Based on this site you are French if

• one of your parent on your birth certificate is French when you were born
• one of your parent on your birth certificate becomes French while you are still a minor and unmarried (for example they get their citizenship later by naturalization). In this case you have to be a resident in French to get your parent's citizenship, or you have to be a resident in French for at least 5 years as a minor if you are living abroad at the moment. If you are allowed to get French nationality based on this or the previous criteria, then it doesn't matter if your parent loses French nationality later.
• you were born in France, and one of your parent is also born in France (doesn't need to have French nationality though)
• you were born in France and at least one of your parents was born in Algeria, before the 3rd July 1962
• you were adopted by a French national in France

Based on this site you are French if

• one of your parent on your birth certificate is French when you were born
• one of your parent on your birth certificate becomes French while you are still a minor and unmarried (for example they get their citizenship later by naturalization). In this case you have to be a resident in France to get your parent's citizenship, or you have to be a resident in France for at least 5 years as a minor if you are living abroad at the moment. If you are allowed to get French nationality based on this or the previous criteria, then it doesn't matter if your parent loses French nationality later.
• you were born in France, and one of your parent is also born in France (doesn't need to have French nationality though)
• you were born in France and at least one of your parents was born in Algeria, before the 3rd July 1962
• you were adopted by a French national in France