Fix issue #3486, "attempt to add tree conflict that already exists", again. Hopefully this is the last time we'll need to deal with this.
Fix issue #3486, "attempt to add tree conflict that already exists", again.
Hopefully this is the last time we'll need to deal with this.

* subversion/libsvn_client/merge.c
  (tree_conflict): Always check for an existing tree conflict before
   attempting to record a new one. If one already exists, do nothing.
   Multiple attempts to flag a conflict can happen when a merge performs
   multiple editor drives, because of a gap in the range of eligible
   revisions. There is no point in aborting the entire merge because of this.
   The user will have to sort out the conflict anyway.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1058269 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion