The traveler continues Qasr until either:
• returning to the home town; or
• forming an intention to remain for 15 days or more in a town or village suitable for residence.
If the intention is for less than 15 days — or there is no fixed 15-day intention — the person remains a traveler even if the actual stay becomes very long.
The source does not validate every '15 days somewhere' intention. It gives special cases where residence intention is not legally established.