Interpreting negative SEQ length in show-diff

[cedricblais]

Hello,

I have found that some of the lengths listed for SEQ features in the show-diff outputs are negative. Here is an example:

scaffold_8 DUP 814843 816150 1308
scaffold_8 GAP 843515 844365 851 724 127
scaffold_8 SEQ 851807 851663 -143 scaffold_9 scaffold_22
scaffold_8 BRK 851837 854239 2403
scaffold_8 DUP 854240 854483 244

When I look at the corresponding coordinates in the out.mcoords file, it looks like the region partially corresponds to an alignment, not a gap:

816030 843514 659818 632359 27485 27460 83.81 1497812 1483417 1.84 1.85 scaffold_8 scaffold_9
844366 851806 631634 624353 7441 7282 86.67 1497812 1483417 0.50 0.49 scaffold_8 scaffold_9
851664 851836 766831 766665 173 167 89.60 1497812 1179946 0.01 0.01 scaffold_8 scaffold_22

On the manual there is some discussion of how to interpret negative gap-diff, but I found no such discussion of negative SEQ length. I was wondering how these results should be interpreted?

Thank you!