What is the history of the IndianEnglish usage of "doubt" to mean "question"?

The root of this usage can perhaps be traced to one Indian word: Shankaa. The word Shankaa does represent doubt with the sense as in British English. However, it does get used to convey one more sense: a state of 'confusion', i.e., partial understanding enough to make one capable of seeking a clarification. Often this state doesn't get referred to as a state of having a question in mind, since the question itself may not be very clear and precise, and it may also be an invalid one. Secondly, questioning also sounds like being a bit aggressive, conveying a feeling of posing as a challenger. Posing doubts sounds more polite and correct. So, the teachers ask questions and the students have doubts for clarification! Thus, Doubt when used to represent a question becomes more friendlier than Question.