Questions around hybrid file locking

Hi all 

I work on tdf#106942, the code is here sfx2/source/doc/docfile.cxx:1151

I don't understand why skip all errors with "UseDocumentSystemFileLocking" docfile.cxx:1175, 
anybody got any recollection why that is? 

But when "UseDocumentSystemFileLocking" is false (well currently it's always true) and the error is 
IOErrorCode_INVALID_PARAMETER, a message box - that says something like 'can't lock, b/c lockfile 
cannot be created'

I think this message is never appears, because the error “Invalid Parameters” is implausible, too.

Here's how I'd plan to solve this:: 
When the error with "no access &| no space" came, then using the above message (need only improve 
the second message-line), and set the document to read only, and remove the empty lock-file. 

Anybody got any better ideas?



best 
Juergen