In DIFFMF I found it supports Ctrl+H to hide the current file --- I really nice hidden feature!
But, hit Ctrl+H two times and the other tree is completely hidden - very bad.
The problem seems to be that _TreeGetSelectionIndices() returns the same index as the one previously hidden. I think that the tree is left with the selection on the item just hidden.
So, do a MFDIFF.
Select a file on the left.
Ctrl+H -- its hidden.
Ctrl+H again: The entire right tree is hidden.
On the first Ctrl+H, _TreeGetSelectionIndices() returns "x"
On the second Ctrl+H, _TreeGetSelectionIndices() returns "x" again
This confuses HideLinesInBothTrees() because _TreeCurLinNumber() returns 0, but the current line number is queried from the left tree but only set on the right.
