Description of problem:

Using Edit->Track Changes->Compare Document in conjunction with the GTK3 VCL seems to cause an infinite loop where the file chooser widget cannot be closed. I cannot reproduce the problem with any VCL other than the GTK3 one. (I tried GTK2 and KDE4, and there's no such issue when those are used instead.)

Version-Release number of selected component (if applicable):

5.1.5.2-5.fc24

How reproducible:

Always.

Steps to Reproduce:
1. Open a document.
2. Use Edit->Track Changes->Compare Document to select a different version of the document (or anything unrelated, of course).
3. Select a document with the file chooser widget.
4. The Manage Changes widget pops up. Click on "close".
5. Note the file chooser widget doesn't close as it should, and seemingly refuses to go away.

Actual results:

The file chooser widget will not close, no matter how many times I click on "cancel" or "open". I have to close LibreOffice to start over.

Expected results:

The file chooser widget should close along with the Manage Changes widget when "close" is clicked in the latter. This is the normal behaviour with other VCLs.

Additional info:

This is occurring under X. I haven't tested under Wayland.