svn - Subversion and shared files across repositories/projects?

Question

I am migrating a client's SourceSafe repository (3 projects) to SVN and two of the projects share source files. (These projects are separate products - with different names and release versions, etc)

Has SVN resolved this shortcoming? How do people generally handle this scenario?

Of the options I know about/can think of

• Use the external or extern or whatever for SVN. I hear this is not a good option for various reasons

• Create a new project (maybe called shared) that contains the source. The problem with this is that we still have to get that code (it is not a library) and import it into the project somehow. It can be shown to be the same problem as the one above and it introduces the overhead of an additional product/project.

• Just check in the files in both repositories and cross-update them. This requires developers to know about the sharing and to remember to check in. I suppose I could write a script that checks all known shared files and updates them when needed.

• Have one repository for the two projects that share. This leaves me with the problem having to create a top level project/repository that contains the two and it is a problem for labeling. I do not really want to label the top pseudo project. (the tags, trunk and branch things are not exactly where I would want them.)

I will probably go with the last option.

Any other comments?

Answer 1

I don't know what exactly you heard about svn:externals, but I think that's what you should use here. You can even specify your external to point to a stable branch or release tag of you shared source, or even point to two different tags from the two other projects that use it (you might need this if you fix some bug in the shared code ASAP for project A, but you don't have enough time to test it fully with project B).

The worst thing you could do is your option 3 (cross-updating two versions of the same files).