Version Control with Subversion

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

Copying Changes Between Branches

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If you want changes applied somewhere else, you need to say so explicitly. For exam-

ple, if you’re sitting in the parent directory of your working copy, you have to spec-

ify the target directory to receive the changes:

$ svn merge -r 343:344 http://svn.example.com/repos/calc/trunk my-calc-branch

U my-calc-branch/integer.c

Best Practices for Merging

Merging changes sounds simple enough, but in practice it can become a headache.

The problem is that if you repeatedly merge changes from one branch to another,

you might accidentally merge the same change twice. When this happens, some-

times things will work fine. When patching a file, Subversion typically notices if the

file already has the change, and does nothing. But if the already existing change has

been modified in any way, you’ll get a conflict.

Ideally, your version control system should prevent the double application of

changes to a branch. It should automatically remember which changes a branch has

already received, and be able to list them for you. It should use this information to

help automate merges as much as possible.

Unfortunately, Subversion is not such a system. Like CVS, Subversion 1.0 does not

yet record any information about merge operations. When you commit local modifi-

cations, ...