AW: Auto Upgrade Behavior

Hi,

Von: Stefan Sperling [mailto:stsp_at_apache.org]
> On Fri, Aug 24, 2012 at 05:21:09PM -0400, Paul Burba wrote:
> > Currently trunk tries to auto-upgrade the WC pretty much every chance
> > it gets, even when the cwd is an unversioned directory within a WC.
> > I've been wondering if this is really such a good idea -- it's been
> > quite noticeable, in an annoying way, while working on the
> > inheritable-props branch.
> >
> > What happens is this:
> >
> > 1) I check out the iprops branch with a Subversion 1.7.6 client (WC
> > format 29) to C:\SVN\src-trunk-2)
> >
> > 2) I build the iprops branch, which is using WC format 30.
> >
> > 3) From the root of my iprop WC I run the test suite. The first
> > checkout done as part of the test auto-upgrades the WC rooted at
> > C:\SVN\src-trunk-2 to format 30, even though the cwd of the checkout
> > is an unversioned directory
> > (C:\SVN\src-trunk-2\Debug\subversion\tests\cmdline) and the checkout
> > target is below that
> > (C:\SVN\src-trunk-2\Debug\subversion\tests\cmdline\svn-test-
> work\working_copies\basic_tests-1).
> >
> > Pretty much any command with an unversioned directory under an older
> > format WC root will attempt to upgrade that root.
> >
> > Probably not a huge problem for anyone who is not a Subversion
> > developer, but it's something we might want to keep in mind as we bump
> > the WC format in the future.
>
> Can't we just disable auto-upgrade and add a config option to enable it
> for those who really want it?

I'm not sure whether a disabled auto-upgrade will improve Pauls situation here, it will most likely cause the "checkout" operation in the nested working copy to fail.

That said, for CoDeSys SVN we cannot perform automatic upgrades. The reason is that we guarantee that projects can be still opened with older CoDeSys versions as long as the user did not explicitly allow the format to be upgraded. (This is part of a rather strict backwards compatibility strategy, which even includes a guarantee of providing bit-identical compilations including bugs when the user configures an older compiler version.) On the other hand, we're using our own metadata for that check even before the svn libraries are allowed to touch the working copy, so we can cope with whatever SVN implements here. :-)

Best regards

Markus Schaber

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