[Samba] "Read only" error behaviour differences between samba versions

[Rory Falloon]

Hello,

Whilst upgrading from Samba 3.6.4 to Samba 4.10.16 (Centos 7.9), I have
observed the Windows UI acting differently when trying to write a new
folder/file to path that is, at the samba server level (and below that,
since it is a samba share of a NFS export), read only.

When using samba 3.6.4, the error in logs generated is
NT_STATUS_ACCESS_DENIED. The UI generates a pop up stating "you need
permission to perform this action".  This appears (in my opinion) to be a
"normal" pop up and one that is easily understood by the end user.

When using samba 4.10.16, the error in the logs generated
is NT_STATUS_MEDIA_WRITE_PROTECTED. The UI generates a pop up stating "An
unexpected error is keeping you from creating the folder. If you continue
to receive this error,  you can use the error code to search for help with
this problem. Error 0x8000FFFF: Catastrophic failure".  This sounds much
worse than it is, in this instance...

The command shell on both versions generates "The media is write protected."

It's of course not expected to write to this directory (exported read only)
by design, so this is more a question of cosmetics, but can someone comment
when this was changed,  and why? is there a changelog or bug that I can
reference? I have not been able to find anything concrete on this.