Bootstrap 3 modal fires and causes page to shift to the left momentarily / browser scroll bar problems

Question

I am working on a site using Bootstrap 3.1.0.

You'll notice when the modal window opens, the browser scroll bar just disappears for a split second, then comes back. It does the same when you close it.

How can I make it so that it just open and closes with no browser scroll bar interaction. I have seen posts on stack where people were having problems, but I can't find an answer specific to my problem, so if someone else has made this request and someone knows about it and wants to link me to it, I'd appreciate it. I've searched for about 2 hours for this before posting up.

Answer 1

.modal {
 overflow-y: auto;
}

.modal-open {
 overflow: auto;
}

Will get rid of it. This was added to make the modals work more responsively, so you could scroll down and see a modal if the screen was too short. It also stops the background from being scrollable while a modal is up. If you don't need that functionality, then you can use that css I posted.

Some more info: They are setting .modal-open on the body, which prevents all scrolling on the body and hides the body scrollbar. Then, when the modal comes up it has the dark background that takes up the whole screen, and that has overflow-y: scroll which forces the scrollbar to come back so if the modal extended passed the bottom of the screen you can still scroll the dark background and see the rest of it.