Fix issue #4859 "Merge removing a folder with non-inheritable mergeinfo -> E155023: can't set properties: invalid status for updating properties".
The code was attempting to set mergeinfo on a path that is being deleted by the merge. This happened only in certain unusual cases such as when deleting a folder that had non-inheritable mergeinfo and had children.
This patch fixes the problem by removing the 'children_with_mergeinfo' entries for sub-paths of a deleted folder.
* subversion/libsvn_client/merge.c (merge_cmd_baton_t): Allow modifying 'children_with_mergeinfo'. (record_update_delete): Remove from 'children_with_mergeinfo' all paths in the subtree.
* subversion/tests/cmdline/merge_tests.py (merge_deleted_folder_with_mergeinfo): Remove 'XFail'. (merge_deleted_folder_with_mergeinfo_2): New test. (test_list): Add the new test.