Wild Brinjal.
Solanum ferox L, "Sour brinjal or Wild brinjal. It goes by the Malay names Terong asam or Terong Dayak unfortunately all those names could equally apply to Solanum macrocarpon which also happens to have similar looking fruits making the identification rather difficult. Solanum lasiocarpum L. is basically a wild or semi-wild species occasionally cultivated for its edible fruits in Southeast Asia in general, New Guinea and Sarawak in particular. The fruits are used in sauces and curries and, like those of most of these (eggplant / nightshade borderline) plants, have a sour taste. This species has some medicinal value as well." from here