This is the British, not Indian, pattern, with rounded upper pocket flaps and no bellows in the pocket. Made in an open "cellular" weave called Aertex, it provides better ventilation than traditional weave fabrics. British nomenclature was Bush Shirt, possibly because it could worn with the taail tucked in to short or trousers to wear as a shirt.
This bush jacket was standard issue to Other Ranks in North Africa from 1943, and was also worn extensively in Sicily, Italy, and the Mediterranean. Paras in the Med theatre often wore this bush jacket with denim battledress trousers.