Merge branch 'es/clone-shared-worktree'

"git clone --shared" to borrow from a (secondary) worktree did not
work, even though "git clone --local" did.  Both are now accepted.

* es/clone-shared-worktree:
  clone: support 'clone --shared' from a worktree

builtin/clone.c

@@ -452,7 +452,8 @@ static void clone_local(const char *src_repo, const char *dest_repo)
 {
 	if (option_shared) {
 		struct strbuf alt = STRBUF_INIT;
-		strbuf_addf(&alt, "%s/objects", src_repo);
+		get_common_dir(&alt, src_repo);
+		strbuf_addstr(&alt, "/objects");
 		add_to_alternates_file(alt.buf);
 		strbuf_release(&alt);
 	} else {