Hi Ikumi,

> Is `reftex-TeX-master-file' the only source of RefTeX non-file buffer
> difficulties? If so, I expect there is a possibility that we can amend
> it so that RefTeX would not stumble in non-file buffer. For example,
> `TeX-master-file' returns "<none>.tex" if it can't find a sensible
> master file. What if we implement similar fallback for
> `reftex-TeX-master-file'?

Patching reftex in the suggested way does seem to alleviate the noted
issue with style hooks.  I can only imagine it breaks other things, but
given that non-file buffers are already not supported in reftex, maybe
that's OK?

Paul