Comment 3 for bug 1673924

this bug has two components, both of which have been reported previously:

1) Failure to use outset amount set in preferences
This part was fixed in rev 15610, http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/15610
see Bug 1542093 - Inset/outset step size change with page units

2) Distortion of original shape (e.g. rectangle to curved blob).
This appears to be a duplicate of these two previous reports:
Bug 668341 - Simplify path does not work properly
Bug 616469 - "Outset/inset path" act erratically if input path is small

All these reports share the fact that they use the routine Path::Simplify in the file PathSimplify.cpp, which is capable of distorting the shape of an object, particularly if the size is not large relative to the Preference value for Preferences->Steps->"Inset/Outset".