[TRAC-2518] Bug while using measuring tool.
Look at that material:
Draw segments "Biene" -> "Trinkstelle" and "Trinkstelle" -> "Stock" and then get the lenght with the measureing tool. Just click with the "cm" tool on the segments. The values of the lenght is shown ... as wanted ... but an other distance is shown, too. The distance between the segments!?