Code

Move 'builtin-*' into a 'builtin/' subdirectory
[git.git] / builtin / show-branch.c
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
new file mode 100644 (file)
index 0000000..35a709e
--- /dev/null
@@ -0,0 +1,967 @@
+#include "cache.h"
+#include "commit.h"
+#include "refs.h"
+#include "builtin.h"
+#include "color.h"
+#include "parse-options.h"
+
+static const char* show_branch_usage[] = {
+    "git show-branch [-a|--all] [-r|--remotes] [--topo-order | --date-order] [--current] [--color | --no-color] [--sparse] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [--topics] [<rev> | <glob>]...",
+    "git show-branch (-g|--reflog)[=<n>[,<base>]] [--list] [<ref>]",
+    NULL
+};
+
+static int showbranch_use_color = -1;
+static char column_colors[][COLOR_MAXLEN] = {
+       GIT_COLOR_RED,
+       GIT_COLOR_GREEN,
+       GIT_COLOR_YELLOW,
+       GIT_COLOR_BLUE,
+       GIT_COLOR_MAGENTA,
+       GIT_COLOR_CYAN,
+};
+
+#define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
+
+static int default_num;
+static int default_alloc;
+static const char **default_arg;
+
+#define UNINTERESTING  01
+
+#define REV_SHIFT       2
+#define MAX_REVS       (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
+
+#define DEFAULT_REFLOG 4
+
+static const char *get_color_code(int idx)
+{
+       if (showbranch_use_color)
+               return column_colors[idx];
+       return "";
+}
+
+static const char *get_color_reset_code(void)
+{
+       if (showbranch_use_color)
+               return GIT_COLOR_RESET;
+       return "";
+}
+
+static struct commit *interesting(struct commit_list *list)
+{
+       while (list) {
+               struct commit *commit = list->item;
+               list = list->next;
+               if (commit->object.flags & UNINTERESTING)
+                       continue;
+               return commit;
+       }
+       return NULL;
+}
+
+static struct commit *pop_one_commit(struct commit_list **list_p)
+{
+       struct commit *commit;
+       struct commit_list *list;
+       list = *list_p;
+       commit = list->item;
+       *list_p = list->next;
+       free(list);
+       return commit;
+}
+
+struct commit_name {
+       const char *head_name; /* which head's ancestor? */
+       int generation; /* how many parents away from head_name */
+};
+
+/* Name the commit as nth generation ancestor of head_name;
+ * we count only the first-parent relationship for naming purposes.
+ */
+static void name_commit(struct commit *commit, const char *head_name, int nth)
+{
+       struct commit_name *name;
+       if (!commit->util)
+               commit->util = xmalloc(sizeof(struct commit_name));
+       name = commit->util;
+       name->head_name = head_name;
+       name->generation = nth;
+}
+
+/* Parent is the first parent of the commit.  We may name it
+ * as (n+1)th generation ancestor of the same head_name as
+ * commit is nth generation ancestor of, if that generation
+ * number is better than the name it already has.
+ */
+static void name_parent(struct commit *commit, struct commit *parent)
+{
+       struct commit_name *commit_name = commit->util;
+       struct commit_name *parent_name = parent->util;
+       if (!commit_name)
+               return;
+       if (!parent_name ||
+           commit_name->generation + 1 < parent_name->generation)
+               name_commit(parent, commit_name->head_name,
+                           commit_name->generation + 1);
+}
+
+static int name_first_parent_chain(struct commit *c)
+{
+       int i = 0;
+       while (c) {
+               struct commit *p;
+               if (!c->util)
+                       break;
+               if (!c->parents)
+                       break;
+               p = c->parents->item;
+               if (!p->util) {
+                       name_parent(c, p);
+                       i++;
+               }
+               else
+                       break;
+               c = p;
+       }
+       return i;
+}
+
+static void name_commits(struct commit_list *list,
+                        struct commit **rev,
+                        char **ref_name,
+                        int num_rev)
+{
+       struct commit_list *cl;
+       struct commit *c;
+       int i;
+
+       /* First give names to the given heads */
+       for (cl = list; cl; cl = cl->next) {
+               c = cl->item;
+               if (c->util)
+                       continue;
+               for (i = 0; i < num_rev; i++) {
+                       if (rev[i] == c) {
+                               name_commit(c, ref_name[i], 0);
+                               break;
+                       }
+               }
+       }
+
+       /* Then commits on the first parent ancestry chain */
+       do {
+               i = 0;
+               for (cl = list; cl; cl = cl->next) {
+                       i += name_first_parent_chain(cl->item);
+               }
+       } while (i);
+
+       /* Finally, any unnamed commits */
+       do {
+               i = 0;
+               for (cl = list; cl; cl = cl->next) {
+                       struct commit_list *parents;
+                       struct commit_name *n;
+                       int nth;
+                       c = cl->item;
+                       if (!c->util)
+                               continue;
+                       n = c->util;
+                       parents = c->parents;
+                       nth = 0;
+                       while (parents) {
+                               struct commit *p = parents->item;
+                               char newname[1000], *en;
+                               parents = parents->next;
+                               nth++;
+                               if (p->util)
+                                       continue;
+                               en = newname;
+                               switch (n->generation) {
+                               case 0:
+                                       en += sprintf(en, "%s", n->head_name);
+                                       break;
+                               case 1:
+                                       en += sprintf(en, "%s^", n->head_name);
+                                       break;
+                               default:
+                                       en += sprintf(en, "%s~%d",
+                                               n->head_name, n->generation);
+                                       break;
+                               }
+                               if (nth == 1)
+                                       en += sprintf(en, "^");
+                               else
+                                       en += sprintf(en, "^%d", nth);
+                               name_commit(p, xstrdup(newname), 0);
+                               i++;
+                               name_first_parent_chain(p);
+                       }
+               }
+       } while (i);
+}
+
+static int mark_seen(struct commit *commit, struct commit_list **seen_p)
+{
+       if (!commit->object.flags) {
+               commit_list_insert(commit, seen_p);
+               return 1;
+       }
+       return 0;
+}
+
+static void join_revs(struct commit_list **list_p,
+                     struct commit_list **seen_p,
+                     int num_rev, int extra)
+{
+       int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
+       int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
+
+       while (*list_p) {
+               struct commit_list *parents;
+               int still_interesting = !!interesting(*list_p);
+               struct commit *commit = pop_one_commit(list_p);
+               int flags = commit->object.flags & all_mask;
+
+               if (!still_interesting && extra <= 0)
+                       break;
+
+               mark_seen(commit, seen_p);
+               if ((flags & all_revs) == all_revs)
+                       flags |= UNINTERESTING;
+               parents = commit->parents;
+
+               while (parents) {
+                       struct commit *p = parents->item;
+                       int this_flag = p->object.flags;
+                       parents = parents->next;
+                       if ((this_flag & flags) == flags)
+                               continue;
+                       if (!p->object.parsed)
+                               parse_commit(p);
+                       if (mark_seen(p, seen_p) && !still_interesting)
+                               extra--;
+                       p->object.flags |= flags;
+                       insert_by_date(p, list_p);
+               }
+       }
+
+       /*
+        * Postprocess to complete well-poisoning.
+        *
+        * At this point we have all the commits we have seen in
+        * seen_p list.  Mark anything that can be reached from
+        * uninteresting commits not interesting.
+        */
+       for (;;) {
+               int changed = 0;
+               struct commit_list *s;
+               for (s = *seen_p; s; s = s->next) {
+                       struct commit *c = s->item;
+                       struct commit_list *parents;
+
+                       if (((c->object.flags & all_revs) != all_revs) &&
+                           !(c->object.flags & UNINTERESTING))
+                               continue;
+
+                       /* The current commit is either a merge base or
+                        * already uninteresting one.  Mark its parents
+                        * as uninteresting commits _only_ if they are
+                        * already parsed.  No reason to find new ones
+                        * here.
+                        */
+                       parents = c->parents;
+                       while (parents) {
+                               struct commit *p = parents->item;
+                               parents = parents->next;
+                               if (!(p->object.flags & UNINTERESTING)) {
+                                       p->object.flags |= UNINTERESTING;
+                                       changed = 1;
+                               }
+                       }
+               }
+               if (!changed)
+                       break;
+       }
+}
+
+static void show_one_commit(struct commit *commit, int no_name)
+{
+       struct strbuf pretty = STRBUF_INIT;
+       const char *pretty_str = "(unavailable)";
+       struct commit_name *name = commit->util;
+
+       if (commit->object.parsed) {
+               struct pretty_print_context ctx = {0};
+               pretty_print_commit(CMIT_FMT_ONELINE, commit, &pretty, &ctx);
+               pretty_str = pretty.buf;
+       }
+       if (!prefixcmp(pretty_str, "[PATCH] "))
+               pretty_str += 8;
+
+       if (!no_name) {
+               if (name && name->head_name) {
+                       printf("[%s", name->head_name);
+                       if (name->generation) {
+                               if (name->generation == 1)
+                                       printf("^");
+                               else
+                                       printf("~%d", name->generation);
+                       }
+                       printf("] ");
+               }
+               else
+                       printf("[%s] ",
+                              find_unique_abbrev(commit->object.sha1, 7));
+       }
+       puts(pretty_str);
+       strbuf_release(&pretty);
+}
+
+static char *ref_name[MAX_REVS + 1];
+static int ref_name_cnt;
+
+static const char *find_digit_prefix(const char *s, int *v)
+{
+       const char *p;
+       int ver;
+       char ch;
+
+       for (p = s, ver = 0;
+            '0' <= (ch = *p) && ch <= '9';
+            p++)
+               ver = ver * 10 + ch - '0';
+       *v = ver;
+       return p;
+}
+
+
+static int version_cmp(const char *a, const char *b)
+{
+       while (1) {
+               int va, vb;
+
+               a = find_digit_prefix(a, &va);
+               b = find_digit_prefix(b, &vb);
+               if (va != vb)
+                       return va - vb;
+
+               while (1) {
+                       int ca = *a;
+                       int cb = *b;
+                       if ('0' <= ca && ca <= '9')
+                               ca = 0;
+                       if ('0' <= cb && cb <= '9')
+                               cb = 0;
+                       if (ca != cb)
+                               return ca - cb;
+                       if (!ca)
+                               break;
+                       a++;
+                       b++;
+               }
+               if (!*a && !*b)
+                       return 0;
+       }
+}
+
+static int compare_ref_name(const void *a_, const void *b_)
+{
+       const char * const*a = a_, * const*b = b_;
+       return version_cmp(*a, *b);
+}
+
+static void sort_ref_range(int bottom, int top)
+{
+       qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
+             compare_ref_name);
+}
+
+static int append_ref(const char *refname, const unsigned char *sha1,
+                     int allow_dups)
+{
+       struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+       int i;
+
+       if (!commit)
+               return 0;
+
+       if (!allow_dups) {
+               /* Avoid adding the same thing twice */
+               for (i = 0; i < ref_name_cnt; i++)
+                       if (!strcmp(refname, ref_name[i]))
+                               return 0;
+       }
+       if (MAX_REVS <= ref_name_cnt) {
+               warning("ignoring %s; cannot handle more than %d refs",
+                       refname, MAX_REVS);
+               return 0;
+       }
+       ref_name[ref_name_cnt++] = xstrdup(refname);
+       ref_name[ref_name_cnt] = NULL;
+       return 0;
+}
+
+static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+       unsigned char tmp[20];
+       int ofs = 11;
+       if (prefixcmp(refname, "refs/heads/"))
+               return 0;
+       /* If both heads/foo and tags/foo exists, get_sha1 would
+        * get confused.
+        */
+       if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
+               ofs = 5;
+       return append_ref(refname + ofs, sha1, 0);
+}
+
+static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+       unsigned char tmp[20];
+       int ofs = 13;
+       if (prefixcmp(refname, "refs/remotes/"))
+               return 0;
+       /* If both heads/foo and tags/foo exists, get_sha1 would
+        * get confused.
+        */
+       if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
+               ofs = 5;
+       return append_ref(refname + ofs, sha1, 0);
+}
+
+static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+       if (prefixcmp(refname, "refs/tags/"))
+               return 0;
+       return append_ref(refname + 5, sha1, 0);
+}
+
+static const char *match_ref_pattern = NULL;
+static int match_ref_slash = 0;
+static int count_slash(const char *s)
+{
+       int cnt = 0;
+       while (*s)
+               if (*s++ == '/')
+                       cnt++;
+       return cnt;
+}
+
+static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+       /* we want to allow pattern hold/<asterisk> to show all
+        * branches under refs/heads/hold/, and v0.99.9? to show
+        * refs/tags/v0.99.9a and friends.
+        */
+       const char *tail;
+       int slash = count_slash(refname);
+       for (tail = refname; *tail && match_ref_slash < slash; )
+               if (*tail++ == '/')
+                       slash--;
+       if (!*tail)
+               return 0;
+       if (fnmatch(match_ref_pattern, tail, 0))
+               return 0;
+       if (!prefixcmp(refname, "refs/heads/"))
+               return append_head_ref(refname, sha1, flag, cb_data);
+       if (!prefixcmp(refname, "refs/tags/"))
+               return append_tag_ref(refname, sha1, flag, cb_data);
+       return append_ref(refname, sha1, 0);
+}
+
+static void snarf_refs(int head, int remotes)
+{
+       if (head) {
+               int orig_cnt = ref_name_cnt;
+               for_each_ref(append_head_ref, NULL);
+               sort_ref_range(orig_cnt, ref_name_cnt);
+       }
+       if (remotes) {
+               int orig_cnt = ref_name_cnt;
+               for_each_ref(append_remote_ref, NULL);
+               sort_ref_range(orig_cnt, ref_name_cnt);
+       }
+}
+
+static int rev_is_head(char *head, int headlen, char *name,
+                      unsigned char *head_sha1, unsigned char *sha1)
+{
+       if ((!head[0]) ||
+           (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
+               return 0;
+       if (!prefixcmp(head, "refs/heads/"))
+               head += 11;
+       if (!prefixcmp(name, "refs/heads/"))
+               name += 11;
+       else if (!prefixcmp(name, "heads/"))
+               name += 6;
+       return !strcmp(head, name);
+}
+
+static int show_merge_base(struct commit_list *seen, int num_rev)
+{
+       int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
+       int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
+       int exit_status = 1;
+
+       while (seen) {
+               struct commit *commit = pop_one_commit(&seen);
+               int flags = commit->object.flags & all_mask;
+               if (!(flags & UNINTERESTING) &&
+                   ((flags & all_revs) == all_revs)) {
+                       puts(sha1_to_hex(commit->object.sha1));
+                       exit_status = 0;
+                       commit->object.flags |= UNINTERESTING;
+               }
+       }
+       return exit_status;
+}
+
+static int show_independent(struct commit **rev,
+                           int num_rev,
+                           char **ref_name,
+                           unsigned int *rev_mask)
+{
+       int i;
+
+       for (i = 0; i < num_rev; i++) {
+               struct commit *commit = rev[i];
+               unsigned int flag = rev_mask[i];
+
+               if (commit->object.flags == flag)
+                       puts(sha1_to_hex(commit->object.sha1));
+               commit->object.flags |= UNINTERESTING;
+       }
+       return 0;
+}
+
+static void append_one_rev(const char *av)
+{
+       unsigned char revkey[20];
+       if (!get_sha1(av, revkey)) {
+               append_ref(av, revkey, 0);
+               return;
+       }
+       if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
+               /* glob style match */
+               int saved_matches = ref_name_cnt;
+               match_ref_pattern = av;
+               match_ref_slash = count_slash(av);
+               for_each_ref(append_matching_ref, NULL);
+               if (saved_matches == ref_name_cnt &&
+                   ref_name_cnt < MAX_REVS)
+                       error("no matching refs with %s", av);
+               if (saved_matches + 1 < ref_name_cnt)
+                       sort_ref_range(saved_matches, ref_name_cnt);
+               return;
+       }
+       die("bad sha1 reference %s", av);
+}
+
+static int git_show_branch_config(const char *var, const char *value, void *cb)
+{
+       if (!strcmp(var, "showbranch.default")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               /*
+                * default_arg is now passed to parse_options(), so we need to
+                * mimic the real argv a bit better.
+                */
+               if (!default_num) {
+                       default_alloc = 20;
+                       default_arg = xcalloc(default_alloc, sizeof(*default_arg));
+                       default_arg[default_num++] = "show-branch";
+               } else if (default_alloc <= default_num + 1) {
+                       default_alloc = default_alloc * 3 / 2 + 20;
+                       default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
+               }
+               default_arg[default_num++] = xstrdup(value);
+               default_arg[default_num] = NULL;
+               return 0;
+       }
+
+       if (!strcmp(var, "color.showbranch")) {
+               showbranch_use_color = git_config_colorbool(var, value, -1);
+               return 0;
+       }
+
+       return git_color_default_config(var, value, cb);
+}
+
+static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
+{
+       /* If the commit is tip of the named branches, do not
+        * omit it.
+        * Otherwise, if it is a merge that is reachable from only one
+        * tip, it is not that interesting.
+        */
+       int i, flag, count;
+       for (i = 0; i < n; i++)
+               if (rev[i] == commit)
+                       return 0;
+       flag = commit->object.flags;
+       for (i = count = 0; i < n; i++) {
+               if (flag & (1u << (i + REV_SHIFT)))
+                       count++;
+       }
+       if (count == 1)
+               return 1;
+       return 0;
+}
+
+static int reflog = 0;
+
+static int parse_reflog_param(const struct option *opt, const char *arg,
+                             int unset)
+{
+       char *ep;
+       const char **base = (const char **)opt->value;
+       if (!arg)
+               arg = "";
+       reflog = strtoul(arg, &ep, 10);
+       if (*ep == ',')
+               *base = ep + 1;
+       else if (*ep)
+               return error("unrecognized reflog param '%s'", arg);
+       else
+               *base = NULL;
+       if (reflog <= 0)
+               reflog = DEFAULT_REFLOG;
+       return 0;
+}
+
+int cmd_show_branch(int ac, const char **av, const char *prefix)
+{
+       struct commit *rev[MAX_REVS], *commit;
+       char *reflog_msg[MAX_REVS];
+       struct commit_list *list = NULL, *seen = NULL;
+       unsigned int rev_mask[MAX_REVS];
+       int num_rev, i, extra = 0;
+       int all_heads = 0, all_remotes = 0;
+       int all_mask, all_revs;
+       int lifo = 1;
+       char head[128];
+       const char *head_p;
+       int head_len;
+       unsigned char head_sha1[20];
+       int merge_base = 0;
+       int independent = 0;
+       int no_name = 0;
+       int sha1_name = 0;
+       int shown_merge_point = 0;
+       int with_current_branch = 0;
+       int head_at = -1;
+       int topics = 0;
+       int dense = 1;
+       const char *reflog_base = NULL;
+       struct option builtin_show_branch_options[] = {
+               OPT_BOOLEAN('a', "all", &all_heads,
+                           "show remote-tracking and local branches"),
+               OPT_BOOLEAN('r', "remotes", &all_remotes,
+                           "show remote-tracking branches"),
+               OPT_BOOLEAN(0, "color", &showbranch_use_color,
+                           "color '*!+-' corresponding to the branch"),
+               { OPTION_INTEGER, 0, "more", &extra, "n",
+                           "show <n> more commits after the common ancestor",
+                           PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
+               OPT_SET_INT(0, "list", &extra, "synonym to more=-1", -1),
+               OPT_BOOLEAN(0, "no-name", &no_name, "suppress naming strings"),
+               OPT_BOOLEAN(0, "current", &with_current_branch,
+                           "include the current branch"),
+               OPT_BOOLEAN(0, "sha1-name", &sha1_name,
+                           "name commits with their object names"),
+               OPT_BOOLEAN(0, "merge-base", &merge_base,
+                           "show possible merge bases"),
+               OPT_BOOLEAN(0, "independent", &independent,
+                           "show refs unreachable from any other ref"),
+               OPT_BOOLEAN(0, "topo-order", &lifo,
+                           "show commits in topological order"),
+               OPT_BOOLEAN(0, "topics", &topics,
+                           "show only commits not on the first branch"),
+               OPT_SET_INT(0, "sparse", &dense,
+                           "show merges reachable from only one tip", 0),
+               OPT_SET_INT(0, "date-order", &lifo,
+                           "show commits where no parent comes before its "
+                           "children", 0),
+               { OPTION_CALLBACK, 'g', "reflog", &reflog_base, "<n>[,<base>]",
+                           "show <n> most recent ref-log entries starting at "
+                           "base",
+                           PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
+                           parse_reflog_param },
+               OPT_END()
+       };
+
+       git_config(git_show_branch_config, NULL);
+
+       if (showbranch_use_color == -1)
+               showbranch_use_color = git_use_color_default;
+
+       /* If nothing is specified, try the default first */
+       if (ac == 1 && default_num) {
+               ac = default_num;
+               av = default_arg;
+       }
+
+       ac = parse_options(ac, av, prefix, builtin_show_branch_options,
+                          show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
+       if (all_heads)
+               all_remotes = 1;
+
+       if (extra || reflog) {
+               /* "listing" mode is incompatible with
+                * independent nor merge-base modes.
+                */
+               if (independent || merge_base)
+                       usage_with_options(show_branch_usage,
+                                          builtin_show_branch_options);
+               if (reflog && ((0 < extra) || all_heads || all_remotes))
+                       /*
+                        * Asking for --more in reflog mode does not
+                        * make sense.  --list is Ok.
+                        *
+                        * Also --all and --remotes do not make sense either.
+                        */
+                       die("--reflog is incompatible with --all, --remotes, "
+                           "--independent or --merge-base");
+       }
+
+       /* If nothing is specified, show all branches by default */
+       if (ac + all_heads + all_remotes == 0)
+               all_heads = 1;
+
+       if (reflog) {
+               unsigned char sha1[20];
+               char nth_desc[256];
+               char *ref;
+               int base = 0;
+
+               if (ac == 0) {
+                       static const char *fake_av[2];
+                       const char *refname;
+
+                       refname = resolve_ref("HEAD", sha1, 1, NULL);
+                       fake_av[0] = xstrdup(refname);
+                       fake_av[1] = NULL;
+                       av = fake_av;
+                       ac = 1;
+               }
+               if (ac != 1)
+                       die("--reflog option needs one branch name");
+
+               if (MAX_REVS < reflog)
+                       die("Only %d entries can be shown at one time.",
+                           MAX_REVS);
+               if (!dwim_ref(*av, strlen(*av), sha1, &ref))
+                       die("No such ref %s", *av);
+
+               /* Has the base been specified? */
+               if (reflog_base) {
+                       char *ep;
+                       base = strtoul(reflog_base, &ep, 10);
+                       if (*ep) {
+                               /* Ah, that is a date spec... */
+                               unsigned long at;
+                               at = approxidate(reflog_base);
+                               read_ref_at(ref, at, -1, sha1, NULL,
+                                           NULL, NULL, &base);
+                       }
+               }
+
+               for (i = 0; i < reflog; i++) {
+                       char *logmsg, *m;
+                       const char *msg;
+                       unsigned long timestamp;
+                       int tz;
+
+                       if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
+                                       &timestamp, &tz, NULL)) {
+                               reflog = i;
+                               break;
+                       }
+                       msg = strchr(logmsg, '\t');
+                       if (!msg)
+                               msg = "(none)";
+                       else
+                               msg++;
+                       m = xmalloc(strlen(msg) + 200);
+                       sprintf(m, "(%s) %s",
+                               show_date(timestamp, tz, 1),
+                               msg);
+                       reflog_msg[i] = m;
+                       free(logmsg);
+                       sprintf(nth_desc, "%s@{%d}", *av, base+i);
+                       append_ref(nth_desc, sha1, 1);
+               }
+       }
+       else if (all_heads + all_remotes)
+               snarf_refs(all_heads, all_remotes);
+       else {
+               while (0 < ac) {
+                       append_one_rev(*av);
+                       ac--; av++;
+               }
+       }
+
+       head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
+       if (head_p) {
+               head_len = strlen(head_p);
+               memcpy(head, head_p, head_len + 1);
+       }
+       else {
+               head_len = 0;
+               head[0] = 0;
+       }
+
+       if (with_current_branch && head_p) {
+               int has_head = 0;
+               for (i = 0; !has_head && i < ref_name_cnt; i++) {
+                       /* We are only interested in adding the branch
+                        * HEAD points at.
+                        */
+                       if (rev_is_head(head,
+                                       head_len,
+                                       ref_name[i],
+                                       head_sha1, NULL))
+                               has_head++;
+               }
+               if (!has_head) {
+                       int offset = !prefixcmp(head, "refs/heads/") ? 11 : 0;
+                       append_one_rev(head + offset);
+               }
+       }
+
+       if (!ref_name_cnt) {
+               fprintf(stderr, "No revs to be shown.\n");
+               exit(0);
+       }
+
+       for (num_rev = 0; ref_name[num_rev]; num_rev++) {
+               unsigned char revkey[20];
+               unsigned int flag = 1u << (num_rev + REV_SHIFT);
+
+               if (MAX_REVS <= num_rev)
+                       die("cannot handle more than %d revs.", MAX_REVS);
+               if (get_sha1(ref_name[num_rev], revkey))
+                       die("'%s' is not a valid ref.", ref_name[num_rev]);
+               commit = lookup_commit_reference(revkey);
+               if (!commit)
+                       die("cannot find commit %s (%s)",
+                           ref_name[num_rev], revkey);
+               parse_commit(commit);
+               mark_seen(commit, &seen);
+
+               /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
+                * and so on.  REV_SHIFT bits from bit 0 are used for
+                * internal bookkeeping.
+                */
+               commit->object.flags |= flag;
+               if (commit->object.flags == flag)
+                       insert_by_date(commit, &list);
+               rev[num_rev] = commit;
+       }
+       for (i = 0; i < num_rev; i++)
+               rev_mask[i] = rev[i]->object.flags;
+
+       if (0 <= extra)
+               join_revs(&list, &seen, num_rev, extra);
+
+       sort_by_date(&seen);
+
+       if (merge_base)
+               return show_merge_base(seen, num_rev);
+
+       if (independent)
+               return show_independent(rev, num_rev, ref_name, rev_mask);
+
+       /* Show list; --more=-1 means list-only */
+       if (1 < num_rev || extra < 0) {
+               for (i = 0; i < num_rev; i++) {
+                       int j;
+                       int is_head = rev_is_head(head,
+                                                 head_len,
+                                                 ref_name[i],
+                                                 head_sha1,
+                                                 rev[i]->object.sha1);
+                       if (extra < 0)
+                               printf("%c [%s] ",
+                                      is_head ? '*' : ' ', ref_name[i]);
+                       else {
+                               for (j = 0; j < i; j++)
+                                       putchar(' ');
+                               printf("%s%c%s [%s] ",
+                                      get_color_code(i % COLUMN_COLORS_MAX),
+                                      is_head ? '*' : '!',
+                                      get_color_reset_code(), ref_name[i]);
+                       }
+
+                       if (!reflog) {
+                               /* header lines never need name */
+                               show_one_commit(rev[i], 1);
+                       }
+                       else
+                               puts(reflog_msg[i]);
+
+                       if (is_head)
+                               head_at = i;
+               }
+               if (0 <= extra) {
+                       for (i = 0; i < num_rev; i++)
+                               putchar('-');
+                       putchar('\n');
+               }
+       }
+       if (extra < 0)
+               exit(0);
+
+       /* Sort topologically */
+       sort_in_topological_order(&seen, lifo);
+
+       /* Give names to commits */
+       if (!sha1_name && !no_name)
+               name_commits(seen, rev, ref_name, num_rev);
+
+       all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
+       all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
+
+       while (seen) {
+               struct commit *commit = pop_one_commit(&seen);
+               int this_flag = commit->object.flags;
+               int is_merge_point = ((this_flag & all_revs) == all_revs);
+
+               shown_merge_point |= is_merge_point;
+
+               if (1 < num_rev) {
+                       int is_merge = !!(commit->parents &&
+                                         commit->parents->next);
+                       if (topics &&
+                           !is_merge_point &&
+                           (this_flag & (1u << REV_SHIFT)))
+                               continue;
+                       if (dense && is_merge &&
+                           omit_in_dense(commit, rev, num_rev))
+                               continue;
+                       for (i = 0; i < num_rev; i++) {
+                               int mark;
+                               if (!(this_flag & (1u << (i + REV_SHIFT))))
+                                       mark = ' ';
+                               else if (is_merge)
+                                       mark = '-';
+                               else if (i == head_at)
+                                       mark = '*';
+                               else
+                                       mark = '+';
+                               printf("%s%c%s",
+                                      get_color_code(i % COLUMN_COLORS_MAX),
+                                      mark, get_color_reset_code());
+                       }
+                       putchar(' ');
+               }
+               show_one_commit(commit, no_name);
+
+               if (shown_merge_point && --extra < 0)
+                       break;
+       }
+       return 0;
+}