Re: Recent diff-mode changes feel slow with TRAMP

[Juri Linkov <juri@linkov.net>]

>> When a remote host is fast, it's a big advantage that TRAMP supports
>> this feature without any efforts.  But when a remote host is slow,
>> it should be disabled indeed.
>>
>> I can't confirm what effect is has on slow connections because all my
>> remote connections are so fast that I don't notice any difference
>> between remote and local.
>
> Do you think it would be possible to provide a fast/local option for
> diff-font-lock-syntax which doesn't fetch the base file but still
> performs some syntax-highlighting (e.g. just take the hunk's text into
> a temp buffer, put it in the appropriate major mode and
> call font-lock-ensure;

There is already an option `hunk-only' but I don't know how
TRAMP could detect a slow connection and set diff-font-lock-syntax
to `hunk-only' in this case.

>                        maybe bailing out if the end of the hunk is
> taken to be within a string, in which case maybe the whole highlighting
> was done wrong because maybe it was the beginning of the hunk which was
> inside a string)?

Also I don't know how to detect a partial string because if there are
two unterminated strings (i.e. two quotes) in the same hunk
they might be interpreted as one "inside-out" string.