bug#18856: 24.4; *grep* output buffer not getting fontified when jit-lock-defer-time is used

[David Engster]

Recipe:

* emacs -Q

* M-x set-variable RET jit-lock-defer-time RET 0.05 RET

* Call M-x rgrep and search for some string in some directory

You should be able to see that the *grep* buffer capturing grep's output
is not getting fontified until you hit a key. I would expect that it
gets fontified automatically when new output arrives.

Note that the same problem happens for other buffers which capture
process output, like compilation buffers.

-David