/* We allow "recursive" symbolic refs. Only within reason, though */
#define MAXDEPTH 5
+#define MAXREFLEN (1024)
+
+static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
+{
+ FILE *f;
+ struct cached_refs refs;
+ struct ref_list *ref;
+ int retval;
+
+ strcpy(name + pathlen, "packed-refs");
+ f = fopen(name, "r");
+ if (!f)
+ return -1;
+ read_packed_refs(f, &refs);
+ fclose(f);
+ ref = refs.packed;
+ retval = -1;
+ while (ref) {
+ if (!strcmp(ref->name, refname)) {
+ retval = 0;
+ memcpy(result, ref->sha1, 20);
+ break;
+ }
+ ref = ref->next;
+ }
+ free_ref_list(refs.packed);
+ return retval;
+}
+
+static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
+{
+ int fd, len = strlen(refname);
+ char buffer[128], *p;
+
+ if (recursion > MAXDEPTH || len > MAXREFLEN)
+ return -1;
+ memcpy(name + pathlen, refname, len+1);
+ fd = open(name, O_RDONLY);
+ if (fd < 0)
+ return resolve_gitlink_packed_ref(name, pathlen, refname, result);
+
+ len = read(fd, buffer, sizeof(buffer)-1);
+ close(fd);
+ if (len < 0)
+ return -1;
+ while (len && isspace(buffer[len-1]))
+ len--;
+ buffer[len] = 0;
+
+ /* Was it a detached head or an old-fashioned symlink? */
+ if (!get_sha1_hex(buffer, result))
+ return 0;
+
+ /* Symref? */
+ if (strncmp(buffer, "ref:", 4))
+ return -1;
+ p = buffer + 4;
+ while (isspace(*p))
+ p++;
+
+ return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
+}
+
+int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
+{
+ int len = strlen(path), retval;
+ char *gitdir;
+
+ while (len && path[len-1] == '/')
+ len--;
+ if (!len)
+ return -1;
+ gitdir = xmalloc(len + MAXREFLEN + 8);
+ memcpy(gitdir, path, len);
+ memcpy(gitdir + len, "/.git/", 7);
+
+ retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
+ free(gitdir);
+ return retval;
+}
const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
{