Re: [Monotone-devel] Re: Bug in CRLF conversions

[Richard Levitte - VMS Whacker]

In message <address@hidden> on Wed, 1 Feb 2006 07:24:22 -0500, Ethan Blanton 
<address@hidden> said:

eblanton> Richard Levitte - VMS Whacker spake unto us the following wisdom:
eblanton> > mlh> On Tue, Jan 31, 2006 at 07:50:51AM -0500, Yury Polyanskiy 
wrote:
eblanton> > mlh> > Again: solution is trivial. "Transform what I ask
eblanton> > mlh> > you to (LF->CRLF and back) and don't mess with
eblanton> > mlh> > anything special (like CR->CRLF etc)."
eblanton> > mlh> 
eblanton> > mlh> The other nice thing about this is that it's
eblanton> > mlh> perfectly reversible, even for 'binary' files.
eblanton> > 
eblanton> > Provided CRLF would be the internal normal line end form.
eblanton> > It is currently not, so the real transformation on commit
eblanton> > would be CRLF->LF.  Then, when checking out, the reverse
eblanton> > transformation would occur, LF->CRLF.  Here's where the
eblanton> > fun start, what do you think happens if said binary had an
eblanton> > embedded LF somewhere to begin with?
eblanton> 
eblanton> This should still be reversible.  You are correct that the
eblanton> checked-out binary will be corrupted, but it will not show
eblanton> up as changed, and nor would it be corrupted on checkin.

Eh?  I did not follow that.  Why would it not show up as changed?
Compared to what?  And in what way does a binary not get corrupted on
checkin when a LF->CRLF transformation is made?

eblanton> The working space corruption is a problem with whether or
eblanton> not the file was marked binary, which is orthogonal.

Really?  If we treat binaries as "DO NOT TRANSFORM IN ANY WAY", would
you still say there's a corruption problem?  How?

eblanton> I don't understand what the pushback is here ... Yury seems
eblanton> to be suggesting something which is clearly correct to me,
eblanton> and it's being conflated with a separate problem (marking
eblanton> files as binary) and dismissed.

The suggestion I see is that the transformation he suggests is
reversible.  I do not see that, so either the proposal is incomplete
(for me) and needs expansion, or we understand "reversible"
differently, or the suggestion has flaws (which is what it looks to me
so far).  So, if Yury could expand, perhaps by saying (and possibly
repeating, my appologies) what transformation should be done on
checkin, on checkout, and how binary files are safe in that kind of
transformation, I will most certainly be able to follow.

Cheers,
Richard

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-- 
Richard Levitte                         address@hidden
                                        http://richard.levitte.org/

"When I became a man I put away childish things, including
 the fear of childishness and the desire to be very grown up."
                                                -- C.S. Lewis