Merge branch 'sp/maint-describe-tiebreak-with-tagger-date'

* sp/maint-describe-tiebreak-with-tagger-date:
  describe: Break annotated tag ties by tagger date
  tag.c: Parse tagger date (if present)
  tag.c: Refactor parse_tag_buffer to be saner to program
  tag.h: Remove unused signature field
  tag.c: Correct indentation

diff --cc builtin/describe.c
index 71be2a9364748668996696f6c74057dba43315b5,0000000000000000000000000000000000000000..43caff2ffe185df6ab224b93b4fd9ce3d82de2d0
mode 100644,000000..100644
--- 1/builtin/describe.c
--- /dev/null
+++ b/builtin/describe.c
@@@ -1,396 -1,0 +1,437 @@@
-       int prio; /* annotated tag = 2, tag = 1, head = 0 */
 +#include "cache.h"
 +#include "commit.h"
 +#include "tag.h"
 +#include "refs.h"
 +#include "builtin.h"
 +#include "exec_cmd.h"
 +#include "parse-options.h"
 +#include "diff.h"
 +
 +#define SEEN          (1u<<0)
 +#define MAX_TAGS      (FLAG_BITS - 1)
 +
 +static const char * const describe_usage[] = {
 +      "git describe [options] <committish>*",
 +      "git describe [options] --dirty",
 +      NULL
 +};
 +
 +static int debug;     /* Display lots of verbose info */
 +static int all;       /* Any valid ref can be used */
 +static int tags;      /* Allow lightweight tags */
 +static int longformat;
 +static int abbrev = DEFAULT_ABBREV;
 +static int max_candidates = 10;
 +static int found_names;
 +static const char *pattern;
 +static int always;
 +static const char *dirty;
 +
 +/* diff-index command arguments to check if working tree is dirty. */
 +static const char *diff_index_args[] = {
 +      "diff-index", "--quiet", "HEAD", "--", NULL
 +};
 +
 +
 +struct commit_name {
 +      struct tag *tag;
-       if (!e || e->prio < prio) {
++      unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
++      unsigned name_checked:1;
 +      unsigned char sha1[20];
 +      char path[FLEX_ARRAY]; /* more */
 +};
 +static const char *prio_names[] = {
 +      "head", "lightweight", "annotated",
 +};
 +
++static int replace_name(struct commit_name *e,
++                             int prio,
++                             const unsigned char *sha1,
++                             struct tag **tag)
++{
++      if (!e || e->prio < prio)
++              return 1;
++
++      if (e->prio == 2 && prio == 2) {
++              /* Multiple annotated tags point to the same commit.
++               * Select one to keep based upon their tagger date.
++               */
++              struct tag *t;
++
++              if (!e->tag) {
++                      t = lookup_tag(e->sha1);
++                      if (!t || parse_tag(t))
++                              return 1;
++                      e->tag = t;
++              }
++
++              t = lookup_tag(sha1);
++              if (!t || parse_tag(t))
++                      return 0;
++              *tag = t;
++
++              if (e->tag->date < t->date)
++                      return 1;
++      }
++
++      return 0;
++}
++
 +static void add_to_known_names(const char *path,
 +                             struct commit *commit,
 +                             int prio,
 +                             const unsigned char *sha1)
 +{
 +      struct commit_name *e = commit->util;
-               e->tag = NULL;
++      struct tag *tag = NULL;
++      if (replace_name(e, prio, sha1, &tag)) {
 +              size_t len = strlen(path)+1;
 +              free(e);
 +              e = xmalloc(sizeof(struct commit_name) + len);
-               if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
++              e->tag = tag;
 +              e->prio = prio;
++              e->name_checked = 0;
 +              hashcpy(e->sha1, sha1);
 +              memcpy(e->path, path, len);
 +              commit->util = e;
 +      }
 +      found_names = 1;
 +}
 +
 +static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 +{
 +      int might_be_tag = !prefixcmp(path, "refs/tags/");
 +      struct commit *commit;
 +      struct object *object;
 +      unsigned char peeled[20];
 +      int is_tag, prio;
 +
 +      if (!all && !might_be_tag)
 +              return 0;
 +
 +      if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
 +              commit = lookup_commit_reference_gently(peeled, 1);
 +              if (!commit)
 +                      return 0;
 +              is_tag = !!hashcmp(sha1, commit->object.sha1);
 +      } else {
 +              commit = lookup_commit_reference_gently(sha1, 1);
 +              object = parse_object(sha1);
 +              if (!commit || !object)
 +                      return 0;
 +              is_tag = object->type == OBJ_TAG;
 +      }
 +
 +      /* If --all, then any refs are used.
 +       * If --tags, then any tags are used.
 +       * Otherwise only annotated tags are used.
 +       */
 +      if (might_be_tag) {
 +              if (is_tag)
 +                      prio = 2;
 +              else
 +                      prio = 1;
 +
 +              if (pattern && fnmatch(pattern, path + 10, 0))
 +                      prio = 0;
 +      }
 +      else
 +              prio = 0;
 +
 +      if (!all) {
 +              if (!prio)
 +                      return 0;
 +      }
 +      add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 +      return 0;
 +}
 +
 +struct possible_tag {
 +      struct commit_name *name;
 +      int depth;
 +      int found_order;
 +      unsigned flag_within;
 +};
 +
 +static int compare_pt(const void *a_, const void *b_)
 +{
 +      struct possible_tag *a = (struct possible_tag *)a_;
 +      struct possible_tag *b = (struct possible_tag *)b_;
 +      if (a->depth != b->depth)
 +              return a->depth - b->depth;
 +      if (a->found_order != b->found_order)
 +              return a->found_order - b->found_order;
 +      return 0;
 +}
 +
 +static unsigned long finish_depth_computation(
 +      struct commit_list **list,
 +      struct possible_tag *best)
 +{
 +      unsigned long seen_commits = 0;
 +      while (*list) {
 +              struct commit *c = pop_commit(list);
 +              struct commit_list *parents = c->parents;
 +              seen_commits++;
 +              if (c->object.flags & best->flag_within) {
 +                      struct commit_list *a = *list;
 +                      while (a) {
 +                              struct commit *i = a->item;
 +                              if (!(i->object.flags & best->flag_within))
 +                                      break;
 +                              a = a->next;
 +                      }
 +                      if (!a)
 +                              break;
 +              } else
 +                      best->depth++;
 +              while (parents) {
 +                      struct commit *p = parents->item;
 +                      parse_commit(p);
 +                      if (!(p->object.flags & SEEN))
 +                              insert_by_date(p, list);
 +                      p->object.flags |= c->object.flags;
 +                      parents = parents->next;
 +              }
 +      }
 +      return seen_commits;
 +}
 +
 +static void display_name(struct commit_name *n)
 +{
 +      if (n->prio == 2 && !n->tag) {
 +              n->tag = lookup_tag(n->sha1);
++              if (!n->tag || parse_tag(n->tag))
 +                      die("annotated tag %s not available", n->path);
++      }
++      if (n->tag && !n->name_checked) {
++              if (!n->tag->tag)
++                      die("annotated tag %s has no embedded name", n->path);
 +              if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 +                      warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
++              n->name_checked = 1;
 +      }
 +
 +      if (n->tag)
 +              printf("%s", n->tag->tag);
 +      else
 +              printf("%s", n->path);
 +}
 +
 +static void show_suffix(int depth, const unsigned char *sha1)
 +{
 +      printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 +}
 +
 +static void describe(const char *arg, int last_one)
 +{
 +      unsigned char sha1[20];
 +      struct commit *cmit, *gave_up_on = NULL;
 +      struct commit_list *list;
 +      struct commit_name *n;
 +      struct possible_tag all_matches[MAX_TAGS];
 +      unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 +      unsigned long seen_commits = 0;
 +      unsigned int unannotated_cnt = 0;
 +
 +      if (get_sha1(arg, sha1))
 +              die("Not a valid object name %s", arg);
 +      cmit = lookup_commit_reference(sha1);
 +      if (!cmit)
 +              die("%s is not a valid '%s' object", arg, commit_type);
 +
 +      n = cmit->util;
 +      if (n && (tags || all || n->prio == 2)) {
 +              /*
 +               * Exact match to an existing ref.
 +               */
 +              display_name(n);
 +              if (longformat)
 +                      show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 +              if (dirty)
 +                      printf("%s", dirty);
 +              printf("\n");
 +              return;
 +      }
 +
 +      if (!max_candidates)
 +              die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 +      if (debug)
 +              fprintf(stderr, "searching to describe %s\n", arg);
 +
 +      list = NULL;
 +      cmit->object.flags = SEEN;
 +      commit_list_insert(cmit, &list);
 +      while (list) {
 +              struct commit *c = pop_commit(&list);
 +              struct commit_list *parents = c->parents;
 +              seen_commits++;
 +              n = c->util;
 +              if (n) {
 +                      if (!tags && !all && n->prio < 2) {
 +                              unannotated_cnt++;
 +                      } else if (match_cnt < max_candidates) {
 +                              struct possible_tag *t = &all_matches[match_cnt++];
 +                              t->name = n;
 +                              t->depth = seen_commits - 1;
 +                              t->flag_within = 1u << match_cnt;
 +                              t->found_order = match_cnt;
 +                              c->object.flags |= t->flag_within;
 +                              if (n->prio == 2)
 +                                      annotated_cnt++;
 +                      }
 +                      else {
 +                              gave_up_on = c;
 +                              break;
 +                      }
 +              }
 +              for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 +                      struct possible_tag *t = &all_matches[cur_match];
 +                      if (!(c->object.flags & t->flag_within))
 +                              t->depth++;
 +              }
 +              if (annotated_cnt && !list) {
 +                      if (debug)
 +                              fprintf(stderr, "finished search at %s\n",
 +                                      sha1_to_hex(c->object.sha1));
 +                      break;
 +              }
 +              while (parents) {
 +                      struct commit *p = parents->item;
 +                      parse_commit(p);
 +                      if (!(p->object.flags & SEEN))
 +                              insert_by_date(p, &list);
 +                      p->object.flags |= c->object.flags;
 +                      parents = parents->next;
 +              }
 +      }
 +
 +      if (!match_cnt) {
 +              const unsigned char *sha1 = cmit->object.sha1;
 +              if (always) {
 +                      printf("%s", find_unique_abbrev(sha1, abbrev));
 +                      if (dirty)
 +                              printf("%s", dirty);
 +                      printf("\n");
 +                      return;
 +              }
 +              if (unannotated_cnt)
 +                      die("No annotated tags can describe '%s'.\n"
 +                          "However, there were unannotated tags: try --tags.",
 +                          sha1_to_hex(sha1));
 +              else
 +                      die("No tags can describe '%s'.\n"
 +                          "Try --always, or create some tags.",
 +                          sha1_to_hex(sha1));
 +      }
 +
 +      qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 +
 +      if (gave_up_on) {
 +              insert_by_date(gave_up_on, &list);
 +              seen_commits--;
 +      }
 +      seen_commits += finish_depth_computation(&list, &all_matches[0]);
 +      free_commit_list(list);
 +
 +      if (debug) {
 +              for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 +                      struct possible_tag *t = &all_matches[cur_match];
 +                      fprintf(stderr, " %-11s %8d %s\n",
 +                              prio_names[t->name->prio],
 +                              t->depth, t->name->path);
 +              }
 +              fprintf(stderr, "traversed %lu commits\n", seen_commits);
 +              if (gave_up_on) {
 +                      fprintf(stderr,
 +                              "more than %i tags found; listed %i most recent\n"
 +                              "gave up search at %s\n",
 +                              max_candidates, max_candidates,
 +                              sha1_to_hex(gave_up_on->object.sha1));
 +              }
 +      }
 +
 +      display_name(all_matches[0].name);
 +      if (abbrev)
 +              show_suffix(all_matches[0].depth, cmit->object.sha1);
 +      if (dirty)
 +              printf("%s", dirty);
 +      printf("\n");
 +
 +      if (!last_one)
 +              clear_commit_marks(cmit, -1);
 +}
 +
 +int cmd_describe(int argc, const char **argv, const char *prefix)
 +{
 +      int contains = 0;
 +      struct option options[] = {
 +              OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 +              OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 +              OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 +              OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 +              OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 +              OPT__ABBREV(&abbrev),
 +              OPT_SET_INT(0, "exact-match", &max_candidates,
 +                          "only output exact matches", 0),
 +              OPT_INTEGER(0, "candidates", &max_candidates,
 +                          "consider <n> most recent tags (default: 10)"),
 +              OPT_STRING(0, "match",       &pattern, "pattern",
 +                         "only consider tags matching <pattern>"),
 +              OPT_BOOLEAN(0, "always",     &always,
 +                         "show abbreviated commit object as fallback"),
 +              {OPTION_STRING, 0, "dirty",  &dirty, "mark",
 +                         "append <mark> on dirty working tree (default: \"-dirty\")",
 +               PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 +              OPT_END(),
 +      };
 +
 +      argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 +      if (max_candidates < 0)
 +              max_candidates = 0;
 +      else if (max_candidates > MAX_TAGS)
 +              max_candidates = MAX_TAGS;
 +
 +      save_commit_buffer = 0;
 +
 +      if (longformat && abbrev == 0)
 +              die("--long is incompatible with --abbrev=0");
 +
 +      if (contains) {
 +              const char **args = xmalloc((7 + argc) * sizeof(char *));
 +              int i = 0;
 +              args[i++] = "name-rev";
 +              args[i++] = "--name-only";
 +              args[i++] = "--no-undefined";
 +              if (always)
 +                      args[i++] = "--always";
 +              if (!all) {
 +                      args[i++] = "--tags";
 +                      if (pattern) {
 +                              char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 +                              sprintf(s, "--refs=refs/tags/%s", pattern);
 +                              args[i++] = s;
 +                      }
 +              }
 +              memcpy(args + i, argv, argc * sizeof(char *));
 +              args[i + argc] = NULL;
 +              return cmd_name_rev(i + argc, args, prefix);
 +      }
 +
 +      for_each_ref(get_name, NULL);
 +      if (!found_names && !always)
 +              die("No names found, cannot describe anything.");
 +
 +      if (argc == 0) {
 +              if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
 +                      dirty = NULL;
 +              describe("HEAD", 1);
 +      } else if (dirty) {
 +              die("--dirty is incompatible with committishes");
 +      } else {
 +              while (argc-- > 0) {
 +                      describe(*argv++, argc == 0);
 +              }
 +      }
 +      return 0;
 +}