update-ca-certificates doesn't concatenate properly certificates if trailing newline is missing
tested with ca-certificates-20171114-r0
If you have a custom PEM certificate that doesn’t have a trailing newline character, the resulting /etc/ssl/certs/ca-certificates.crt will be incorrect and you will find a line such as
-----END CERTIFICATE----------BEGIN CERTIFICATE-----
This results in certificates validation problems which are difficult to diagnose.
Other distributions such as Debian fixed similar reports (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=635570) and behave properly with certificates missing a trailing newline.
(from redmine: issue id 8379, created on 2018-01-04)