ap: set default repodir

if there are an APKBUILD in current dir, then use ../ as repodir.
Otherwise, use cwd as repodir.

Introduces requirement of lua-filesystem

ap.in

@@ -1,6 +1,7 @@
 #!/usr/bin/lua
 
 require("aports")
+require("lfs")
 
 local db
 
@@ -105,6 +106,14 @@ if cmd == nil then
 	return
 end
 
+if #repodirs == 0 then
+	if lfs.attributes("APKBUILD") then
+		repodirs[1] = string.gsub(lfs.currentdir(), "(.*)/.*", "%1")
+	else
+		repodirs[1] = lfs.currentdir()
+	end
+end
+
 if subcmd[cmd] and type(subcmd[cmd].run) == "function" then
 	db = aports.new(repodirs)
 	subcmd[cmd].run(opts)