SubmittingPatches: document how to reference previous commits

diff --git a/tag.c b/tag.c
index 330d287924765c95dac428f040b104930c316b81..d72f742af9a4a6a76c8b0f6fd314473dea244b2a 100644 (file)
--- a/tag.c
+++ b/tag.c
@@ -9,7 +9,10 @@ const char *tag_type = "tag";
 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
 {
        while (o && o->type == OBJ_TAG)
-               o = parse_object(((struct tag *)o)->tagged->sha1);
+               if (((struct tag *)o)->tagged)
+                       o = parse_object(((struct tag *)o)->tagged->oid.hash);
+               else
+                       o = NULL;
        if (!o && warn) {
                if (!warnlen)
                        warnlen = strlen(warn);
@@ -18,59 +21,70 @@ struct object *deref_tag(struct object *o, const char *warn, int warnlen)
        return o;
 }
 
+struct object *deref_tag_noverify(struct object *o)
+{
+       while (o && o->type == OBJ_TAG) {
+               o = parse_object(o->oid.hash);
+               if (o && o->type == OBJ_TAG && ((struct tag *)o)->tagged)
+                       o = ((struct tag *)o)->tagged;
+               else
+                       o = NULL;
+       }
+       return o;
+}
+
 struct tag *lookup_tag(const unsigned char *sha1)
 {
        struct object *obj = lookup_object(sha1);
        if (!obj)
-               return create_object(sha1, OBJ_TAG, alloc_tag_node());
-       if (!obj->type)
-               obj->type = OBJ_TAG;
-        if (obj->type != OBJ_TAG) {
-                error("Object %s is a %s, not a tree",
-                      sha1_to_hex(sha1), typename(obj->type));
-                return NULL;
-        }
-        return (struct tag *) obj;
+               return create_object(sha1, alloc_tag_node());
+       return object_as_type(obj, OBJ_TAG, 0);
+}
+
+static unsigned long parse_tag_date(const char *buf, const char *tail)
+{
+       const char *dateptr;
+
+       while (buf < tail && *buf++ != '>')
+               /* nada */;
+       if (buf >= tail)
+               return 0;
+       dateptr = buf;
+       while (buf < tail && *buf++ != '\n')
+               /* nada */;
+       if (buf >= tail)
+               return 0;
+       /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
+       return strtoul(dateptr, NULL, 10);
 }
 
-int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
+int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
 {
-       int typelen, taglen;
        unsigned char sha1[20];
-       const char *type_line, *tag_line, *sig_line;
        char type[20];
+       const char *bufptr = data;
+       const char *tail = bufptr + size;
+       const char *nl;
 
-        if (item->object.parsed)
-                return 0;
-        item->object.parsed = 1;
+       if (item->object.parsed)
+               return 0;
+       item->object.parsed = 1;
 
        if (size < 64)
                return -1;
-       if (memcmp("object ", data, 7) || get_sha1_hex((char *) data + 7, sha1))
-               return -1;
-
-       type_line = (char *) data + 48;
-       if (memcmp("\ntype ", type_line-1, 6))
+       if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
                return -1;
+       bufptr += 48; /* "object " + sha1 + "\n" */
 
-       tag_line = strchr(type_line, '\n');
-       if (!tag_line || memcmp("tag ", ++tag_line, 4))
+       if (!starts_with(bufptr, "type "))
                return -1;
-
-       sig_line = strchr(tag_line, '\n');
-       if (!sig_line)
+       bufptr += 5;
+       nl = memchr(bufptr, '\n', tail - bufptr);
+       if (!nl || sizeof(type) <= (nl - bufptr))
                return -1;
-       sig_line++;
-
-       typelen = tag_line - type_line - strlen("type \n");
-       if (typelen >= 20)
-               return -1;
-       memcpy(type, type_line + 5, typelen);
-       type[typelen] = '\0';
-       taglen = sig_line - tag_line - strlen("tag \n");
-       item->tag = xmalloc(taglen + 1);
-       memcpy(item->tag, tag_line + 4, taglen);
-       item->tag[taglen] = '\0';
+       memcpy(type, bufptr, nl - bufptr);
+       type[nl - bufptr] = '\0';
+       bufptr = nl + 1;
 
        if (!strcmp(type, blob_type)) {
                item->tagged = &lookup_blob(sha1)->object;
@@ -85,11 +99,21 @@ int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
                item->tagged = NULL;
        }
 
-       if (item->tagged && track_object_refs) {
-               struct object_refs *refs = alloc_object_refs(1);
-               refs->ref[0] = item->tagged;
-               set_object_refs(&item->object, refs);
-       }
+       if (bufptr + 4 < tail && starts_with(bufptr, "tag "))
+               ;               /* good */
+       else
+               return -1;
+       bufptr += 4;
+       nl = memchr(bufptr, '\n', tail - bufptr);
+       if (!nl)
+               return -1;
+       item->tag = xmemdupz(bufptr, nl - bufptr);
+       bufptr = nl + 1;
+
+       if (bufptr + 7 < tail && starts_with(bufptr, "tagger "))
+               item->date = parse_tag_date(bufptr, tail);
+       else
+               item->date = 0;
 
        return 0;
 }
@@ -103,14 +127,14 @@ int parse_tag(struct tag *item)
 
        if (item->object.parsed)
                return 0;
-       data = read_sha1_file(item->object.sha1, &type, &size);
+       data = read_sha1_file(item->object.oid.hash, &type, &size);
        if (!data)
                return error("Could not read %s",
-                            sha1_to_hex(item->object.sha1));
+                            oid_to_hex(&item->object.oid));
        if (type != OBJ_TAG) {
                free(data);
                return error("Object %s not a tag",
-                            sha1_to_hex(item->object.sha1));
+                            oid_to_hex(&item->object.oid));
        }
        ret = parse_tag_buffer(item, data, size);
        free(data);