bug#3688: Also need (auto-fill-mode nil) to trigger this bug

[Kees Bakker]

Hi,

In my report I forgot to run emacs with -Q, but the problem is still
present with -Q. But here is extra information to reproduce the error.

After entering the suggested C text (and emacs is in a basic C mode)
you have to evaluate the following before the error can be reproduced.
   (auto-fill-mode nil)

In the status bar it shows "*C/l Abbrev Fill)". In the buffer you'll
have the following.

   /*type a space here=>
   /* 3 tabs following after this=>                     */

(Notice that there are 3 TABs before the closing C comment.)
If you type a space on the first comment line, you'll see that it jumps
back 21 positions.

If you evaluate this again, the problem goes away.
   (auto-fill-mode nil)
Now, the "Fill" flag is gone from the status bar.

Kind regards,
Kees Bakker