Unable to follow another way based on a new node

[1ec5]

The “follow” operation added in #8671 only works if the current way is connected to enough consecutive saved nodes on another way, but if one or more of those nodes is being added as part of the same changeset, the needs_more_initial_nodes message appears. (“This line can't follow a way because it isn't connected to enough consecutive points along a way.”)

To reproduce, draw a line with two points:

then draw another line that connects to it at two new points in the middle:

Finally, press F to follow the original line.

I think this is because of these hasEntity() checks:

iD/modules/behavior/draw_way.js

Line 443 in 7699034

if (!lastNodeId || !secondLastNodeId || !startGraph.hasEntity(lastNodeId) || !startGraph.hasEntity(secondLastNodeId)) {