Re: [PATCH v4] gc: call "prune --expire 2.weeks.ago" by default

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> > ---prune::
> 
> I am fairly paranoid about end users wondering about what is described in
> ancient documentation and complaining that we do not talk about it
> anymore.  I am tempted to suggest:
> 
> 	This is a no-op but you may see it mentioned in older docs and
> 	scripts.  Older git-gc never ran 'prune' without being told, and
> 	this option was a way to tell it to.
> 
> but this would lead to littering the documentation with too much 
> historical information in the long run.  I dunno.  I am inclined to 
> favor the removal as your patch did, but somebody else may have clever 
> ideas.

> > +	if (!strcmp(var, "gc.pruneexpire")) {
> > +		if (!value)
> > +			return config_error_nonbool(var);
> > +		if (strcmp(value, "now") &&
> > +				approxidate(value) - approxidate("now") >= 0)
> > +			return error("Invalid gc.pruneExpire: '%s'", value);
> 
> Yuck; approxidate() returns ulong.  Can subtracting a ulong from another
> ever go negative?
> 
> Besides, because there is no guarantee of the order of evaluation between
> these two approxidate() calls, you may get +1 or -1 on the second boundary.
> 
> I think the reason why you did not catch it in your test is because your
> tests are half complete; they test only what you wanted to catch
> (misconfigured case) and do not test the other half (properly working
> case).