Latest master has the buttons on the document save dialog swapped, so if you create e.g. a new Writer doc, type in some characters and press ^W, then "right arrow, then Enter" no longer means "don't save".
Bibisect says the range is a148fe149c7af1995fd2aaab0a6e52242509b993..41d90d6c7c41df781ecaf7745872f20abd7e52a9, likely 6c80a8fe89fadf9a2c7260a09c037a09462f53d1.
Created attachment 120520 [details]
Good / old output.
Created attachment 120521 [details]
Bad / new output.
is_kde5_desktop() in vcl returns true if version is not 5, that's how kde4 gets detected as kde5.
Miklos Vajna committed a patch related to this issue.
It has been pushed to "master":
tdf#95795 vcl: fix KDE5 desktop detection
It will be available in 5.1.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.