Vincent Lefevre wrote: > Hi, > > The description of the Peg Revision Algorithm on > > http://svnbook.red-bean.com/nightly/en/svn-book.html#svn.advanced.pegrevs > > is incomplete. It doesn't say how <item> is identified when it is > relative to a working copy. This is particularly important when > the directory in question has been renamed/moved in the past and > PEG-REV is a revision before the rename. > > IMHO, it should follow the directory history, but this doesn't seem > to be what happens.
I think you've missed a key assumption of the peg-rev algorithm. (And perhaps this is the true failure of my peg-rev description in the book -- I'm willing to accept that possibility.) The (path, peg-rev) informational pair is really the primary input to the algorithm, and is expected to represent a point in the history of the object of interest *that you already know*. This is why Subversion defaults to using 'BASE' for the peg-rev on working copy operations -- your working copy reflects paths at revisions that they are known to exist at. It's the operational revision that you then supply or tweak to operate on some older version of that thing. I think you're describing the situation where you have a working copy of, say, ^/branches/my-branch, copied from ^/trunk in r100. In that working copy, you run 'svn info some/deep/fil...@50'. At that moment, you are asserting your belief that /branches/my-branch/some/deep/file.c exists at revision 50. You'd be wrong, of course. Instead, you should tell Subversion only what you know, and allow it to help you figure out what you may not. By saying 'svn info some/deep/file...@base] -r50' (the @BASE bit is the default, but you can specify it explicitly if you wish), you tell Subversion "I know that some/deep/file.c exists as it is represented in my working copy, but I'm not sure where it lived back in r50 -- go find that place for me and then perform the operation I requested." Have I understood your concern? Is there something I can do to make that book section more understandable? -- C. Michael Pilato <cmpil...@collab.net> CollabNet <> www.collab.net <> Distributed Development On Demand
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