Re: [Axiom-developer] GIT

[Gabriel Dos Reis]

"Page, Bill" <address@hidden> writes:

| Gaby,
| 
| Since Tim has agreed to what I proposed below and no one
| else has disagreed, I would like to plan for this but I
| would appreciate your opinion first on how best to do it
| without screwing up the SVN repository to badly. Specfically
| what we would be trying to do is to replace the existing
| /trunk on SourceForge with one derived via Tailor from Tim's
| new axiom--silver--1 repository. And to set up a cronjob on
| axiom-developer.org to automatically update it each night.

I whole-heartily welcome Tim's agreement.

| One way to do this would be to first of all delete /trunk
| from the repository and rebuild it from the current contents
| of axiom--silver--1, but given the little I understand about
| how SVN works, I am concerned that using svnadmin to delete
| /trunk might have serious consequences for any branch cloned
| from /trunk (such as build-improvements). Am I wrong about
| that?

I don't know all the gory details of SVN implementation, but my
understanding is since SVN works by changeset, any change you make to
the repository is recorded as a global change with a given revision
number (even those branches that are not directly affected see the
change in the revision number).  Consequently, if you "delete" trunk
-- but not the metadata -- and replace it with a new copy, then
technically SVN would record all those changes, and the diff between
the branches should be able to compute correctly the change set.  This
assumes the "delete-and-replace" operation is trouble-free. 

This is obvious, but please make a backup of the repo before you start :-)

Please run my theory my "the SVN guy at Google" :-)

| Is deleteing and re-creating /trunk a safe and sensible
| thing to do?

It certainly is a "direct" way to approach the issue.  If my theory
above is correct, we should be fine.  I call it "theory" because I
have not done this typeo of manip with CVN before.

| I suppose a safer (but more complex) thing to do would be
| to try to compute a changeset that would modify /trunk in
| just the right way to make it's current state (but not it's
| history!) the same as axiom--silver--1. I could probably do
| that by creating a completely separate /trunk2 and then
| appropriately diff /trunk and /trunk2 - though I will have
| to learn a little more about SVN to do this properly, I
| think.

yes, that is another way; one that requires patience :-)

-- Gaby