[visual-qa] Ctrl-right-click delete on CIRCULARSTRING leaves a phantom point

[grootstebozewolf]

Witness (RC3)

Move/add/delete vertex tool. Ctrl-right-click a control on a CIRCULARSTRING (or a GEOMETRYCOLLECTION of them) does delete the vertex, but a phantom point stays on the canvas.

Screenshot: Screenshot 2026-08-22 140117.png.

Why

1. Even leftover. Insert ([visual-qa] EditVertex right-click add vertex on CIRCULARSTRING makes even control count #82 / PR fix: EditVertex right-click add on CIRCULARSTRING keeps odd control count #83) adds +2 so the control count stays odd. Delete still removes one coordinate (GeometryVertexDeleter). A 5-control CS becomes 4. The renderer walks triples (0,1,2), (2,3,4), …; the even leftover is drawn as a dangling vertex / chord that is not an arc — the phantom.
2. XOR indicator. EditVertexTool.mouseClicked (right-click insert/delete) never clearIndicator(). A prior left-press draws the rubber-band circle in XOR; right-click mouseReleased returns without clearing it, so the circle stays at the deleted vertex.

Not HotPixel. Same tool path as #82, inverse operation.

Expected

• Ctrl-right-click delete on a CircularString removes two controls (the vertex and its paired mid), count stays odd and ≥ 3.
• 3-control CS refuses delete (would drop below a single arc).
• No leftover vertex in the WKT; no XOR circle after the click.
• GeometryCollection wrapper kept.

Do not close without UX SIGN.

[grootstebozewolf]

RC3 screenshot matches even leftover: CIRCULARSTRING (…, 584 294) is 6 controls. The isolated square is the dangling 6th point, not HotPixel.

Fix on PR (ctrl-right-click delete now −2 so the count stays odd; XOR indicator cleared). Do not close without UX SIGN. RC3 remains HOLD.

[grootstebozewolf]

PR #98: #98

[grootstebozewolf]

SIGN (UX, 22 Aug 2026)

UX SIGN on RC4. Last new RC4 case.

• https://github.com/grootstebozewolf/jts/releases/tag/RC4
• commit 65d02ef9 on SFA/SQL-MM curve awareness: Curve rename, arc-aware operations, OverlayNGCurve ratchet (#1195 RGR series) #7
• JTSTestBuilder-RC4.jar SHA-256 be1e56b68aab8fd3de2411ad7fd5968add415fc6253eef392ee1ab8f95f51d04

UX HOLD on the RC4 mint as a whole still stands. #92 gesture parked (HOLD). #114 is a later find, not in this mint. Do not flip Notion. Ticket stays OPEN until PO says close.