for-each-ref --format='%(symref) %(symref:short)'

New %(symref) output atom expands to the name of the ref a symbolic ref
points at, or an empty string if the ref being shown is not a symref.

This may help scripted Porcelain writers.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-for-each-ref.c b/builtin-for-each-ref.c
index d68977ee63c6ad604e7d98c9966909c708ba7b9b..b9b03e14d3f6a6cedb6cf6363d55e4d564cc3d28 100644 (file)
--- a/builtin-for-each-ref.c
+++ b/builtin-for-each-ref.c
@@ -33,6 +33,8 @@ struct ref_sort {
 struct refinfo {
        char *refname;
        unsigned char objectname[20];
+       int flag;
+       const char *symref;
        struct atom_value *value;
 };
 
@@ -68,6 +70,7 @@ static struct {
        { "body" },
        { "contents" },
        { "upstream" },
+       { "symref" },
 };
 
 /*
@@ -82,7 +85,7 @@ static struct {
  */
 static const char **used_atom;
 static cmp_type *used_atom_type;
-static int used_atom_cnt, sort_atom_limit, need_tagged;
+static int used_atom_cnt, sort_atom_limit, need_tagged, need_symref;
 
 /*
  * Used to parse format string and sort specifiers
@@ -135,6 +138,8 @@ static int parse_atom(const char *atom, const char *ep)
        used_atom_type[at] = valid_atom[i].cmp_type;
        if (*atom == '*')
                need_tagged = 1;
+       if (!strcmp(used_atom[at], "symref"))
+               need_symref = 1;
        return at;
 }
 
@@ -566,6 +571,16 @@ static void populate_value(struct refinfo *ref)
 
        ref->value = xcalloc(sizeof(struct atom_value), used_atom_cnt);
 
+       if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
+               unsigned char unused1[20];
+               const char *symref;
+               symref = resolve_ref(ref->refname, unused1, 1, NULL);
+               if (symref)
+                       ref->symref = xstrdup(symref);
+               else
+                       ref->symref = "";
+       }
+
        /* Fill in specials first */
        for (i = 0; i < used_atom_cnt; i++) {
                const char *name = used_atom[i];
@@ -581,6 +596,8 @@ static void populate_value(struct refinfo *ref)
 
                if (!prefixcmp(name, "refname"))
                        refname = ref->refname;
+               else if (!prefixcmp(name, "symref"))
+                       refname = ref->symref ? ref->symref : "";
                else if (!prefixcmp(name, "upstream")) {
                        struct branch *branch;
                        /* only local branches may have an upstream */
@@ -726,6 +743,7 @@ static int grab_single_ref(const char *refname, const unsigned char *sha1, int f
        ref = xcalloc(1, sizeof(*ref));
        ref->refname = xstrdup(refname);
        hashcpy(ref->objectname, sha1);
+       ref->flag = flag;
 
        cnt = cb->grab_cnt;
        cb->grab_array = xrealloc(cb->grab_array,