Symbolic Jacobian is not generated for systems with one state

[Lennart Ochel]

Just a simple example:

model foo
  Real x1(start=1.0, fixed=true);
equation
  der(x1) = 0;
end foo;

The LOG_SOLVER dump indicates that there is something wrong with the generated symbolic jacobian:

LOG_SOLVER        | info    | sparse structure of jacobian A [size: 0x0]

In fact, there is no symbolic Jacobian generated. But if the model get extended by a second state, then the Jacobian is generated as expected:

model foo
  Real x1(start=1.0, fixed=true);
  Real x2(start=1.0, fixed=true);
equation
  der(x1) = 0;
  der(x2) = 0;
end foo;

LOG_SOLVER        | info    | sparse structure of jacobian A [size: 2x2]
|                 | |       | | 0 nonzero elements
|                 | |       | | transposed sparse structure (rows: states)
|                 | |       | | |
|                 | |       | | |

[Lennart Ochel]

fixed with bf6ce68/OMCompiler

[Dietmar Winkler]

It doesn't make sense to keep closed ticket in the "Future" milestone that were simply forgotten to assign to the correct milestone in the past.

[Martin Sjölund]

Removing the pre1.9.4 milestone in favor of 1.9.4.