Collapse on tr results on tr losing width

Created by: roybrener

Before opening an issue:

Using bootstrap 4-alpha 3 Example: https://github.com/roybrener/tableCollapseBug

I've created a simple table with 2 rows. The 2nd row is hidden using class="collapse". After clicking the first row The second row is being showed but then losses It's width- the FIrst column of row 1 takes much more space and pushes the rest of the columns and the second row gets the width of only the first column.

When removing the "class=collapse" then the row cover the full colSpan

Bootstrap 3 (3.3.7) Works as expected

tested on windows 10- Chrome 53, IE 11.545 and edge, All showing the same behavior