svn merge tree conflict: unable to determine the conflicting local changes

Hi,

I'm trying to understand a tree conflict problem during merge. After the merge from an import branch to trunk the client states
"Tree conflict on 'upload.bat'
> local file edit, incoming file delete upon merge"

Normally I understand tree conflicts and generally know how to solve them. But I am not able to see which changes have been done to the file that are causing the conflict. There simply are none. svn log on trunk only shows two revisions:
- adding the file in the initial import on the branch
- copy to trunk

So I'm not sure whether I'm doing something wrong or if this is a bug in subversion.

I was able to dump and load the relevant parts of the repo and put it to a public server. The error is still reproducible. The repo can be found at
svn://kfpc.de/Test/trunk/QtSrc

The repo is still quit large. But for demonstration only trunk/QtSrc/qtwebengine/src/3rdparty/chromium/buildtools/win/ is needed.
Merging branches/b015001/QtSrc/qtwebengine/src/3rdparty/chromium/buildtools/win/ into trunk will result in the tree conflict on 'upload.bat'.

There are five more tree conflicts with deleted directories during a complete merge which are of the same category. There have never been changes to these directories or to file/sub-folders inside the directory since the initial import.
Unfortunately there are more than 50.000 files/directories involved in the whole action. So it is not that simple to get an overview.

I know that I could simply solve the conflicts as I know that the changes from the branch are what I want. But I'd really like to understand the issue.

The original server is using subversion version 1.8.10 (VisualSVN Server Standard Edition 3.2.1). I tried the merge under Linux (command line client version 1.8.13) and Windows (TortoiseSVN 1.8.11, includes subversion 1.8.13).

--
Christoph
Sigma Surface Science GmbH, Idsteiner Str. 78, 65232 Taunusstein. Amtsgericht Wiesbaden, HRB 27422. Geschäftsführer: Norbert Nold