AD routines do not handle linear functions properly

[svigerske]

Issue created by migration from Trac.

Original creator: @h-i-gassmann

Original creation time: 2017-01-22 02:46:30

Assignee: @h-i-gassmann

Version:

A "nonlinear" expression containing only a scalar multiple of a decision variable is not handled properly when the variable is also mentioned in the linear part. In the worst case this can lead to a segmentation fault, because it will try to access the wrong element of the sparse Jacobian.