Technically a regression in [0] however even before this commit
there where no check to prevent an intersection being used which
is far outside triangle the vertex is sliding towards.
Resolve by only using the line-line intersection if the intersection
points lie within a conical region defined by the edge pair the user
is sliding towards (see code-comment for details).
Ref !144418
[0]: 49ab0bb844
d278e7d424