comphy-lab · pull · Jul 15, 2026 · Jul 10, 2026 · Jul 10, 2026 · Jul 10, 2026
diff --git a/doc/src/Developer_unittest.rst b/doc/src/Developer_unittest.rst
@@ -777,6 +777,17 @@ are:
        for this style.  The fix rejects a timestep reset (its
        ``Fix::reset_dt()`` raises an error, e.g. :doc:`fix move
        <fix_move>`), which would otherwise abort the test.
+   * - no_restart
+     - The ``fix_timestep`` tester skips the restarted-run comparisons
+       for this style.  Part of the internal state of the fix (typically
+       the pRNG state of a stochastic fix like :doc:`fix langevin
+       <fix_langevin>`) is not stored in restart files, so a restarted
+       run cannot reproduce the reference trajectory.
+   * - no_t_target
+     - The ``fix_timestep`` tester does not compare the extracted
+       ``t_target`` property against the input variable for this style,
+       because the fix computes its target temperature internally (e.g.
+       the :doc:`fix nphug <fix_nphug>` hugoniostat).
    * - ellipsoid
      - The test includes ellipsoids and thus requires :doc:`fix
        nve/asphere <fix_nve_asphere>`.
@@ -795,8 +806,10 @@ are:
        platforms, e.g. ARM64; Until a proper correction is found, tests
        can be skipped with ``ctest -LE unstable``.
    * - generated
-     - Indicates that a test input was regenerated. *Remove* after
-       confirming the correctness of the updated YAML file.
+     - Automatically added whenever reference data is generated or
+       regenerated; it marks data that has not been reviewed and
+       validated yet.  *Remove* after confirming the correctness of the
+       updated YAML file.
 
 Additional tests will check whether all listed extract keywords are
 supported and have the correct dimensionality and the final set of tests

diff --git a/src/BROWNIAN/fix_propel_self.cpp b/src/BROWNIAN/fix_propel_self.cpp
@@ -26,6 +26,8 @@
 #include "domain.h"
 #include "error.h"
 #include "math_extra.h"
+#include "respa.h"
+#include "update.h"
 
 #include <cmath>
 #include <cstring>
@@ -40,7 +42,8 @@ static constexpr double SMALL = 1.0e-14;
 
 /* ---------------------------------------------------------------------- */
 
-FixPropelSelf::FixPropelSelf(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg), avec(nullptr)
+FixPropelSelf::FixPropelSelf(LAMMPS *lmp, int narg, char **arg) :
+    Fix(lmp, narg, arg), ilevel_respa(0), avec(nullptr)
 {
 
   virial_global_flag = virial_peratom_flag = 1;
@@ -100,6 +103,12 @@ int FixPropelSelf::setmask()
 
 void FixPropelSelf::init()
 {
+  if (utils::strmatch(update->integrate_style, "^respa")) {
+    int max_respa = (dynamic_cast<Respa *>(update->integrate))->nlevels - 1;
+    ilevel_respa = max_respa;
+    if (respa_level >= 0) ilevel_respa = MIN(respa_level, max_respa);
+  }
+
   if (mode == DIPOLE && !atom->mu_flag)
     error->all(FLERR, Error::NOLASTLINE,
                "Fix propel/self with option dipole requires atom attribute mu");
@@ -129,7 +138,20 @@ void FixPropelSelf::init()
 
 void FixPropelSelf::setup(int vflag)
 {
-  post_force(vflag);
+  if (utils::strmatch(update->integrate_style, "^verlet"))
+    post_force(vflag);
+  else {
+    (dynamic_cast<Respa *>(update->integrate))->copy_flevel_f(ilevel_respa);
+    post_force_respa(vflag, ilevel_respa, 0);
+    (dynamic_cast<Respa *>(update->integrate))->copy_f_flevel(ilevel_respa);
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixPropelSelf::post_force_respa(int vflag, int ilevel, int /*iloop*/)
+{
+  if (ilevel == ilevel_respa) post_force(vflag);
 }
 
 /* ---------------------------------------------------------------------- */

diff --git a/src/BROWNIAN/fix_propel_self.h b/src/BROWNIAN/fix_propel_self.h
@@ -29,13 +29,15 @@ class FixPropelSelf : public Fix {
 
   void init() override;
   void post_force(int) override;
+  void post_force_respa(int, int, int) override;
   void setup(int) override;
   int setmask() override;
 
  private:
   double magnitude;
   double sx, sy, sz;
   int mode;
+  int ilevel_respa;
 
   void post_force_dipole(int);
   void post_force_velocity(int);

diff --git a/src/EXTRA-FIX/fix_electron_stopping_fit.cpp b/src/EXTRA-FIX/fix_electron_stopping_fit.cpp
@@ -131,6 +131,9 @@ void FixElectronStoppingFit::init()
   f_dot_v_prior = 0.;
   f_dot_v_current = 0.;
   last_step = update->ntimestep;
+
+  if (utils::strmatch(update->integrate_style, "^respa"))
+    nlevels_respa = (dynamic_cast<Respa *>(update->integrate))->nlevels;
 };
 
 // ---------------------------------------------------------------------

diff --git a/src/EXTRA-FIX/fix_ffl.cpp b/src/EXTRA-FIX/fix_ffl.cpp
@@ -60,6 +60,7 @@ FixFFL::FixFFL(LAMMPS *lmp, int narg, char **arg) :
   restart_peratom = 1;
   time_integrate = 1;
   scalar_flag = 1;
+  extscalar = 1;
 
   //gamma = 1 / time constant(tau)
   gamma = utils::numeric(FLERR,arg[3],false,lmp);

diff --git a/src/EXTRA-FIX/fix_wall_reflect_stochastic.cpp b/src/EXTRA-FIX/fix_wall_reflect_stochastic.cpp
@@ -181,6 +181,11 @@ FixWallReflectStochastic(LAMMPS *lmp, int narg, char **arg) :
   // random number generator
 
   random = new RanMars(lmp,seedfix + comm->me);
+
+  // must re-create the dump image graphics objects: the base class
+  // constructor sized them before the walls were parsed here
+
+  allocate_image_objects();
 }
 
 /* ---------------------------------------------------------------------- */

diff --git a/src/fix_wall_reflect.cpp b/src/fix_wall_reflect.cpp
@@ -144,6 +144,20 @@ FixWallReflect::FixWallReflect(LAMMPS *lmp, int narg, char **arg) :
     if (wallstyle[m] == VARIABLE) varflag = 1;
 
   // for rendering walls with dump image.
+  allocate_image_objects();
+}
+
+/* ----------------------------------------------------------------------
+   (re-)create the graphics objects for rendering walls with dump image.
+   must be (re-)done after parsing the walls, since derived classes
+   (e.g. fix wall/reflect/stochastic) parse their arguments themselves
+   and may arrive at a different wall count than the base class parser.
+------------------------------------------------------------------------- */
+
+void FixWallReflect::allocate_image_objects()
+{
+  memory->destroy(imgobjs);
+  memory->destroy(imgparms);
   if (domain->dimension == 2) {
     // one cylinder object per wall to draw in 2d
     memory->create(imgobjs, nwall, "fix_wall_reflect:imgobjs");

diff --git a/src/fix_wall_reflect.h b/src/fix_wall_reflect.h
@@ -47,6 +47,7 @@ class FixWallReflect : public Fix {
   int *imgobjs;
   double **imgparms;
 
+  void allocate_image_objects();
   virtual void wall_particle(int m, int which, double coord);
 };
 

diff --git a/unittest/force-styles/test_config.h b/unittest/force-styles/test_config.h
@@ -125,13 +125,14 @@ class TestConfig {
 
     [[nodiscard]] std::string tags_line() const
     {
-        if (tags.size() > 0) {
-            std::string line = tags[0];
-            for (std::size_t i = 1; i < tags.size(); i++)
-                line += " " + tags[i];
-            return line;
-        }
-        return "generated";
+        // the "generated" tag is ALWAYS added when reference data is
+        // (re-)generated: it marks data that has not been reviewed and
+        // validated yet and is removed manually as the last step after
+        // validation.  all other tags are passed through.
+        std::string line;
+        for (const auto &tag : tags)
+            if (tag != "generated") line += tag + " ";
+        return line + "generated";
     }
 
     // check whether a given keyword is present in the "tags:" list. used by the

diff --git a/unittest/force-styles/test_fix_timestep.cpp b/unittest/force-styles/test_fix_timestep.cpp
@@ -119,6 +119,13 @@ LAMMPS *init_lammps(LAMMPS::argv &args, const TestConfig &cfg, const bool use_re
 
 void restart_lammps(LAMMPS *lmp, const TestConfig &cfg, bool use_rmass, bool use_respa)
 {
+    // styles tagged "no_restart" cannot reproduce the reference trajectory
+    // from a restart because part of their internal state (typically the RNG
+    // state of a stochastic fix) is not stored in restart files.  skip the
+    // restarted run; the comparisons that follow then re-examine the still
+    // loaded final state of the normal run and pass trivially.
+    if (test_config.has_tag("no_restart")) return;
+
     // utility lambda to improve readability
     auto command = [&](const std::string &line) {
         lmp->input->one(line);
@@ -358,11 +365,13 @@ TEST(FixTimestep, plain)
                                       epsilon);
         }
 
-        // check t_target for thermostats
+        // check t_target for thermostats.  styles tagged "no_t_target"
+        // compute their target temperature internally (e.g. a hugoniostat),
+        // so it cannot be compared to the input variable.
 
         int dim   = -1;
         auto *ptr = (double *)ifix->extract("t_target", dim);
-        if ((ptr != nullptr) && (dim == 0)) {
+        if ((ptr != nullptr) && (dim == 0) && !test_config.has_tag("no_t_target")) {
             int ivar = lmp->input->variable->find("t_target");
             if (ivar >= 0) {
                 double t_ref    = atof(lmp->input->variable->retrieve("t_target"));
@@ -677,11 +686,13 @@ TEST(FixTimestep, omp)
                                       epsilon);
         }
 
-        // check t_target for thermostats
+        // check t_target for thermostats.  styles tagged "no_t_target"
+        // compute their target temperature internally (e.g. a hugoniostat),
+        // so it cannot be compared to the input variable.
 
         int dim   = -1;
         auto *ptr = (double *)ifix->extract("t_target", dim);
-        if ((ptr != nullptr) && (dim == 0)) {
+        if ((ptr != nullptr) && (dim == 0) && !test_config.has_tag("no_t_target")) {
             int ivar = lmp->input->variable->find("t_target");
             if (ivar >= 0) {
                 double t_ref    = atof(lmp->input->variable->retrieve("t_target"));
@@ -1002,7 +1013,7 @@ static void run_kokkos_test(LAMMPS::argv &args)
 
         int dim     = -1;
         double *ptr = (double *)ifix->extract("t_target", dim);
-        if ((ptr != nullptr) && (dim == 0)) {
+        if ((ptr != nullptr) && (dim == 0) && !test_config.has_tag("no_t_target")) {
             int ivar = lmp->input->variable->find("t_target");
             if (ivar >= 0) {
                 double t_ref    = atof(lmp->input->variable->retrieve("t_target"));

diff --git a/unittest/force-styles/tests/compute-ackland_atom.yaml b/unittest/force-styles/tests/compute-ackland_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:32 2026
 epsilon: 1e-08
 timestep: 0.001

diff --git a/unittest/force-styles/tests/compute-adf.yaml b/unittest/force-styles/tests/compute-adf.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:37:03 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-aggregate_atom.yaml b/unittest/force-styles/tests/compute-aggregate_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:17 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-angle_local.yaml b/unittest/force-styles/tests/compute-angle_local.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:47 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-angmom_chunk.yaml b/unittest/force-styles/tests/compute-angmom_chunk.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:33:56 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-basal_atom.yaml b/unittest/force-styles/tests/compute-basal_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:33 2026
 epsilon: 1e-08
 timestep: 0.001

diff --git a/unittest/force-styles/tests/compute-bond_local.yaml b/unittest/force-styles/tests/compute-bond_local.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:46 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-centro_atom.yaml b/unittest/force-styles/tests/compute-centro_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:49 2026
 epsilon: 1e-08
 timestep: 0.001

diff --git a/unittest/force-styles/tests/compute-chunk_atom.yaml b/unittest/force-styles/tests/compute-chunk_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:33:55 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-chunk_spread_atom.yaml b/unittest/force-styles/tests/compute-chunk_spread_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:03 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-cluster_atom.yaml b/unittest/force-styles/tests/compute-cluster_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:16 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-cna_atom.yaml b/unittest/force-styles/tests/compute-cna_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:48 2026
 epsilon: 1e-08
 timestep: 0.001

diff --git a/unittest/force-styles/tests/compute-com.yaml b/unittest/force-styles/tests/compute-com.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:37 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-com_chunk.yaml b/unittest/force-styles/tests/compute-com_chunk.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:42 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-coord_atom.yaml b/unittest/force-styles/tests/compute-coord_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:43 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-dihedral_local.yaml b/unittest/force-styles/tests/compute-dihedral_local.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:21 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-dipole.yaml b/unittest/force-styles/tests/compute-dipole.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:38 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-dipole_chunk.yaml b/unittest/force-styles/tests/compute-dipole_chunk.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:00 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-displace_atom.yaml b/unittest/force-styles/tests/compute-displace_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:21:44 2026
 epsilon: 1e-08
 timestep: 0.25

diff --git a/unittest/force-styles/tests/compute-entropy_atom.yaml b/unittest/force-styles/tests/compute-entropy_atom.yaml
@@ -1,6 +1,6 @@
 ---
 lammps_version: 4 Jul 2026
-tags: generated
+tags:
 date_generated: Thu Jul  9 16:34:34 2026
 epsilon: 1e-08
 timestep: 0.001