Irrevocably locked working copy after svn delete

Dear Subversion team,

I want to file a bug report affecting the most recent released version 1.8.5.
Whenever I issue asvn delete on a versioned file on which the subversion client does not have any access rights, the working copy is irrevocably locked until the file is deleted manually by other means.

Environment:

      * Intel i7 2.6Ghz cpu

      * 8Gb RAM

      * Windows 7 x64 Professional

      * Subversion 1.8.5 x86 (downloaded from Collabnet)

Scenario:

1) svnadmin create testrepo
2) set anonymous access to write
3) svnserve -d --listen-host=localhost --listen-port=4444 --root=testrepo
4) svn cosvn://localhost:4444/ wc
5) cd wc
6) echo Hello Subversion! > testfile
7) svn add testfile
8) svn commit -m "initial commit"
9) now remove any read/write/execution rights on testfile for user that executes subversion client
10) svn delete testfile (fails as expected)
> svn: E155009: Failed to run the WC DB work queue associated with
> 'G:\svnlog\wc\test', work item 4 (file-remove test) svn: E720005:
> Can't set file 'G:\svnlog\wc\testfile' read-write: Zugriff verweigert

11) now any subsequent working copy operation (e.g. svn status) fails with
> svn: E155037: Previous operation has not finished; run 'cleanup' if it
> was interrupted

12) cleanup fails with
> svn: E155009: Failed to run the WC DB work queue associated with 'G:\svnlog\wc', work item 4 (file-remove test)
> svn: E720005: Can't set file 'G:\svnlog\wc\testfile' read-write: Zugriff verweigert

I did a similar test trying to commit modifications on a modified versioned file which cannot be accessed by subversion client either.
The commit fails as expected but the working copy remains alive, i.e. other svn operations are still possible.

I hope you will be able to reproduce the problem and may assist me in solving it.
Many thanks in advance.

Greets
Alexander Lüders

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