Bug in ULevel::FixupActorFolders.

There is a potential bug in ULevel::FixupActorFolders() in the FixDuplicateFolders section:

Suppose you have a folder hierarchy that looks like this:

• A
  • B(1)
  • B(2)
    • C(1)
  • B(3)
    • C(2)

where the letters are the names of the folders and the numbers are used to distinguish between folders with duplicate names. All the folder paths are:

• A
• A/B(1)
• A/B(2)
• A/B(2)/C(1)
• A/B(3)
• A/B(3)/C(2)

All but the first are duplicates. There will be two sets of folders in PathToFolders:

• A/B(1)
• A/B(2)
• A/B(3)

and

• A/B(2)/C(1)
• A/B(3)/C(2)

SortedDuplicatePaths will contain:

• A/B
• A/B/C

After the first pass through the loop starting at line 3043 of Level.cpp, FoldersToKeep will contain:

• A/B(1)

and FoldersToDelete will contain:

• A/B(2)
• A/B(3)

The problem happens in the second pass through the loop during the search for FolderToKeep. The parent of A/B(2)/C(1) is A/B(2) and the parent of A/B(3)/C(2) is A/B(3). Both are to be deleted. As a result, FolderToKeep is not set and the check() on line 3058 fails.

• Create a WP Map
• Create Folder A
• Create SubFolder B (under A)
• Save/Close WP map
• Shelve and delete from disk SubFolder B package file
• Reopen WP map
• Create SubFolder B (under A)
• Create SubFolder C (under B)
• Save/Close WP map
• Shelve and delete from disk SubFolder B and SubFolder C package files
• Reopen WP map
• Create SubFolder B (under A)
• Create SubFolder C (under B)
• Save/Close WP map
• Unshelve all deleted files
• Reopen WP map