It seems that the focus construction N the one wa ___ often takes the place of cleft-constructions of the 'It is N who ___' type; the latter has been reported in Mufwene (2004: 368). This is an obvious calque on the English focus construction of the type 'John is the one who has your book (not Jack).' In this case the one could be called a dummy NP predicate. This construction would not normally be called a cleft, but it qualifies as one under the definition given for this feature.
Source: Anonymous 2005: 315