RFR 8247960: jarsigner says "signer errors" for some normal warnings when -strict is set

[Hai-May Chao]

Hi,

I’d like to request a review for:

JBS: https://bugs.openjdk.java.net/browse/JDK-8247960
Webrev: https://cr.openjdk.java.net/~hchao/8247960/webrev.00/

Jarsigner is changed to emit “with signer errors” only when there are errors 
detected during sign and verify with -strict specified.

Thanks,
Hai-May