bug#13730: 24.3.50; Diff from Bzr-Log-View not highlighted

[Richard Copley]

On 17 February 2013 01:16, Glenn Morris <rgm@gnu.org> wrote:
>
>> Visit a bzr branch, view the root log with "C-x v L", choose a revision
>> and invoke log-view-diff by typing "d". The diff that is shown should be
>> highlighted, but it isn't.
>
> Do you mean that font-locking should be enabled in the *vc-diff* buffer?
> If so, it is for me. (Try bootstrapping?)

That is what I mean, yes. Curious. Did you follow the recipe from
"emacs -Q"? Not all *vc-diff* buffers are affected.

>> The trunk revision in which this stopped working is in (111784,11794].

Make that (111793,111794]. Revision 111794 introduces a new feature in
"easy-mmode.el" that allows major mode functions to disable global
minor modes by explicitly turning off the corresponding minor mode.
Unfortunately font-lock gets turned off in a change-major-mode-hook
function (font-lock-change-mode in "font-core.el"), which doesn't seem
to have been anticipated.

I can't say I understand why this doesn't cause global-font-lock-mode
to be disabled in all major modes in all circumstances. It could be a
question of whether font-lock-change-mode or
global-font-lock-mode-enable-in-buffers is earlier in
change-major-mode-hook.