A directory with only one subdirectory ("plv" in the screenshots) is compared to an empty directory in a trunk directory (with subdirectory comparison, and with the filter for source code and subversion...).
The subdirectory "plv" is effectively compared with the ".svn" !! (see screenshot page 3).
Test is made renaming the "plv" directory (with uppercase, with more chars, with another text ...) but the bug always appears.
Only the case of adding another directory make the bug disappear (screenshot page 2).
Using Winmerge 22.214.171.124 (portable version on Windows) (see screenshot page 1).