In visual mode selection is automatically yanked

[nigredo-tori]

1. Install IDEA Community Edition.
2. Install Intellimacs as described in README.md.
3. Use this .ideavimrc (the issue can be reproduced with the default one, but the rest doesn't make a difference):

   source ~/.intellimacs/spacemacs.vim
   

4. Open a file (I have checked this for Scala and BUILD files).
5. Select some text (e. g. V, j, j, j), and press Esc to return to normal mode.
6. Paste (p).
7. See that the previously selected text is pasted, even though it was not yanked by the user!

This is annoying when attempting to replace one piece of text with another. Usually I do it like this:

1. Select and yank the first region.
2. Select the second region.
3. Paste.

This no longer works, since on step 2 I lose the yanked data.

This seems to be an Intellimacs bug because with empty .ideavimrc selection works as expected.