Created attachment 136801 [details]
Please have a look at the attached screenshot. If I paste as "Unformatted text" into a comment the result is formatted.
Source for CTRL+C is cell A1 in my example.
Build ID: 34f4446b0a5e04465216ff4ec2547aa82e0f06c2
CPU threads: 2; OS: Linux 4.4; UI render: default; VCL: gtk2;
Locale: en-US (en_US.UTF-8); Calc: group
*** This bug has been marked as a duplicate of bug 46999 ***
The equivalent report for Writer is bug bug 46999.
Maxim Monastirsky committed a patch related to this issue.
It has been pushed to "master":
tdf#112935 Paste as Unformatted doesn't work in shapes and comments
It will be available in 6.2.0.
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.