ref-filter: libify get_ref_atom_value()

Finish removing die() calls from ref-filter formatting logic,
so that it could be used by other commands.

Change the signature of get_ref_atom_value() and underlying functions
by adding return value and strbuf parameter for error message.
Return value equals 0 upon success and -1 upon failure.
Upon failure, error message is appended to the strbuf.

Signed-off-by: Olga Telezhnaia <olyatelezhnaya@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/ref-filter.c b/ref-filter.c
index 3f85ef64267d958dba79aefdc38e6958d6a47e94..3bc65e49358eed2c2f4a895af95a37c9831ef55c 100644 (file)
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -1427,28 +1427,30 @@ static const char *get_refname(struct used_atom *atom, struct ref_array_item *re
        return show_ref(&atom->u.refname, ref->refname);
 }
 
-static void get_object(struct ref_array_item *ref, const struct object_id *oid,
-                      int deref, struct object **obj)
+static int get_object(struct ref_array_item *ref, const struct object_id *oid,
+                      int deref, struct object **obj, struct strbuf *err)
 {
        int eaten;
+       int ret = 0;
        unsigned long size;
        void *buf = get_obj(oid, obj, &size, &eaten);
        if (!buf)
-               die(_("missing object %s for %s"),
-                   oid_to_hex(oid), ref->refname);
-       if (!*obj)
-               die(_("parse_object_buffer failed on %s for %s"),
-                   oid_to_hex(oid), ref->refname);
-
-       grab_values(ref->value, deref, *obj, buf, size);
+               ret = strbuf_addf_ret(err, -1, _("missing object %s for %s"),
+                                     oid_to_hex(oid), ref->refname);
+       else if (!*obj)
+               ret = strbuf_addf_ret(err, -1, _("parse_object_buffer failed on %s for %s"),
+                                     oid_to_hex(oid), ref->refname);
+       else
+               grab_values(ref->value, deref, *obj, buf, size);
        if (!eaten)
                free(buf);
+       return ret;
 }
 
 /*
  * Parse the object referred by ref, and grab needed value.
  */
-static void populate_value(struct ref_array_item *ref)
+static int populate_value(struct ref_array_item *ref, struct strbuf *err)
 {
        struct object *obj;
        int i;
@@ -1570,16 +1572,17 @@ static void populate_value(struct ref_array_item *ref)
                        break;
        }
        if (used_atom_cnt <= i)
-               return;
+               return 0;
 
-       get_object(ref, &ref->objectname, 0, &obj);
+       if (get_object(ref, &ref->objectname, 0, &obj, err))
+               return -1;
 
        /*
         * If there is no atom that wants to know about tagged
         * object, we are done.
         */
        if (!need_tagged || (obj->type != OBJ_TAG))
-               return;
+               return 0;
 
        /*
         * If it is a tag object, see if we use a value that derefs
@@ -1593,20 +1596,23 @@ static void populate_value(struct ref_array_item *ref)
         * is not consistent with what deref_tag() does
         * which peels the onion to the core.
         */
-       get_object(ref, tagged, 1, &obj);
+       return get_object(ref, tagged, 1, &obj, err);
 }
 
 /*
  * Given a ref, return the value for the atom.  This lazily gets value
  * out of the object by calling populate value.
  */
-static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom_value **v)
+static int get_ref_atom_value(struct ref_array_item *ref, int atom,
+                             struct atom_value **v, struct strbuf *err)
 {
        if (!ref->value) {
-               populate_value(ref);
+               if (populate_value(ref, err))
+                       return -1;
                fill_missing_values(ref->value);
        }
        *v = &ref->value[atom];
+       return 0;
 }
 
 /*
@@ -2130,9 +2136,13 @@ static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, stru
        int cmp;
        cmp_type cmp_type = used_atom[s->atom].type;
        int (*cmp_fn)(const char *, const char *);
+       struct strbuf err = STRBUF_INIT;
 
-       get_ref_atom_value(a, s->atom, &va);
-       get_ref_atom_value(b, s->atom, &vb);
+       if (get_ref_atom_value(a, s->atom, &va, &err))
+               die("%s", err.buf);
+       if (get_ref_atom_value(b, s->atom, &vb, &err))
+               die("%s", err.buf);
+       strbuf_release(&err);
        cmp_fn = s->ignore_case ? strcasecmp : strcmp;
        if (s->version)
                cmp = versioncmp(va->s, vb->s);
@@ -2210,12 +2220,8 @@ int format_ref_array_item(struct ref_array_item *info,
                if (cp < sp)
                        append_literal(cp, sp, &state);
                pos = parse_ref_filter_atom(format, sp + 2, ep, error_buf);
-               if (pos < 0) {
-                       pop_stack_element(&state.stack);
-                       return -1;
-               }
-               get_ref_atom_value(info, pos, &atomv);
-               if (atomv->handler(atomv, &state, error_buf)) {
+               if (pos < 0 || get_ref_atom_value(info, pos, &atomv, error_buf) ||
+                   atomv->handler(atomv, &state, error_buf)) {
                        pop_stack_element(&state.stack);
                        return -1;
                }