Segfault when upgrading

Hi,

I've now analyzed the fifth crash report for TSVN that shows a segfault
when upgrading a working copy. The crash happens here:

libsvn_wc\upgrade.c, line 1111

         info = apr_hash_get(*text_bases_info, versioned_file_name,
                             APR_HASH_KEY_STRING);

with 'versioned_file_name' being NULL.
(ok, the crash is in the hash function in the apr lib, but it crashes
because the key string is NULL).

Problem is I have no idea why that would be NULL, it gets set a few
lines above by the 'remove_suffix()' function which only returns NULL if
either the filename is too short or the extension doesn't match - which
I can't see why this would ever happen.

Anyone got any ideas?
I've asked those who sent those reports, but they have no idea what's
different about their working copies. All of them had several working
copies, and the crash happens only with one or maybe two of them, but
not all of the working copies they upgrade.

Stefan

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