SVN external file workaround

I am using SVN. I want开发者_JAVA百科 to have external file in my working copy. I have a folder with files from my repository. And I also want to have one file from external third party repository.

SVN externals can be used for folders only.

Since version 1.6 externals for files are supported, but for the files in the same repository only.

How to workaround this limitation? Which approaches, practices, tricks whatsoever could be used for this situation?

svn:externals can be used for files since Subversion 1.6:

If the URL in a svn:externals description refers to a file, it will be added into the working copy as a versioned item.

note the differences to directoy externals [1, 2].

Can you place that one file in it's own directory in the other repository, then use svn:externals to the folder with just the file you are interested in?

RepoA
    - ComponentDir
        - ComponentA

RepoB
    - ComponentDir (svn:externals to RepoA/ComponentDir)
        - ComponentA

In reality, how often do you expect this component to change? Why not just commit it independently and not worry about an external feature at all?