Re: cannot activate font-lock-mode

[Chong Yidong]

Richard Stallman <address@hidden> writes:

> Should this fix be installed in Emacs 22.1?
> Or is it safer for us to leave that bug unfixed?

I suggest not patching Emacs 22.1 at this time.

First, this only affects setting font-lock-keywords in local
variables, which is an advanced user activity that we generally
discourage for security reasons; that is why font-lock-keywords is
marked risky.

Second, allowing file local variables to change font-lock-keywords
seems to violate an implicit assumption made in font-lock that
font-lock-keywords is managed by font-lock, and set by either
major/minor modes or by higher-level variables such as
font-lock-defaults.  That assumption is why font-lock-set-defaults
inadvertently wipes out the font-lock-keywords set by file-local
variables.  This may be a simple oversight made when revamping
font-lock-keywords earlier in the development cycle, but this just
emphasizes the fact that this behavior is delicate.  So I think
changing it is risky at this stage.

Third, for those advanced users that want this feature, there are many
ways to work around this problem: calling font-lock-add-keyword using
an eval in the file variables section, using hi-lock-mode, etc.