Andrew,

Regarding: Forum topic 12045
Trying to replicate the problem reported by user 'Leno'.

With a selection and for an action that expects a coordinate input,
with snap mode selection (SK)
there are no snapping points displayed to select from.

Expecting 10 reference markers in color #0040c8 by default.

Changes were made around Jun 5, 2026
Snap/SnapSelectionCenter → Snap/SnapSelection

Also troubled by the associated note in EAction Line 287 Commit 4d3a6e5

The note states that the zoom state is set to auto.
But it is the document interface snap mode that is (re-)set to auto on resuming.

Regards,
CVH

For a point coinciding with the center, getAngleTo() at line 788 returns zero by default.
For an arc starting at, ending at or spanning over orientation zero
(verified and not excluded by line 789-791)
the method returns a defined point on the arc at zero rads.

Analog to RCircle::getVectorTo there are infinite solutions and thus none well defined.

The RCircle method excludes a point at the center and returns an invalid RVector.
… However:
Comparing the SquaredMagnitude() with 1e-18 is fundamentally incorrect (FS#2741)
Correctly squaring both sides of (|d - v| < tol) results in: ((d - v)² < tol²)
And this expands to: (d² - 2dv + v² < tol²) where one still needs to know the magnitude.

… Additionally:
getAngleTo() returns zero by default when the two points are 1e-6 units or less apart.
A factor thousand times larger than RS.PointTolerance.
This can still result in a defined point on the arc at zero rads for
points at a distance between 1e-9 to 1e-6 from the center.

As like all getVectorTo() methods it is a key resource.
RArc::getClosestPointOnShape() can for example return a false solution.

Fixing this may for example break InfoDistanceEP.prototype.pickCoordinate or RSnapPerpendicular::snapEntity …
… Only if you manage to indicate really near the center of an arbitrary arc.

Then RSnapPerpendicular::snapEntity has no solution for a circle and its center.
But it has a solution at zero rads for an arc.

Regards,
CVH

Draw arc from 3 points: 5,5 - 15,20 - 25,0

Break out arc segment at 4.2,8.95

The tool can report “Object selected: nnn” when selecting an offending entity while nothing seems to be selected.
The search for the offending entity can be simplified by also reporting its Block name.

    if (isEntity(obj)) {
        di.selectEntity(obj.getId());
        EAction.handleUserMessage(qsTr("Object selected:") + " " + obj.getId() + " (" + obj.getBlockName() + ")");
    }

The object ID nnn is of no use for a common user.

Automatically switching to the Block in question is perhaps even better.

In the referred topic the user explains how to find and delete the entity.
It won't be saved thus saving and reopening is then the more simplier solution.

Offending is for example an ellipse with a negative ratio.
Not automatically fixed by correctMajorMinor().
But easily fixed when selected (in the current Block).

Regards,
CVH