I was filling up the application for the Canadian Visitor Visa for my grandfather. The application form (IMM5257e) asks for the 'Place of Birth' in which we can type in the city/town but have to choose the country from a drop down list.
The instructions for filling the form as mentioned in Govt. of Canada's site say
Question 5: Note, if your city, town, or country or territory of birth is indicated in your passport or your travel document, please record it as it appears in the document.
Now, my grandfather is an Indian citizen but was born in Lahore (Present day Pakistan) before the partition so his passport mentions the place of birth as Lahore, Undivided India.
What do I put in the country? India, as at that time Lahore was the part of British India, or Pakistan, where the place currently exists.
All his previous passports mention (going back to the 60s) either mention West Pakistan or Undivided India - Countries which don't exist anymore - and not countries which exist i.e. India or Pakistan.
He hasn't traveled much in the past decade and most of the applications at his time were paper based where he could've just wrote whatever it was in his passport so it was never a problem.