If a fasting person wakes up and finds food in his mouth
Question

                I used to smoke but Alhamdulillah I gave up smoking. The problem is that whenever I feel that I desire smoking I chew a part of the cigarette to kill this desire, but it did not help. Anyway, I was chewing it in a night of Ramadaan and I fell asleep while it was in my mouth, I woke up after Fajr and washed my mouth. Did this invalidate my fasting that day?.
Praise be to Allah.If dawn breaks and there is 
    something in the fasting person’s mouth and he spits it out, but he does not 
    willingly swallow any of it, then his fast is valid. Al-Nawawi (may Allaah 
    have mercy on him) said in al-Minhaaj: If dawn breaks and there is 
    some food in his mouth and he spits it out, his fast is valid. It says in 
    Mughni al-Muhtaaj (2/161): Because if he put it in his mouth during the 
    day it would not invalidate the fast, so it is more likely that this is the 
    case if he put it in his mouth at night. But if he swallows any part of it 
    deliberately, then he had broken his fast. End quote. 
Secondly: 
Doctors and researchers 
    have warned against chewing tobacco, and they have stated that this is not 
    regarded as a safe alternative to smoking; rather it is more dangerous and 
    more harmful to the body than smoking in some ways, because it exposes the 
    body to the risk of cancer more than smoking. 
What the one who has 
    decided to give up smoking should do is to give it up completely and seek 
    the help of Allaah with regard to that. It has been proven by experiments 
    and experience that it is possible to stop smoking and that giving it up is 
    easy. What matters is to repent sincerely and have strong willpower. 
We ask Allaah to help and 
    guide us and you. 
And Allaah knows best.