CornerData seems to not update correctly during mutation

Start at mesh->insertVertexAlongEdge(edge) and trace how CornerData associated with the affected halfedges and corners is transferred during the mutation. Reproduce the two-rectangle case described in the issue, checking which corner loses its UV data; done means the mutation preserves the expected CornerData and the non-manifold question is explicitly addressed.

Hi,

First of all, great work on this library !

I'm trying to do some simple mutation, like adding a vertex along an edge. I have this geometry in the image below which could be seen as 2 rectangles merged together, and I have different CornerData (let's call them UVs) for each corner of the rectangles.

When I try to add a vertex along the shared edge, it seems that some CornerData are lost (showed with the ?).

Is this normal behavior ? How could I change this besides copying the CornerData before the mutation and rewrite them later ?

Right now I do :

//Store UVs
Vector2 previousUVF1 = uvData[edge.halfedge().corner()];

//Insert new vertex, and get the halfedge in the center point, then rewrite UVs
auto newhe = mesh->insertVertexAlongEdge(edge);
uvData[newhe.prevOrbitFace().corner()] = previousUVF1;

(And this is not related to this issue, but will mutation like adding a vertex along an edge be available for non manifold meshes ?)

Thanks again for you work.

-Edit : after further investigation, it seems that only one corner lose his data. Update the image to reflect that