436                 python_quote_buf(s, str);
437                 break;
438         case QUOTE_TCL:
439                 tcl_quote_buf(s, str);
440                 break;
441         }
442 }
443
444 static void append_atom(struct atom_value *v, struct ref_formatting_state *state)
445 {
446         /*
447          * Quote formatting is only done when the stack has a single
448          * element. Otherwise quote formatting is done on the
449          * element's entire output strbuf when the %(end) atom is
450          * encountered.
451          */
452         if (!state->stack->prev)
453                 quote_formatting(&state->stack->output, v->s, state->quote_style);
454         else
455                 strbuf_addstr(&state->stack->output, v->s);
456 }
457
458 static void push_stack_element(struct ref_formatting_stack **stack)
459 {
460         struct ref_formatting_stack *s = xcalloc(1, sizeof(struct ref_formatting_stack));
461
462         strbuf_init(&s->output, 0);
463         s->prev = *stack;
464         *stack = s;
465 }
466
467 static void pop_stack_element(struct ref_formatting_stack **stack)
468 {
469         struct ref_formatting_stack *current = *stack;
470         struct ref_formatting_stack *prev = current->prev;
471
472         if (prev)
473                 strbuf_addbuf(&prev->output, &current->output);
474         strbuf_release(&current->output);
475         free(current);
476         *stack = prev;
477 }
478
479 static void end_align_handler(struct ref_formatting_stack **stack)
480 {
481         struct ref_formatting_stack *cur = *stack;
482         struct align *align = (struct align *)cur->at_end_data;
483         struct strbuf s = STRBUF_INIT;
484
485         strbuf_utf8_align(&s, align->position, align->width, cur->output.buf);
486         strbuf_swap(&cur->output, &s);
487         strbuf_release(&s);
488 }
489
490 static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
491 {
492         struct ref_formatting_stack *new;
493
494         push_stack_element(&state->stack);
495         new = state->stack;
496         new->at_end = end_align_handler;
497         new->at_end_data = &atomv->atom->u.align;
498 }
499
500 static void if_then_else_handler(struct ref_formatting_stack **stack)
501 {
502         struct ref_formatting_stack *cur = *stack;
503         struct ref_formatting_stack *prev = cur->prev;
504         struct if_then_else *if_then_else = (struct if_then_else *)cur->at_end_data;
505
506         if (!if_then_else->then_atom_seen)
507                 die(_("format: %%(if) atom used without a %%(then) atom"));
508
509         if (if_then_else->else_atom_seen) {
510                 /*
511                  * There is an %(else) atom: we need to drop one state from the
512                  * stack, either the %(else) branch if the condition is satisfied, or
513                  * the %(then) branch if it isn't.
514                  */
515                 if (if_then_else->condition_satisfied) {
516                         strbuf_reset(&cur->output);
517                         pop_stack_element(&cur);
518                 } else {
519                         strbuf_swap(&cur->output, &prev->output);
520                         strbuf_reset(&cur->output);
521                         pop_stack_element(&cur);
522                 }
523         } else if (!if_then_else->condition_satisfied) {
524                 /*
525                  * No %(else) atom: just drop the %(then) branch if the
526                  * condition is not satisfied.
527                  */
528                 strbuf_reset(&cur->output);
529         }
530
531         *stack = cur;
532         free(if_then_else);
533 }
534
535 static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
536 {
537         struct ref_formatting_stack *new;
538         struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
539
540         if_then_else->str = atomv->atom->u.if_then_else.str;
541         if_then_else->cmp_status = atomv->atom->u.if_then_else.cmp_status;
542
543         push_stack_element(&state->stack);
544         new = state->stack;
545         new->at_end = if_then_else_handler;
546         new->at_end_data = if_then_else;
547 }
548
549 static int is_empty(const char *s)
550 {
551         while (*s != '\0') {
552                 if (!isspace(*s))
553                         return 0;
554                 s++;
555         }
556         return 1;
557 }
558
559 static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
560 {
561         struct ref_formatting_stack *cur = state->stack;
562         struct if_then_else *if_then_else = NULL;
563
564         if (cur->at_end == if_then_else_handler)
565                 if_then_else = (struct if_then_else *)cur->at_end_data;
566         if (!if_then_else)
567                 die(_("format: %%(then) atom used without an %%(if) atom"));
568         if (if_then_else->then_atom_seen)
569                 die(_("format: %%(then) atom used more than once"));
570         if (if_then_else->else_atom_seen)
571                 die(_("format: %%(then) atom used after %%(else)"));
572         if_then_else->then_atom_seen = 1;
573         /*
574          * If the 'equals' or 'notequals' attribute is used then
575          * perform the required comparison. If not, only non-empty
576          * strings satisfy the 'if' condition.
577          */
578         if (if_then_else->cmp_status == COMPARE_EQUAL) {
579                 if (!strcmp(if_then_else->str, cur->output.buf))
580                         if_then_else->condition_satisfied = 1;
581         } else if (if_then_else->cmp_status == COMPARE_UNEQUAL) {
582                 if (strcmp(if_then_else->str, cur->output.buf))
583                         if_then_else->condition_satisfied = 1;
584         } else if (cur->output.len && !is_empty(cur->output.buf))
585                 if_then_else->condition_satisfied = 1;
586         strbuf_reset(&cur->output);
587 }
588
589 static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
590 {
591         struct ref_formatting_stack *prev = state->stack;
592         struct if_then_else *if_then_else = NULL;
593
594         if (prev->at_end == if_then_else_handler)
595                 if_then_else = (struct if_then_else *)prev->at_end_data;
596         if (!if_then_else)
597                 die(_("format: %%(else) atom used without an %%(if) atom"));
598         if (!if_then_else->then_atom_seen)
599                 die(_("format: %%(else) atom used without a %%(then) atom"));
600         if (if_then_else->else_atom_seen)
601                 die(_("format: %%(else) atom used more than once"));
602         if_then_else->else_atom_seen = 1;
603         push_stack_element(&state->stack);
604         state->stack->at_end_data = prev->at_end_data;
605         state->stack->at_end = prev->at_end;
606 }
607
608 static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
609 {
610         struct ref_formatting_stack *current = state->stack;
611         struct strbuf s = STRBUF_INIT;
612
613         if (!current->at_end)
614                 die(_("format: %%(end) atom used without corresponding atom"));
615         current->at_end(&state->stack);
616
617         /*  Stack may have been popped within at_end(), hence reset the current pointer */
618         current = state->stack;
619
620         /*
621          * Perform quote formatting when the stack element is that of
622          * a supporting atom. If nested then perform quote formatting
623          * only on the topmost supporting atom.
624          */
625         if (!current->prev->prev) {
626                 quote_formatting(&s, current->output.buf, state->quote_style);
627                 strbuf_swap(&current->output, &s);
628         }
629         strbuf_release(&s);
630         pop_stack_element(&state->stack);
631 }
632
633 /*
634  * In a format string, find the next occurrence of %(atom).
635  */
636 static const char *find_next(const char *cp)
637 {
638         while (*cp) {
639                 if (*cp == '%') {
640                         /*
641                          * %( is the start of an atom;
642                          * %% is a quoted per-cent.
643                          */
644                         if (cp[1] == '(')
645                                 return cp;
646                         else if (cp[1] == '%')
647                                 cp++; /* skip over two % */
648                         /* otherwise this is a singleton, literal % */
649                 }
650                 cp++;
651         }
652         return NULL;
653 }
654
655 /*
656  * Make sure the format string is well formed, and parse out
657  * the used atoms.
658  */
659 int verify_ref_format(const char *format)
660 {
661         const char *cp, *sp;
662
663         need_color_reset_at_eol = 0;
664         for (cp = format; *cp && (sp = find_next(cp)); ) {
665                 const char *color, *ep = strchr(sp, ')');
666                 int at;
667
668                 if (!ep)
669                         return error(_("malformed format string %s"), sp);
670                 /* sp points at "%(" and ep points at the closing ")" */
671                 at = parse_ref_filter_atom(sp + 2, ep);
672                 cp = ep + 1;
673
674                 if (skip_prefix(used_atom[at].name, "color:", &color))
675                         need_color_reset_at_eol = !!strcmp(color, "reset");
676         }
677         return 0;
678 }
679
680 /*
681  * Given an object name, read the object data and size, and return a
682  * "struct object".  If the object data we are returning is also borrowed
683  * by the "struct object" representation, set *eaten as well---it is a
684  * signal from parse_object_buffer to us not to free the buffer.
685  */
686 static void *get_obj(const unsigned char *sha1, struct object **obj, unsigned long *sz, int *eaten)
687 {
688         enum object_type type;
689         void *buf = read_sha1_file(sha1, &type, sz);
690
691         if (buf)
692                 *obj = parse_object_buffer(sha1, type, *sz, buf, eaten);
693         else
694                 *obj = NULL;
695         return buf;
696 }
697
698 static int grab_objectname(const char *name, const unsigned char *sha1,
699                            struct atom_value *v, struct used_atom *atom)
700 {
701         if (starts_with(name, "objectname")) {
702                 if (atom->u.objectname.option == O_SHORT) {
703                         v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
704                         return 1;
705                 } else if (atom->u.objectname.option == O_FULL) {
706                         v->s = xstrdup(sha1_to_hex(sha1));
707                         return 1;
708                 } else if (atom->u.objectname.option == O_LENGTH) {
709                         v->s = xstrdup(find_unique_abbrev(sha1, atom->u.objectname.length));
710                         return 1;
711                 } else
712                         die("BUG: unknown %%(objectname) option");
713         }
714         return 0;
715 }
716
717 /* See grab_values */
718 static void grab_common_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
719 {
720         int i;
721
722         for (i = 0; i < used_atom_cnt; i++) {
723                 const char *name = used_atom[i].name;
724                 struct atom_value *v = &val[i];
725                 if (!!deref != (*name == '*'))
726                         continue;
727                 if (deref)
728                         name++;
729                 if (!strcmp(name, "objecttype"))
730                         v->s = typename(obj->type);
731                 else if (!strcmp(name, "objectsize")) {
732                         v->ul = sz;
733                         v->s = xstrfmt("%lu", sz);
734                 }
735                 else if (deref)
736                         grab_objectname(name, obj->oid.hash, v, &used_atom[i]);
737         }
738 }
739
740 /* See grab_values */
741 static void grab_tag_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
742 {
743         int i;
744         struct tag *tag = (struct tag *) obj;
745
746         for (i = 0; i < used_atom_cnt; i++) {
747                 const char *name = used_atom[i].name;
748                 struct atom_value *v = &val[i];
749                 if (!!deref != (*name == '*'))
750                         continue;
751                 if (deref)
752                         name++;
753                 if (!strcmp(name, "tag"))
754                         v->s = tag->tag;
755                 else if (!strcmp(name, "type") && tag->tagged)
756                         v->s = typename(tag->tagged->type);
757                 else if (!strcmp(name, "object") && tag->tagged)
758                         v->s = xstrdup(oid_to_hex(&tag->tagged->oid));
759         }
760 }
761
762 /* See grab_values */
763 static void grab_commit_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
764 {
765         int i;
766         struct commit *commit = (struct commit *) obj;
767
768         for (i = 0; i < used_atom_cnt; i++) {
769                 const char *name = used_atom[i].name;
770                 struct atom_value *v = &val[i];
771                 if (!!deref != (*name == '*'))
772                         continue;
773                 if (deref)
774                         name++;
775                 if (!strcmp(name, "tree")) {
776                         v->s = xstrdup(oid_to_hex(&commit->tree->object.oid));
777                 }
778                 else if (!strcmp(name, "numparent")) {
779                         v->ul = commit_list_count(commit->parents);
780                         v->s = xstrfmt("%lu", v->ul);
781                 }
782                 else if (!strcmp(name, "parent")) {
783                         struct commit_list *parents;
784                         struct strbuf s = STRBUF_INIT;
785                         for (parents = commit->parents; parents; parents = parents->next) {
786                                 struct commit *parent = parents->item;
787                                 if (parents != commit->parents)
788                                         strbuf_addch(&s, ' ');
789                                 strbuf_addstr(&s, oid_to_hex(&parent->object.oid));
790                         }
791                         v->s = strbuf_detach(&s, NULL);
792                 }
793         }
794 }
795
796 static const char *find_wholine(const char *who, int wholen, const char *buf, unsigned long sz)
797 {
798         const char *eol;
799         while (*buf) {
800                 if (!strncmp(buf, who, wholen) &&
801                     buf[wholen] == ' ')
802                         return buf + wholen + 1;
803                 eol = strchr(buf, '\n');
804                 if (!eol)
805                         return "";
806                 eol++;
807                 if (*eol == '\n')
808                         return ""; /* end of header */
809                 buf = eol;
810         }
811         return "";
812 }
813
814 static const char *copy_line(const char *buf)
815 {
816         const char *eol = strchrnul(buf, '\n');
817         return xmemdupz(buf, eol - buf);
818 }
819
820 static const char *copy_name(const char *buf)
821 {
822         const char *cp;
823         for (cp = buf; *cp && *cp != '\n'; cp++) {
824                 if (!strncmp(cp, " <", 2))
825                         return xmemdupz(buf, cp - buf);
826         }
827         return "";
828 }
829
830 static const char *copy_email(const char *buf)
831 {
832         const char *email = strchr(buf, '<');
833         const char *eoemail;
834         if (!email)
835                 return "";
836         eoemail = strchr(email, '>');
837         if (!eoemail)
838                 return "";
839         return xmemdupz(email, eoemail + 1 - email);
840 }
841
842 static char *copy_subject(const char *buf, unsigned long len)
843 {
844         char *r = xmemdupz(buf, len);
845         int i;
846
847         for (i = 0; i < len; i++)
848                 if (r[i] == '\n')
849                         r[i] = ' ';
850
851         return r;
852 }
853
854 static void grab_date(const char *buf, struct atom_value *v, const char *atomname)
855 {
856         const char *eoemail = strstr(buf, "> ");
857         char *zone;
858         unsigned long timestamp;
859         long tz;
860         struct date_mode date_mode = { DATE_NORMAL };
861         const char *formatp;
862
863         /*
864          * We got here because atomname ends in "date" or "date<something>";
865          * it's not possible that <something> is not ":<format>" because
866          * parse_ref_filter_atom() wouldn't have allowed it, so we can assume that no
867          * ":" means no format is specified, and use the default.
868          */
869         formatp = strchr(atomname, ':');
870         if (formatp != NULL) {
871                 formatp++;
872                 parse_date_format(formatp, &date_mode);
873         }
874
875         if (!eoemail)
876                 goto bad;
877         timestamp = strtoul(eoemail + 2, &zone, 10);
878         if (timestamp == ULONG_MAX)
879                 goto bad;
880         tz = strtol(zone, NULL, 10);
881         if ((tz == LONG_MIN || tz == LONG_MAX) && errno == ERANGE)
882                 goto bad;
883         v->s = xstrdup(show_date(timestamp, tz, &date_mode));
884         v->ul = timestamp;
885         return;
886  bad:
887         v->s = "";
888         v->ul = 0;
889 }
890
891 /* See grab_values */
892 static void grab_person(const char *who, struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
893 {
894         int i;
895         int wholen = strlen(who);
896         const char *wholine = NULL;
897
898         for (i = 0; i < used_atom_cnt; i++) {
899                 const char *name = used_atom[i].name;
900                 struct atom_value *v = &val[i];
901                 if (!!deref != (*name == '*'))
902                         continue;
903                 if (deref)
904                         name++;
905                 if (strncmp(who, name, wholen))
906                         continue;
907                 if (name[wholen] != 0 &&
908                     strcmp(name + wholen, "name") &&
909                     strcmp(name + wholen, "email") &&
910                     !starts_with(name + wholen, "date"))
911                         continue;
912                 if (!wholine)
913                         wholine = find_wholine(who, wholen, buf, sz);
914                 if (!wholine)
915                         return; /* no point looking for it */
916                 if (name[wholen] == 0)
917                         v->s = copy_line(wholine);
918                 else if (!strcmp(name + wholen, "name"))
919                         v->s = copy_name(wholine);
920                 else if (!strcmp(name + wholen, "email"))
921                         v->s = copy_email(wholine);
922                 else if (starts_with(name + wholen, "date"))
923                         grab_date(wholine, v, name);
924         }
925
926         /*
927          * For a tag or a commit object, if "creator" or "creatordate" is
928          * requested, do something special.
929          */
930         if (strcmp(who, "tagger") && strcmp(who, "committer"))
931                 return; /* "author" for commit object is not wanted */
932         if (!wholine)
933                 wholine = find_wholine(who, wholen, buf, sz);
934         if (!wholine)
935                 return;
936         for (i = 0; i < used_atom_cnt; i++) {
937                 const char *name = used_atom[i].name;
938                 struct atom_value *v = &val[i];
939                 if (!!deref != (*name == '*'))
940                         continue;
941                 if (deref)
942                         name++;
943
944                 if (starts_with(name, "creatordate"))
945                         grab_date(wholine, v, name);
946                 else if (!strcmp(name, "creator"))
947                         v->s = copy_line(wholine);
948         }
949 }
950
951 static void find_subpos(const char *buf, unsigned long sz,
952                         const char **sub, unsigned long *sublen,
953                         const char **body, unsigned long *bodylen,
954                         unsigned long *nonsiglen,
955                         const char **sig, unsigned long *siglen)
956 {
957         const char *eol;
958         /* skip past header until we hit empty line */
959         while (*buf && *buf != '\n') {
960                 eol = strchrnul(buf, '\n');
961                 if (*eol)
962                         eol++;
963                 buf = eol;
964         }
965         /* skip any empty lines */
966         while (*buf == '\n')
967                 buf++;
968
969         /* parse signature first; we might not even have a subject line */
970         *sig = buf + parse_signature(buf, strlen(buf));
971         *siglen = strlen(*sig);
972
973         /* subject is first non-empty line */
974         *sub = buf;
975         /* subject goes to first empty line */
976         while (buf < *sig && *buf && *buf != '\n') {
977                 eol = strchrnul(buf, '\n');
978                 if (*eol)
979                         eol++;
980                 buf = eol;
981         }
982         *sublen = buf - *sub;
983         /* drop trailing newline, if present */
984         if (*sublen && (*sub)[*sublen - 1] == '\n')
985                 *sublen -= 1;
986
987         /* skip any empty lines */
988         while (*buf == '\n')
989                 buf++;
990         *body = buf;
991         *bodylen = strlen(buf);
992         *nonsiglen = *sig - buf;
993 }
994
995 /*
996  * If 'lines' is greater than 0, append that many lines from the given
997  * 'buf' of length 'size' to the given strbuf.
998  */
999 static void append_lines(struct strbuf *out, const char *buf, unsigned long size, int lines)
1000 {
1001         int i;
1002         const char *sp, *eol;
1003         size_t len;
1004
1005         sp = buf;
1006
1007         for (i = 0; i < lines && sp < buf + size; i++) {
1008                 if (i)
1009                         strbuf_addstr(out, "\n    ");
1010                 eol = memchr(sp, '\n', size - (sp - buf));
1011                 len = eol ? eol - sp : size - (sp - buf);
1012                 strbuf_add(out, sp, len);
1013                 if (!eol)
1014                         break;
1015                 sp = eol + 1;
1016         }
1017 }
1018
1019 /* See grab_values */
1020 static void grab_sub_body_contents(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
1021 {
1022         int i;
1023         const char *subpos = NULL, *bodypos = NULL, *sigpos = NULL;
1024         unsigned long sublen = 0, bodylen = 0, nonsiglen = 0, siglen = 0;
1025
1026         for (i = 0; i < used_atom_cnt; i++) {
1027                 struct used_atom *atom = &used_atom[i];
1028                 const char *name = atom->name;
1029                 struct atom_value *v = &val[i];
1030                 if (!!deref != (*name == '*'))
1031                         continue;
1032                 if (deref)
1033                         name++;
1034                 if (strcmp(name, "subject") &&
1035                     strcmp(name, "body") &&
1036                     strcmp(name, "trailers") &&
1037                     !starts_with(name, "contents"))
1038                         continue;
1039                 if (!subpos)
1040                         find_subpos(buf, sz,
1041                                     &subpos, &sublen,
1042                                     &bodypos, &bodylen, &nonsiglen,
1043                                     &sigpos, &siglen);
1044
1045                 if (atom->u.contents.option == C_SUB)
1046                         v->s = copy_subject(subpos, sublen);
1047                 else if (atom->u.contents.option == C_BODY_DEP)
1048                         v->s = xmemdupz(bodypos, bodylen);
1049                 else if (atom->u.contents.option == C_BODY)
1050                         v->s = xmemdupz(bodypos, nonsiglen);
1051                 else if (atom->u.contents.option == C_SIG)
1052                         v->s = xmemdupz(sigpos, siglen);
1053                 else if (atom->u.contents.option == C_LINES) {
1054                         struct strbuf s = STRBUF_INIT;
1055                         const char *contents_end = bodylen + bodypos - siglen;
1056
1057                         /*  Size is the length of the message after removing the signature */
1058                         append_lines(&s, subpos, contents_end - subpos, atom->u.contents.nlines);
1059                         v->s = strbuf_detach(&s, NULL);
1060                 } else if (atom->u.contents.option == C_TRAILERS) {
1061                         struct trailer_info info;
1062
1063                         /* Search for trailer info */
1064                         trailer_info_get(&info, subpos);
1065                         v->s = xmemdupz(info.trailer_start,
1066                                         info.trailer_end - info.trailer_start);
1067                         trailer_info_release(&info);
1068                 } else if (atom->u.contents.option == C_BARE)
1069                         v->s = xstrdup(subpos);
1070         }
1071 }
1072
1073 /*
1074  * We want to have empty print-string for field requests
1075  * that do not apply (e.g. "authordate" for a tag object)
1076  */
1077 static void fill_missing_values(struct atom_value *val)
1078 {
1079         int i;
1080         for (i = 0; i < used_atom_cnt; i++) {
1081                 struct atom_value *v = &val[i];
1082                 if (v->s == NULL)
1083                         v->s = "";
1084         }
1085 }
1086
1087 /*
1088  * val is a list of atom_value to hold returned values.  Extract
1089  * the values for atoms in used_atom array out of (obj, buf, sz).
1090  * when deref is false, (obj, buf, sz) is the object that is
1091  * pointed at by the ref itself; otherwise it is the object the
1092  * ref (which is a tag) refers to.
1093  */
1094 static void grab_values(struct atom_value *val, int deref, struct object *obj, void *buf, unsigned long sz)
1095 {
1096         grab_common_values(val, deref, obj, buf, sz);
1097         switch (obj->type) {
1098         case OBJ_TAG:
1099                 grab_tag_values(val, deref, obj, buf, sz);
1100                 grab_sub_body_contents(val, deref, obj, buf, sz);
1101                 grab_person("tagger", val, deref, obj, buf, sz);
1102                 break;
1103         case OBJ_COMMIT:
1104                 grab_commit_values(val, deref, obj, buf, sz);
1105                 grab_sub_body_contents(val, deref, obj, buf, sz);
1106                 grab_person("author", val, deref, obj, buf, sz);
1107                 grab_person("committer", val, deref, obj, buf, sz);
1108                 break;
1109         case OBJ_TREE:
1110                 /* grab_tree_values(val, deref, obj, buf, sz); */
1111                 break;
1112         case OBJ_BLOB:
1113                 /* grab_blob_values(val, deref, obj, buf, sz); */
1114                 break;
1115         default:
1116                 die("Eh?  Object of type %d?", obj->type);
1117         }
1118 }
1119
1120 static inline char *copy_advance(char *dst, const char *src)
1121 {
1122         while (*src)
1123                 *dst++ = *src++;
1124         return dst;
1125 }
1126
1127 static const char *lstrip_ref_components(const char *refname, int len)
1128 {
1129         long remaining = len;
1130         const char *start = refname;
1131
1132         if (len < 0) {
1133                 int i;
1134                 const char *p = refname;
1135
1136                 /* Find total no of '/' separated path-components */
1137                 for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
1138                         ;
1139                 /*
1140                  * The number of components we need to strip is now
1141                  * the total minus the components to be left (Plus one
1142                  * because we count the number of '/', but the number
1143                  * of components is one more than the no of '/').
1144                  */
1145                 remaining = i + len + 1;
1146         }
1147
1148         while (remaining > 0) {
1149                 switch (*start++) {
1150                 case '\0':
1151                         return "";
1152                 case '/':
1153                         remaining--;
1154                         break;
1155                 }
1156         }
1157
1158         return start;
1159 }
1160
1161 static const char *rstrip_ref_components(const char *refname, int len)
1162 {
1163         long remaining = len;
1164         char *start = xstrdup(refname);
1165
1166         if (len < 0) {
1167                 int i;
1168                 const char *p = refname;
1169
1170                 /* Find total no of '/' separated path-components */
1171                 for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
1172                         ;
1173                 /*
1174                  * The number of components we need to strip is now
1175                  * the total minus the components to be left (Plus one
1176                  * because we count the number of '/', but the number
1177                  * of components is one more than the no of '/').
1178                  */
1179                 remaining = i + len + 1;
1180         }
1181
1182         while (remaining-- > 0) {
1183                 char *p = strrchr(start, '/');
1184                 if (p == NULL)
1185                         return "";
1186                 else
1187                         p[0] = '\0';
1188         }
1189         return start;
1190 }
1191
1192 static const char *show_ref(struct refname_atom *atom, const char *refname)
1193 {
1194         if (atom->option == R_SHORT)
1195                 return shorten_unambiguous_ref(refname, warn_ambiguous_refs);
1196         else if (atom->option == R_LSTRIP)
1197                 return lstrip_ref_components(refname, atom->lstrip);
1198         else if (atom->option == R_RSTRIP)
1199                 return rstrip_ref_components(refname, atom->rstrip);
1200         else
1201                 return refname;
1202 }
1203
1204 static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
1205                                     struct branch *branch, const char **s)
1206 {
1207         int num_ours, num_theirs;
1208         if (atom->u.remote_ref.option == RR_REF)
1209                 *s = show_ref(&atom->u.remote_ref.refname, refname);
1210         else if (atom->u.remote_ref.option == RR_TRACK) {
1211                 if (stat_tracking_info(branch, &num_ours,
1212                                        &num_theirs, NULL)) {
1213                         *s = xstrdup(msgs.gone);
1214                 } else if (!num_ours && !num_theirs)
1215                         *s = "";
1216                 else if (!num_ours)
1217                         *s = xstrfmt(msgs.behind, num_theirs);
1218                 else if (!num_theirs)
1219                         *s = xstrfmt(msgs.ahead, num_ours);
1220                 else
1221                         *s = xstrfmt(msgs.ahead_behind,
1222                                      num_ours, num_theirs);
1223                 if (!atom->u.remote_ref.nobracket && *s[0]) {
1224                         const char *to_free = *s;
1225                         *s = xstrfmt("[%s]", *s);
1226                         free((void *)to_free);
1227                 }
1228         } else if (atom->u.remote_ref.option == RR_TRACKSHORT) {
1229                 if (stat_tracking_info(branch, &num_ours,
1230                                        &num_theirs, NULL))
1231                         return;
1232
1233                 if (!num_ours && !num_theirs)
1234                         *s = "=";
1235                 else if (!num_ours)
1236                         *s = "<";
1237                 else if (!num_theirs)
1238                         *s = ">";
1239                 else
1240                         *s = "<>";
1241         } else
1242                 die("BUG: unhandled RR_* enum");
1243 }
1244
1245 char *get_head_description(void)
1246 {
1247         struct strbuf desc = STRBUF_INIT;
1248         struct wt_status_state state;
1249         memset(&state, 0, sizeof(state));
1250         wt_status_get_state(&state, 1);
1251         if (state.rebase_in_progress ||
1252             state.rebase_interactive_in_progress)
1253                 strbuf_addf(&desc, _("(no branch, rebasing %s)"),
1254                             state.branch);
1255         else if (state.bisect_in_progress)
1256                 strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
1257                             state.branch);
1258         else if (state.detached_from) {
1259                 /* TRANSLATORS: make sure these match _("HEAD detached at ")
1260                    and _("HEAD detached from ") in wt-status.c */
1261                 if (state.detached_at)
1262                         strbuf_addf(&desc, _("(HEAD detached at %s)"),
1263                                 state.detached_from);
1264                 else
1265                         strbuf_addf(&desc, _("(HEAD detached from %s)"),
1266                                 state.detached_from);
1267         }
1268         else
1269                 strbuf_addstr(&desc, _("(no branch)"));
1270         free(state.branch);
1271         free(state.onto);
1272         free(state.detached_from);
1273         return strbuf_detach(&desc, NULL);
1274 }
1275
1276 static const char *get_symref(struct used_atom *atom, struct ref_array_item *ref)
1277 {
1278         if (!ref->symref)
1279                 return "";
1280         else
1281                 return show_ref(&atom->u.refname, ref->symref);
1282 }
1283
1284 static const char *get_refname(struct used_atom *atom, struct ref_array_item *ref)
1285 {
1286         if (ref->kind & FILTER_REFS_DETACHED_HEAD)
1287                 return get_head_description();
1288         return show_ref(&atom->u.refname, ref->refname);
1289 }
1290
1291 /*
1292  * Parse the object referred by ref, and grab needed value.
1293  */
1294 static void populate_value(struct ref_array_item *ref)
1295 {
1296         void *buf;
1297         struct object *obj;
1298         int eaten, i;
1299         unsigned long size;
1300         const unsigned char *tagged;
1301
1302         ref->value = xcalloc(used_atom_cnt, sizeof(struct atom_value));
1303
1304         if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
1305                 unsigned char unused1[20];
1306                 ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
1307                                              unused1, NULL);
1308                 if (!ref->symref)
1309                         ref->symref = "";
1310         }
1311
1312         /* Fill in specials first */
1313         for (i = 0; i < used_atom_cnt; i++) {
1314                 struct used_atom *atom = &used_atom[i];
1315                 const char *name = used_atom[i].name;
1316                 struct atom_value *v = &ref->value[i];
1317                 int deref = 0;
1318                 const char *refname;
1319                 struct branch *branch = NULL;
1320
1321                 v->handler = append_atom;
1322                 v->atom = atom;
1323
1324                 if (*name == '*') {
1325                         deref = 1;
1326                         name++;
1327                 }
1328
1329                 if (starts_with(name, "refname"))
1330                         refname = get_refname(atom, ref);
1331                 else if (starts_with(name, "symref"))
1332                         refname = get_symref(atom, ref);
1333                 else if (starts_with(name, "upstream")) {
1334                         const char *branch_name;
1335                         /* only local branches may have an upstream */
1336                         if (!skip_prefix(ref->refname, "refs/heads/",
1337                                          &branch_name))
1338                                 continue;
1339                         branch = branch_get(branch_name);
1340
1341                         refname = branch_get_upstream(branch, NULL);
1342                         if (refname)
1343                                 fill_remote_ref_details(atom, refname, branch, &v->s);
1344                         continue;
1345                 } else if (starts_with(name, "push")) {
1346                         const char *branch_name;
1347                         if (!skip_prefix(ref->refname, "refs/heads/",
1348                                          &branch_name))
1349                                 continue;
1350                         branch = branch_get(branch_name);
1351
1352                         refname = branch_get_push(branch, NULL);
1353                         if (!refname)
1354                                 continue;
1355                         fill_remote_ref_details(atom, refname, branch, &v->s);
1356                         continue;
1357                 } else if (starts_with(name, "color:")) {
1358                         v->s = atom->u.color;
1359                         continue;
1360                 } else if (!strcmp(name, "flag")) {
1361                         char buf[256], *cp = buf;
1362                         if (ref->flag & REF_ISSYMREF)
1363                                 cp = copy_advance(cp, ",symref");
1364                         if (ref->flag & REF_ISPACKED)
1365                                 cp = copy_advance(cp, ",packed");
1366                         if (cp == buf)
1367                                 v->s = "";
1368                         else {
1369                                 *cp = '\0';
1370                                 v->s = xstrdup(buf + 1);
1371                         }
1372                         continue;
1373                 } else if (!deref && grab_objectname(name, ref->objectname, v, atom)) {
1374                         continue;
1375                 } else if (!strcmp(name, "HEAD")) {
1376                         if (atom->u.head && !strcmp(ref->refname, atom->u.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 filter_ref_kind(struct ref_filter *filter, 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 (filter->kind == FILTER_REFS_BRANCHES ||
1711             filter->kind == FILTER_REFS_REMOTES ||
1712             filter->kind == FILTER_REFS_TAGS)
1713                 return filter->kind;
1714         else if (!strcmp(refname, "HEAD"))
1715                 return FILTER_REFS_DETACHED_HEAD;
1716
1717         for (i = 0; i < ARRAY_SIZE(ref_kind); i++) {
1718                 if (starts_with(refname, ref_kind[i].prefix))
1719                         return ref_kind[i].kind;
1720         }
1721
1722         return FILTER_REFS_OTHERS;
1723 }
1724
1725 /*
1726  * A call-back given to for_each_ref().  Filter refs and keep them for
1727  * later object processing.
1728  */
1729 static int ref_filter_handler(const char *refname, const struct object_id *oid, int flag, void *cb_data)
1730 {
1731         struct ref_filter_cbdata *ref_cbdata = cb_data;
1732         struct ref_filter *filter = ref_cbdata->filter;
1733         struct ref_array_item *ref;
1734         struct commit *commit = NULL;
1735         unsigned int kind;
1736
1737         if (flag & REF_BAD_NAME) {
1738                 warning(_("ignoring ref with broken name %s"), refname);
1739                 return 0;
1740         }
1741
1742         if (flag & REF_ISBROKEN) {
1743                 warning(_("ignoring broken ref %s"), refname);
1744                 return 0;
1745         }
1746
1747         /* Obtain the current ref kind from filter_ref_kind() and ignore unwanted refs. */
1748         kind = filter_ref_kind(filter, refname);
1749         if (!(kind & filter->kind))
1750                 return 0;
1751
1752         if (!filter_pattern_match(filter, refname))
1753                 return 0;
1754
1755         if (filter->points_at.nr && !match_points_at(&filter->points_at, oid->hash, refname))
1756                 return 0;
1757
1758         /*
1759          * A merge filter is applied on refs pointing to commits. Hence
1760          * obtain the commit using the 'oid' available and discard all
1761          * non-commits early. The actual filtering is done later.
1762          */
1763         if (filter->merge_commit || filter->with_commit || filter->verbose) {
1764                 commit = lookup_commit_reference_gently(oid->hash, 1);
1765                 if (!commit)
1766                         return 0;
1767                 /* We perform the filtering for the '--contains' option */
1768                 if (filter->with_commit &&
1769                     !commit_contains(filter, commit))
1770                         return 0;
1771         }
1772
1773         /*
1774          * We do not open the object yet; sort may only need refname
1775          * to do its job and the resulting list may yet to be pruned
1776          * by maxcount logic.
1777          */
1778         ref = new_ref_array_item(refname, oid->hash, flag);
1779         ref->commit = commit;
1780
1781         REALLOC_ARRAY(ref_cbdata->array->items, ref_cbdata->array->nr + 1);
1782         ref_cbdata->array->items[ref_cbdata->array->nr++] = ref;
1783         ref->kind = kind;
1784         return 0;
1785 }
1786
1787 /*  Free memory allocated for a ref_array_item */
1788 static void free_array_item(struct ref_array_item *item)
1789 {
1790         free((char *)item->symref);
1791         free(item);
1792 }
1793
1794 /* Free all memory allocated for ref_array */
1795 void ref_array_clear(struct ref_array *array)
1796 {
1797         int i;
1798
1799         for (i = 0; i < array->nr; i++)
1800                 free_array_item(array->items[i]);
1801         free(array->items);
1802         array->items = NULL;
1803         array->nr = array->alloc = 0;
1804 }
1805
1806 static void do_merge_filter(struct ref_filter_cbdata *ref_cbdata)
1807 {
1808         struct rev_info revs;
1809         int i, old_nr;
1810         struct ref_filter *filter = ref_cbdata->filter;
1811         struct ref_array *array = ref_cbdata->array;
1812         struct commit **to_clear = xcalloc(sizeof(struct commit *), array->nr);
1813
1814         init_revisions(&revs, NULL);
1815
1816         for (i = 0; i < array->nr; i++) {
1817                 struct ref_array_item *item = array->items[i];
1818                 add_pending_object(&revs, &item->commit->object, item->refname);
1819                 to_clear[i] = item->commit;
1820         }
1821
1822         filter->merge_commit->object.flags |= UNINTERESTING;
1823         add_pending_object(&revs, &filter->merge_commit->object, "");
1824
1825         revs.limited = 1;
1826         if (prepare_revision_walk(&revs))
1827                 die(_("revision walk setup failed"));
1828
1829         old_nr = array->nr;
1830         array->nr = 0;
1831
1832         for (i = 0; i < old_nr; i++) {
1833                 struct ref_array_item *item = array->items[i];
1834                 struct commit *commit = item->commit;
1835
1836                 int is_merged = !!(commit->object.flags & UNINTERESTING);
1837
1838                 if (is_merged == (filter->merge == REF_FILTER_MERGED_INCLUDE))
1839                         array->items[array->nr++] = array->items[i];
1840                 else
1841                         free_array_item(item);
1842         }
1843
1844         for (i = 0; i < old_nr; i++)
1845                 clear_commit_marks(to_clear[i], ALL_REV_FLAGS);
1846         clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
1847         free(to_clear);
1848 }
1849
1850 /*
1851  * API for filtering a set of refs. Based on the type of refs the user
1852  * has requested, we iterate through those refs and apply filters
1853  * as per the given ref_filter structure and finally store the
1854  * filtered refs in the ref_array structure.
1855  */
1856 int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int type)
1857 {
1858         struct ref_filter_cbdata ref_cbdata;
1859         int ret = 0;
1860         unsigned int broken = 0;
1861
1862         ref_cbdata.array = array;
1863         ref_cbdata.filter = filter;
1864
1865         if (type & FILTER_REFS_INCLUDE_BROKEN)
1866                 broken = 1;
1867         filter->kind = type & FILTER_REFS_KIND_MASK;
1868
1869         /*  Simple per-ref filtering */
1870         if (!filter->kind)
1871                 die("filter_refs: invalid type");
1872         else {
1873                 /*
1874                  * For common cases where we need only branches or remotes or tags,
1875                  * we only iterate through those refs. If a mix of refs is needed,
1876                  * we iterate over all refs and filter out required refs with the help
1877                  * of filter_ref_kind().
1878                  */
1879                 if (filter->kind == FILTER_REFS_BRANCHES)
1880                         ret = for_each_fullref_in("refs/heads/", ref_filter_handler, &ref_cbdata, broken);
1881                 else if (filter->kind == FILTER_REFS_REMOTES)
1882                         ret = for_each_fullref_in("refs/remotes/", ref_filter_handler, &ref_cbdata, broken);
1883                 else if (filter->kind == FILTER_REFS_TAGS)
1884                         ret = for_each_fullref_in("refs/tags/", ref_filter_handler, &ref_cbdata, broken);
1885                 else if (filter->kind & FILTER_REFS_ALL)
1886                         ret = for_each_fullref_in("", ref_filter_handler, &ref_cbdata, broken);
1887                 if (!ret && (filter->kind & FILTER_REFS_DETACHED_HEAD))
1888                         head_ref(ref_filter_handler, &ref_cbdata);
1889         }
1890
1891
1892         /*  Filters that need revision walking */
1893         if (filter->merge_commit)
1894                 do_merge_filter(&ref_cbdata);
1895
1896         return ret;
1897 }
1898
1899 static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, struct ref_array_item *b)
1900 {
1901         struct atom_value *va, *vb;
1902         int cmp;
1903         cmp_type cmp_type = used_atom[s->atom].type;
1904         int (*cmp_fn)(const char *, const char *);
1905
1906         get_ref_atom_value(a, s->atom, &va);
1907         get_ref_atom_value(b, s->atom, &vb);
1908         cmp_fn = s->ignore_case ? strcasecmp : strcmp;
1909         if (s->version)
1910                 cmp = versioncmp(va->s, vb->s);
1911         else if (cmp_type == FIELD_STR)
1912                 cmp = cmp_fn(va->s, vb->s);
1913         else {
1914                 if (va->ul < vb->ul)
1915                         cmp = -1;
1916                 else if (va->ul == vb->ul)
1917                         cmp = cmp_fn(a->refname, b->refname);
1918                 else
1919                         cmp = 1;
1920         }
1921
1922         return (s->reverse) ? -cmp : cmp;
1923 }
1924
1925 static struct ref_sorting *ref_sorting;
1926 static int compare_refs(const void *a_, const void *b_)
1927 {
1928         struct ref_array_item *a = *((struct ref_array_item **)a_);
1929         struct ref_array_item *b = *((struct ref_array_item **)b_);
1930         struct ref_sorting *s;
1931
1932         for (s = ref_sorting; s; s = s->next) {
1933                 int cmp = cmp_ref_sorting(s, a, b);
1934                 if (cmp)
1935                         return cmp;
1936         }
1937         return 0;
1938 }
1939
1940 void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
1941 {
1942         ref_sorting = sorting;
1943         QSORT(array->items, array->nr, compare_refs);
1944 }
1945
1946 static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
1947 {
1948         struct strbuf *s = &state->stack->output;
1949
1950         while (*cp && (!ep || cp < ep)) {
1951                 if (*cp == '%') {
1952                         if (cp[1] == '%')
1953                                 cp++;
1954                         else {
1955                                 int ch = hex2chr(cp + 1);
1956                                 if (0 <= ch) {
1957                                         strbuf_addch(s, ch);
1958                                         cp += 3;
1959                                         continue;
1960                                 }
1961                         }
1962                 }
1963                 strbuf_addch(s, *cp);
1964                 cp++;
1965         }
1966 }
1967
1968 void format_ref_array_item(struct ref_array_item *info, const char *format,
1969                            int quote_style, struct strbuf *final_buf)
1970 {
1971         const char *cp, *sp, *ep;
1972         struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
1973
1974         state.quote_style = quote_style;
1975         push_stack_element(&state.stack);
1976
1977         for (cp = format; *cp && (sp = find_next(cp)); cp = ep + 1) {
1978                 struct atom_value *atomv;
1979
1980                 ep = strchr(sp, ')');
1981                 if (cp < sp)
1982                         append_literal(cp, sp, &state);
1983                 get_ref_atom_value(info, parse_ref_filter_atom(sp + 2, ep), &atomv);
1984                 atomv->handler(atomv, &state);
1985         }
1986         if (*cp) {
1987                 sp = cp + strlen(cp);
1988                 append_literal(cp, sp, &state);
1989         }
1990         if (need_color_reset_at_eol) {
1991                 struct atom_value resetv;
1992                 char color[COLOR_MAXLEN] = "";
1993
1994                 if (color_parse("reset", color) < 0)
1995                         die("BUG: couldn't parse 'reset' as a color");
1996                 resetv.s = color;
1997                 append_atom(&resetv, &state);
1998         }
1999         if (state.stack->prev)
2000                 die(_("format: %%(end) atom missing"));
2001         strbuf_addbuf(final_buf, &state.stack->output);
2002         pop_stack_element(&state.stack);
2003 }
2004
2005 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
2006 {
2007         struct strbuf final_buf = STRBUF_INIT;
2008
2009         format_ref_array_item(info, format, quote_style, &final_buf);
2010         fwrite(final_buf.buf, 1, final_buf.len, stdout);
2011         strbuf_release(&final_buf);
2012         putchar('\n');
2013 }
2014
2015 /*  If no sorting option is given, use refname to sort as default */
2016 struct ref_sorting *ref_default_sorting(void)
2017 {
2018         static const char cstr_name[] = "refname";
2019
2020         struct ref_sorting *sorting = xcalloc(1, sizeof(*sorting));
2021
2022         sorting->next = NULL;
2023         sorting->atom = parse_ref_filter_atom(cstr_name, cstr_name + strlen(cstr_name));
2024         return sorting;
2025 }
2026
2027 int parse_opt_ref_sorting(const struct option *opt, const char *arg, int unset)
2028 {
2029         struct ref_sorting **sorting_tail = opt->value;
2030         struct ref_sorting *s;
2031         int len;
2032
2033         if (!arg) /* should --no-sort void the list ? */
2034                 return -1;
2035
2036         s = xcalloc(1, sizeof(*s));
2037         s->next = *sorting_tail;
2038         *sorting_tail = s;
2039
2040         if (*arg == '-') {
2041                 s->reverse = 1;
2042                 arg++;
2043         }
2044         if (skip_prefix(arg, "version:", &arg) ||
2045             skip_prefix(arg, "v:", &arg))
2046                 s->version = 1;
2047         len = strlen(arg);
2048         s->atom = parse_ref_filter_atom(arg, arg+len);
2049         return 0;
2050 }
2051
2052 int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset)
2053 {
2054         struct ref_filter *rf = opt->value;
2055         unsigned char sha1[20];
2056
2057         rf->merge = starts_with(opt->long_name, "no")
2058                 ? REF_FILTER_MERGED_OMIT
2059                 : REF_FILTER_MERGED_INCLUDE;
2060
2061         if (get_sha1(arg, sha1))
2062                 die(_("malformed object name %s"), arg);
2063
2064         rf->merge_commit = lookup_commit_reference_gently(sha1, 0);
2065         if (!rf->merge_commit)
2066                 return opterror(opt, "must point to a commit", 0);
2067
2068         return 0;
2069 }