..

Author: dweindl

src/model.cpp

@@ -2875,19 +2875,21 @@ void Model::fdwdp(realtype const t, realtype const* x, bool include_static) {
 }
 
 void Model::fdwdx(realtype const t, realtype const* x, bool include_static) {
+    // NOTE: (at least) Model_{ODE,DAE}::fJSparse rely on `fw` and `fdwdw`
+    //  being called from here. They need to be executed even if nx_solver==0.
     if (!nw)
         return;
 
     fw(t, x, include_static);
 
     derived_state_.dwdx_.zero();
     if (pythonGenerated) {
-        auto dwdx_hierarchical_0 = derived_state_.dwdx_hierarchical_.at(0);
+        fdwdw(t, x, include_static);
+
+        auto&& dwdx_hierarchical_0 = derived_state_.dwdx_hierarchical_.at(0);
         if (!dwdx_hierarchical_0.data() || !dwdx_hierarchical_0.capacity())
             return;
 
-        fdwdw(t, x, include_static);
-
         if (include_static) {
             dwdx_hierarchical_0.zero();
             fdwdx_colptrs(dwdx_hierarchical_0);