Mouseup outside of modal during text selection closes modal

[clarkwinkelmann]

Steps to reproduce:

1. Open a modal (any modal from the example page works)
2. Select text (paragraphs or input text) with the mouse by clicking and dragging
3. Select until the end of the line by dragging the cursor further than the start or end of text
4. Release cursor while it's above the modal backdrop

Expected: the text is selected and can be copied. Or in the case of an input, ready to be edited

Actual: the modal closes

The same behaviour does not happen in regular bootstrap with jquery