Merge branch 'sp/describe'

* sp/describe:
Use git-describe --exact-match in bash prompt on detached HEAD
Teach git-describe --exact-match to avoid expensive tag searches
Avoid accessing non-tag refs in git-describe unless --all is requested
Teach git-describe to use peeled ref information when scanning tags
Optimize peel_ref for the current ref of a for_each_ref callback

diff --git a/Documentation/git-describe.txt b/Documentation/git-describe.txt
index 1c3dfb40c63350651efb570ed540b69c34ccbc81..fbb40a29165a47e627358b5b9f8afb50e84958cd 100644 (file)
--- a/Documentation/git-describe.txt
+++ b/Documentation/git-describe.txt
@@ -45,6 +45,11 @@ OPTIONS
        candidates to describe the input committish consider
        up to <n> candidates.  Increasing <n> above 10 will take
        slightly longer but may produce a more accurate result.
+       An <n> of 0 will cause only exact matches to be output.
+
+--exact-match::
+       Only output exact matches (a tag directly references the
+       supplied commit).  This is a synonym for --candidates=0.
 
 --debug::
        Verbosely display information about the searching strategy

diff --git a/builtin-describe.c b/builtin-describe.c
index 3428483134156f4e1761aa47ed2e8098a294808c..05e309f5ad15f9a6f85df34322bb59152b4e37be 100644 (file)
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -46,19 +46,34 @@ static void add_to_known_names(const char *path,
 
 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
-       struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+       int might_be_tag = !prefixcmp(path, "refs/tags/");
+       struct commit *commit;
        struct object *object;
-       int prio;
+       unsigned char peeled[20];
+       int is_tag, prio;
 
-       if (!commit)
+       if (!all && !might_be_tag)
                return 0;
-       object = parse_object(sha1);
+
+       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 (!prefixcmp(path, "refs/tags/")) {
-               if (object->type == OBJ_TAG) {
+       if (might_be_tag) {
+               if (is_tag) {
                        prio = 2;
                        if (pattern && fnmatch(pattern, path + 10, 0))
                                prio = 0;
@@ -159,6 +174,8 @@ static void describe(const char *arg, int last_one)
                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);
 
@@ -255,6 +272,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
                OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
                OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
                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",
@@ -263,8 +282,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
        };
 
        argc = parse_options(argc, argv, options, describe_usage, 0);
-       if (max_candidates < 1)
-               max_candidates = 1;
+       if (max_candidates < 0)
+               max_candidates = 0;
        else if (max_candidates > MAX_TAGS)
                max_candidates = MAX_TAGS;
 

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 4ea727b14303e397117067993dbda446ed154ea1..8722a687954ec47a538eff45d41434deedf717fb 100755 (executable)
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -91,7 +91,10 @@ __git_ps1 ()
                        fi
                        if ! b="$(git symbolic-ref HEAD 2>/dev/null)"
                        then
-                               b="$(cut -c1-7 $g/HEAD)..."
+                               if ! b="$(git describe --exact-match HEAD 2>/dev/null)"
+                               then
+                                       b="$(cut -c1-7 $g/HEAD)..."
+                               fi
                        fi
                fi
 

diff --git a/refs.c b/refs.c
index fb33da111240d9a3d579dfebb05eef951fecee23..c979fb1d9507309785909a8d714ab28b1efd2e88 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -157,6 +157,7 @@ static struct cached_refs {
        struct ref_list *loose;
        struct ref_list *packed;
 } cached_refs;
+static struct ref_list *current_ref;
 
 static void free_ref_list(struct ref_list *list)
 {
@@ -476,6 +477,7 @@ static int do_one_ref(const char *base, each_ref_fn fn, int trim,
                error("%s does not point to a valid object!", entry->name);
                return 0;
        }
+       current_ref = entry;
        return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
 }
 
@@ -485,6 +487,16 @@ int peel_ref(const char *ref, unsigned char *sha1)
        unsigned char base[20];
        struct object *o;
 
+       if (current_ref && (current_ref->name == ref
+               || !strcmp(current_ref->name, ref))) {
+               if (current_ref->flag & REF_KNOWS_PEELED) {
+                       hashcpy(sha1, current_ref->peeled);
+                       return 0;
+               }
+               hashcpy(base, current_ref->sha1);
+               goto fallback;
+       }
+
        if (!resolve_ref(ref, base, 1, &flag))
                return -1;
 
@@ -504,7 +516,7 @@ int peel_ref(const char *ref, unsigned char *sha1)
                }
        }
 
-       /* fallback - callers should not call this for unpacked refs */
+fallback:
        o = parse_object(base);
        if (o && o->type == OBJ_TAG) {
                o = deref_tag(o, ref, 0);
@@ -519,7 +531,7 @@ int peel_ref(const char *ref, unsigned char *sha1)
 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
                           void *cb_data)
 {
-       int retval;
+       int retval = 0;
        struct ref_list *packed = get_packed_refs();
        struct ref_list *loose = get_loose_refs();
 
@@ -539,15 +551,18 @@ static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
                }
                retval = do_one_ref(base, fn, trim, cb_data, entry);
                if (retval)
-                       return retval;
+                       goto end_each;
        }
 
        for (packed = packed ? packed : loose; packed; packed = packed->next) {
                retval = do_one_ref(base, fn, trim, cb_data, packed);
                if (retval)
-                       return retval;
+                       goto end_each;
        }
-       return 0;
+
+end_each:
+       current_ref = NULL;
+       return retval;
 }
 
 int head_ref(each_ref_fn fn, void *cb_data)