Area Drawing has issues using way segments to start or finish the area shape.

[Bonkles]

If you start an area drawing gesture by clicking on an existing way segment, it SHOULD stitch a new node to the segment and then show you the polygon drawn from that new node to the mouse pointer. Instead, you get a single new node and a stack trace.

area_draw_from_way_segment_doesnt_work.mov

Stack trace is generated as soon as the user clicks to add the second vertex to the area:

Uncaught TypeError TypeError: Cannot read properties of null (reading 'id')
    at _clickLoc (/Users/clarkben/working/RapiD/modules/modes/ModeDrawArea.js:264:52)
    at _click (/Users/clarkben/working/RapiD/modules/modes/ModeDrawArea.js:226:10)
    at emit (/Users/clarkben/working/RapiD/node_modules/eventemitter3/index.js:181:35)
    at _doClick (/Users/clarkben/working/RapiD/modules/behaviors/BehaviorDraw.js:303:10)
    at _pointerup (/Users/clarkben/working/RapiD/modules/behaviors/BehaviorDraw.js:213:12)
    at emit (/Users/clarkben/working/RapiD/node_modules/eventemitter3/index.js:181:35)
    at _pointerup (/Users/clarkben/working/RapiD/modules/pixi/PixiEvents.js:242:10)
    at notifyListeners (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:1313:26)
    at notifyTarget (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:549:18)
    at propagate (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:325:14)
    at dispatchEvent (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:240:14)
    at mapPointerUp (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:830:14)
    at mapEvent (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventBoundary.ts:261:28)
    at onPointerUp (/Users/clarkben/working/RapiD/node_modules/@pixi/events/src/EventSystem.ts:290:31)
_clickLoc @ /Users/clarkben/working/RapiD/modules/modes/ModeDrawArea.js:264:52

[Bonkles]

Fixed in bd437d95c.

Here's a preview of the now-working functionality:

area_drawing_with_way_segments_works.mov