lines with markers move when flipping

[Désarménien]

When you add a starting arrow of type #Arrow2Lstart to a horizontal line and then flip the line vertically, it moves down. If you do it with a vertical line, it moves left when flipping horizontally.

It's not true with #Arrow1Lstart and some others, but happens with custom markers.

Tweaking the path of markers (d="...") in markers.svg strongly influences this anomaly.

That means, more generally, that the presence of markers may influence the lines position, which, in my opinion, is really not an expected behaviour and probably hides a bigger problem in internally bounding objects with markers.

This happens identically on Mac OS X El Capitan, Inscape versions 0.91 and 0.92.0 and on Linux Ubuntu 14.04 LTS, Inkscape version 0.48.4r9939.

Attaching a sample file to demonstrate the problem : select the line and click vertical flipping button repeatedly : the line moves down from the horizontal guide (sample using #Arrow2Lstart)

Hope this helps.

François