bug#19548: VC changes under-documented, needlessly incompatible

[Dmitry Gutov]

On 05/24/2016 06:34 PM, Eli Zaretskii wrote:

> Yes, it looks good to me.

Pushed, thanks. If someone would like to point out what else we're 
missing in this bug, that would be great.

I've glanced through the "Changes from the pre-25.1 API" list, and one 
change we could make to improve backward compatibility there, is to 
catch wrong-number-of-arguments when calling the `diff' method, and 
retry with one fewer argument.

Doesn't really seem worth the trouble, however. The list of changes is 
longer than that, and third-party backends will have to adapt anyway.

Similarly, the change to dir-status-files could be smoothed over by 
continuing to pass some dummy fourth argument, but it's unclear when 
we'd be allowed to stop doing that. So maybe not doing that at all is 
just as valid an option. IIRC, nobody has really complained about their 
backend having stopped working.

> You can try this one:
>
>   http://www.delorie.com/djgpp/cvs.html

Thanks. revert-buffer works *very* slowly with it using the default 
settings, but at least the results look correct.