How do I get SVN to realize a binary file's changed if the filesize is fixed

Question

I'm working with a program that writes data to fixed-size binary files that I store in a subversion archive.

The problem, however, is SVN (both the command-line client and TortiseSVN) thinks that since the size of the file didn't change, the file itself didn't change and it shouldn't commit it.

Is there a way to change what diffing method is used, or do I have to resort to hacks such as adding a dummy property to the files?

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EDIT: Turns out the solution wasn't becuase of the file-size thing. I just automatically assumed that would be the case, since most nieve diffing altorithims do this all the time. ^{[weasel words]}

Answer 1

See here for a description on how SVN determines whether a file is modified or not.