(defun sh-smie--default-backward-token ()

[...]

            (progn (skip-syntax-backward ".w_'")

                   (or (not (zerop (skip-syntax-backward "\\")))

                       (when (eq ?\\ (char-before (1- (point))))

Semi-colons have punctuation syntax, so we're skipping back over the

entirety of "test;then" instead of stopping after "then".

We should indeed only skip over "then", and then only over ";" and then

only over "test".

This looks easy enough to fix, but the overall logic of that function is

somewhat obscure to me, so I've added Stefan to the comments; perhaps he

has some comments.

The sh syntax is fairly nasty to parse, especially backwards, so I can't

give you any general comment here.  I'd try something and then see if it

breaks any tests (including looking at test/manual/indent/shell.sh).

For sure, I'd recommend adding a regression test.

        Stefan