I have the current daily master build installed on Linux Mint 17, with the local helppack (Version: 22.214.171.124.alpha1+ Build ID: 9c08a06f5d399a7cd11849a377a82663ef6a528e TinderBox: Linux-rpm_deb-x86_64@46-TDF, Branch:master, Time: 2015-05-15_01:42:11 Locale: en-US (en_US.UTF-8)). When document and help windows are open, closing either window closes both. If a document is open, the termination is a crash and leads to the document recovery process.
known problem : see bug 91259
Best regards. JBF
*** This bug has been marked as a duplicate of bug 91259 ***