t.setUndefinedRegion(Region(x.region))
				t.setUndefinedLang(Language(x.lang))
				return t, nil
			}
		}
		// Search matches for und-region. If und-script-region exists, it would
		// have been found earlier.
		if t.RegionID != 0 {
			if i := regionInclusion[t.RegionID]; i < nRegionGroups {
				x := likelyRegionGroup[i]
				if x.region != 0 {
					t.setUndefinedLang(Language(x.lang))