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Re: [PATCH] Infrastructure to exclude comparing lines

From: Daniel Shahaf <d.s_at_daniel.shahaf.name>
Date: Wed, 22 Sep 2010 20:04:58 +0200

Ramkumar Ramachandra wrote on Wed, Sep 22, 2010 at 22:24:10 +0530:
> Hi Daniel,
>
> Daniel Shahaf writes:
> > Ramkumar Ramachandra wrote on Mon, Sep 20, 2010 at 09:39:57 +0530:
> > > Daniel Shahaf writes:
> > > > * ignore Prop-delta... why?
> > >
> > > This is because svnrdump outputs "Prop-delta: true" everytime, whether
> > > it's really a delta or a delta from /dev/null. This is quite harmless,
> > > and the logic for omitting it when it's a delta from /dev/null can be
> > > fairly non-trivial and unnecessary. Again, svnadmin dump does it
> > > "right".
> >
> > Okay, but if the Prop-delta: header is generated by one but not by the
> > other, then the rest of the dump'd props hash should be different too.
>
> Huh? Why?
>
> > i.e., if the tests ignore difference in the Prop-delta: header, they
> > should also be finding more differences later in the props hash --- and
> > should "somehow" be ignoring those correctly...
>
> Ok, I think you've misunderstood this. Both of them DO dump the exact
> same properties. Think of the Prop-delta header as just an extra
> cosmetic line. In dumpfile v3, everything is a delta against the
> previous revision including props.

Did you mean: s/In dumpfile v3/In 'svnadmin dump --deltas'/ ?

IOW, the dumpfile format version doesn't enforce that, but svnadmin
never produces non-delta'd props when it dumps as v3 --- right?

(I think/assume that you can take any v2 dumpfile and just change the
header from "format: 2" to "format: 3" --- without making any other
changes --- and still have the result a valid dumpfile...)

> When the Prop-delta header is
> absent, it doesn't mean that the full props are being listed- it just
> means that the file or directory didn't exist in a previous
> revision. For a file or directory that didn't exist in a previous
> revision-
>
> * [Prop-delta missing] is a cosmetic way of saying: "Here's a new file
> or directory along with it's properties."
> * Prop-delta: true is a cosmetic way of saying: "Here's a file or
> directory. If it's new, the delta is against nothing. If it's old,
> the delta is against a previous version. Check it for yourself-
> information about whether the file or directory is new is already
> present in the dumpfile."
>

In other words, the only case where svnrdump and svnadmin disagree on
the presence of the "Prop-delta:" header is in the case of
added-without-history files; and in that case, svnrdump prints it and
svnadmin doesn't, and this doesn't matter since interpreting the dumped
hash as a delta or as an absolute full properties list gives the same
result...

Right?

Thanks for clarifying,

Daniel

P.S. Doesn't the "Node-action:" header allow you to distinguish whether
it's a newly-added file or not, and thus be able to generate Prop-delta:
only in the cases that svnadmin generates it?
Received on 2010-09-22 20:07:35 CEST

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