bug#8084: 24.0.50; grep still relies on font-lock somewhat

[Juri Linkov]

> Do I understand correctly that after revno:104159 (2011-05-08) that
> fixes bug#7952 by handling escape sequences in the process filter
> rather than in font-lock, now the line `(null font-lock-mode)' should be
> removed from `grep-process-setup'

I now think that `grep-process-setup' should still check for
`(null font-lock-mode)' to not output color escapes
that can't be highlighted with `font-lock-face' by `grep-filter'.
There is no harm to output color escapes because `grep-filter'
still removes them, but this is useless because text properties
`font-lock-face' can't be displayed when `font-lock-mode' is nil.

> and this bug#8084 should be closed?

I fixed comments and closed this bug.