Ensure face-station relation is rebuilt if a multipart nc file is loa…

…ded which invalidates this relationship

src/core.cpp

@@ -2425,7 +2425,7 @@ void core::run()
             else
             {
                 // loading a new netcdf will invalidate all our stations, so we need to rebuild the list of stations
-                if(_metdata->is_multipart_nc())
+                if(_metdata->is_multipart_nc() && _metdata->nc_just_loaded())
                     populate_face_station_lists();
             }
 

src/metdata.cpp

@@ -31,6 +31,7 @@ metdata::metdata(std::string mesh_proj4)
     _mesh_proj4 = mesh_proj4;
     is_first_timestep = true;
     _is_multipart_nc = false;
+    _just_loaded_nc = false;
 
     OGRSpatialReference srs;
     srs.importFromProj4(_mesh_proj4.c_str());
@@ -96,6 +97,7 @@ void metdata::load_from_netcdf(const std::string& path, const triangulation::bou
     SPDLOG_DEBUG("Found NetCDF file {}", path);
 
     _use_netcdf = true;
+    _just_loaded_nc = true;
     _nc = std::make_unique<netcdf>();
 
     // only do this once, don't repeat if we have them cached
@@ -690,9 +692,18 @@ bool metdata::next_ascii()
 
     return true;
 }
+
+bool metdata::nc_just_loaded()
+{
+    return _just_loaded_nc;
+}
+
 bool metdata::next_nc()
 {
 
+    // assume we won't have to load a netcdf
+    _just_loaded_nc = false;
+
     //_current_ts is already ++ from the next() call
     if(!_is_multipart_nc && (_current_ts > _end_time))
     {

src/metdata.hpp

@@ -166,6 +166,14 @@ class metdata
     std::string start_time_str();
     std::string end_time_str();
 
+    /**
+     * Returns true if a netcdf was just loaded.
+     * Calling next() without having to load a multipart will cause this to begin to return false
+     **/
+    bool nc_just_loaded();
+
+    ///
+    /// @return
     bool is_multipart_nc();
 
     /**
@@ -265,6 +273,7 @@ class metdata
         // Mapped w/ stations ID -> metdata
         std::map<std::string, std::unique_ptr<ascii_data>> _ascii_stations;
 
+
     // -----------------------------------
 
     // This is a different approach than how stations used to work
@@ -282,6 +291,7 @@ class metdata
     size_t _n_timesteps;
 
     bool _is_multipart_nc;
+    bool _just_loaded_nc; // if a nc file was just loaded
 
     // These two are the start and end time of the simulation. If we have loaded from a single file
     // these will be equal to file_*. However, if we are loading from a multi-part file then the file_*