[1D] Initialize number-of-steps counter at start of solve

Fixes the enforcement of the maximum number of steps constraint if solve() is
called again after an exception.

include/cantera/oneD/OneDim.h

@@ -340,6 +340,12 @@ class OneDim
     //! Function called at the start of every call to #eval.
     Func1* m_interrupt;
 
+    //! Number of time steps taken in the current call to solve()
+    int m_nsteps;
+
+    //! Maximum number of timesteps allowed per call to solve()
+    int m_nsteps_max;
+
 private:
     // statistics
     int m_nevals;
@@ -350,12 +356,6 @@ class OneDim
     vector_int m_funcEvals;
     vector_fp m_funcElapsed;
 
-    //! Number of time steps taken in the current call to solve()
-    int m_nsteps;
-
-    //! Maximum number of timesteps allowed per call to solve()
-    int m_nsteps_max;
-
     //! Number of time steps taken in each call to solve() (e.g. for each
     //! successive grid refinement)
     vector_int m_timeSteps;

src/oneD/OneDim.cpp

@@ -18,8 +18,8 @@ OneDim::OneDim()
       m_bw(0), m_size(0),
       m_init(false), m_pts(0), m_solve_time(0.0),
       m_ss_jac_age(20), m_ts_jac_age(20),
-      m_interrupt(0), m_nevals(0), m_evaltime(0.0), m_nsteps(0),
-      m_nsteps_max(500)
+      m_interrupt(0), m_nsteps(0), m_nsteps_max(500),
+      m_nevals(0), m_evaltime(0.0)
 {
     m_newt.reset(new MultiNewton(1));
 }
@@ -30,8 +30,8 @@ OneDim::OneDim(vector<Domain1D*> domains) :
     m_bw(0), m_size(0),
     m_init(false), m_solve_time(0.0),
     m_ss_jac_age(20), m_ts_jac_age(20),
-    m_interrupt(0), m_nevals(0), m_evaltime(0.0), m_nsteps(0),
-    m_nsteps_max(500)
+    m_interrupt(0), m_nsteps(0), m_nsteps_max(500),
+    m_nevals(0), m_evaltime(0.0)
 {
     // create a Newton iterator, and add each domain.
     m_newt.reset(new MultiNewton(1));
@@ -364,7 +364,7 @@ doublereal OneDim::timeStep(int nsteps, doublereal dt, doublereal* x,
                 dt *= 1.5;
             }
             dt = std::min(dt, m_tmax);
-            if (m_nsteps == m_nsteps_max) {
+            if (m_nsteps >= m_nsteps_max) {
                 throw CanteraError("OneDim::timeStep",
                     "Took maximum number of timesteps allowed ({}) without "
                     "reaching steady-state solution.", m_nsteps_max);

src/oneD/Sim1D.cpp

@@ -230,6 +230,7 @@ void Sim1D::solve(int loglevel, bool refine_grid)
     int new_points = 1;
     int nsteps;
     doublereal dt = m_tstep;
+    m_nsteps = 0;
     int soln_number = -1;
     finalize();