On 2012-05-16 00:50 +0800, Alan Mackenzie wrote:
> I don't think this is a bug.  When you've read that manual page, would
> you please check exactly what you've done, and whether your buffer
> indents as we both would like.

I have read the manual before and I just read it again. Here is a
detailed recipe to reproduce:

1. Emacs -q
2. Make a new buffer named BUG and enable c-mode in it
3. C-c C-o and customise syntactic 'c' to 4 in BUG buffer
4. Now typing in the BUG buffer slash star /*, then press M-j
5. type TAB to indent

In step 4 the buffer looks like: