Undesirable sh-mode indent

[Bob Proulx]

In 24.5.1 from Debian Sid I am now getting undesirable indention that
is no longer controlled by sh-basic-offset.  In 23 this worked.

emacs -Q /tmp/trial.sh

M-: (setq sh-basic-offset 2)

if true; then
    true
    ^ indent should be 2 not 4 here

C-c ?
Rules used: :elem basic -> 4, :before "then" -> 0, :after "then" -> nil

Anyone know what is happening here?  I have reviewed the NEWS but I
didn't find any intentionally noted changes here.

Does anyone know how to keep syntax highlighting but to disable
indentation?  Then at least I could at least stop it from doing the
wrong thing without dropping all of the way to fundamental-mode.

Thanks,
Bob