Re: c-mode seems broken

[Alan Mackenzie <acm@muc.de>]

Francis Moreau <francis.moro@gmail.com> wrote:
> Hello,

> Since a couple of months (I don't remember when exactly I first
> encounter this), the indentation stop working when editing a C source
> file. That is when I press <TAB> the line is indented at the start of
> the line (instead of inserting an appropriate number of spaces). To
> workaround this problem I do "M-x c-mode" and the indentation is
> working again.

> It seems that happens after adding/modifying code inside "#ifdef/
> #endif", but I'm not sure.

This is a known problem which has been fixed (by removing an
"improvement") in the soon-to-be-released Emacs 23.2.  The "improvement"
itself has been fixed for the medium future Emacs 24.

The bug is triggered by inserting a newline at the end of any C
preprocessor line.  This wrongly pushes a "CPP marker" (actually a text
property) onto the start of the next line.

> How can I fix this ?

Upgrade to Emacs 23.2 when it gets released.  This could be as early as
the coming Friday.

Sorry for this bug.

> Thanks

-- 
Alan Mackenzie (Nuremberg, Germany).