hgmerge: do not use file with markers in tools merging themselves
This time I forgot about a crucial part of the logic change.
The patch makes kdiff3 and tkdiff useful again.
abort: repository a not found!
255
requesting all changes
abort: error: Connection refused
255
abort: repository a not found!
255
abort: destination '../a' already exists
1
abort: repository a not found!
255
abort: destination 'q' already exists