Steps to reproduce the behavior:
Does not happen using right-click -> paste.
JabRef 5.0 DEV, 85e684b5e6c04c8f47834b3c0a960a9c53d00a3c
Mac OS X 10.14.3 x86_64
Java 1.8.0_191
Cannot confirm under windows. Please try java 8u202 as there have been several bug fixes for mac:
https://www.oracle.com/technetwork/java/javase/2col/8u202-bugfixes-5209341.html
It still persists with latest (1.8u202) Oracle JDK.
Addon: If an entry is pasted into the maintable it is also pasted twice
Reproduced this bug, start to work on it.
Thanks to @LinusDietz and @stefan-kolb this issue is now fixed in the latest master!
Most helpful comment
Reproduced this bug, start to work on it.