Comment 35 for bug 170378

I've tried with a group of 6 lines with the transform attribute scale(0.2,0.2) and stroke width 12 px. There is also a line outside the group (no transform) with stroke width 2.4 px (actually 2.4000001 px).
All lines show a 3 px width in the Fill and Stroke dialog (because there is a parent transform scale (1.25, 1.25)).

If I select the outside line and "Select Same Fill and Stroke", nothing else is selected.
If I enter the group, select one line and "Select Same Fill and Stroke", all the lines in the group _and_ the external line are selected.
If I ungroup the group with the Optimized transformation option, all its lines get 2.4000001 px width, and this explains the rounding discrepancies.
If I ungroup the group with the Preserved transformation option, all lines keep their transform attribute and stroke width but all always get selected (toghether with the one without the transform attribute).

So the function seems to work, it just doesn't (correctly) enter groups from the outside.
It takes into considerations all transforms, as the Fill and Stroke dialog does when exposing the "visual" width: to be honest, I hadn't noticed this before, so my speculations on parents' attributes in the last post were simply wrong (they were based on the XML Find and Replace experience).