merge-tool documentation: describe custom command usage

diff --git a/builtin-describe.c b/builtin-describe.c
index 05e309f5ad15f9a6f85df34322bb59152b4e37be..7a5ab012b1fabe3f67cd2d9bc776794e34431d80 100644 (file)
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -17,12 +17,15 @@ static const char * const describe_usage[] = {
 static int debug;      /* Display lots of verbose info */
 static int all;        /* Default to annotated tags only */
 static int tags;       /* But allow any tags if --tags is specified */
+static int longformat;
 static int abbrev = DEFAULT_ABBREV;
 static int max_candidates = 10;
 const char *pattern = NULL;
 
 struct commit_name {
+       struct tag *tag;
        int prio; /* annotated tag = 2, tag = 1, head = 0 */
+       unsigned char sha1[20];
        char path[FLEX_ARRAY]; /* more */
 };
 static const char *prio_names[] = {
@@ -31,14 +34,17 @@ static const char *prio_names[] = {
 
 static void add_to_known_names(const char *path,
                               struct commit *commit,
-                              int prio)
+                              int prio,
+                              const unsigned char *sha1)
 {
        struct commit_name *e = commit->util;
        if (!e || e->prio < prio) {
                size_t len = strlen(path)+1;
                free(e);
                e = xmalloc(sizeof(struct commit_name) + len);
+               e->tag = NULL;
                e->prio = prio;
+               hashcpy(e->sha1, sha1);
                memcpy(e->path, path, len);
                commit->util = e;
        }
@@ -89,7 +95,7 @@ static int get_name(const char *path, const unsigned char *sha1, int flag, void
                if (!tags && prio < 2)
                        return 0;
        }
-       add_to_known_names(all ? path + 5 : path + 10, commit, prio);
+       add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
        return 0;
 }
 
@@ -146,6 +152,27 @@ static unsigned long finish_depth_computation(
        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) || !n->tag->tag)
+                       die("annotated tag %s not available", n->path);
+               if (strcmp(n->tag->tag, n->path))
+                       warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
+       }
+
+       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];
@@ -170,7 +197,13 @@ static void describe(const char *arg, int last_one)
 
        n = cmit->util;
        if (n) {
-               printf("%s\n", n->path);
+               /*
+                * Exact match to an existing ref.
+                */
+               display_name(n);
+               if (longformat)
+                       show_suffix(0, n->tag->tagged->sha1);
+               printf("\n");
                return;
        }
 
@@ -252,12 +285,11 @@ static void describe(const char *arg, int last_one)
                                sha1_to_hex(gave_up_on->object.sha1));
                }
        }
-       if (abbrev == 0)
-               printf("%s\n", all_matches[0].name->path );
-       else
-               printf("%s-%d-g%s\n", all_matches[0].name->path,
-                      all_matches[0].depth,
-                      find_unique_abbrev(cmit->object.sha1, abbrev));
+
+       display_name(all_matches[0].name);
+       if (abbrev)
+               show_suffix(all_matches[0].depth, cmit->object.sha1);
+       printf("\n");
 
        if (!last_one)
                clear_commit_marks(cmit, -1);
@@ -271,6 +303,7 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
                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),
@@ -289,6 +322,9 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 
        save_commit_buffer = 0;
 
+       if (longformat && abbrev == 0)
+               die("--long is incompatible with --abbrev=0");
+
        if (contains) {
                const char **args = xmalloc((6 + argc) * sizeof(char*));
                int i = 0;