Prevent crash on failure to load ngspice's dll

Fixes https://gitlab.com/kicad/code/kicad/-/issues/20695


(cherry picked from commit f35078cb29)

Co-authored-by: Marek Roszko <mark.roszko@gmail.com>

common/kiway.cpp

@@ -452,8 +452,9 @@ KIWAY_PLAYER* KIWAY::Player( FRAME_T aFrameType, bool doCreate, wxTopLevelWindow
                                             m_ctl       // questionable need, these same flags
                                                         // were passed to KIFACE::OnKifaceStart()
                                             );
+            if( frame )
+                m_playerFrameId[aFrameType].store( frame->GetId() );
 
-            m_playerFrameId[aFrameType].store( frame->GetId() );
             return frame;
         }
         catch( ... )

eeschema/eeschema.cpp

@@ -191,8 +191,17 @@ static struct IFACE : public KIFACE_BASE, public UNITS_PROVIDER
 
         case FRAME_SIMULATOR:
         {
-            SIMULATOR_FRAME* frame = new SIMULATOR_FRAME( aKiway, aParent );
-            return frame;
+            try
+            {
+                SIMULATOR_FRAME* frame = new SIMULATOR_FRAME( aKiway, aParent );
+                return frame;
+            }
+            catch( SIMULATOR_INIT_ERR )
+            {
+                // catch the init err exception as we don't want it to bubble up
+                // its going to be some ngspice install issue but we don't want to log that
+                return nullptr;
+            }
         }
 
         case FRAME_SCH_VIEWER:

eeschema/sim/ngspice.cpp

@@ -498,7 +498,7 @@ void NGSPICE::init_dll()
 #endif
 
     if( !m_dll.IsLoaded() )
-        throw std::runtime_error( "Missing ngspice shared library" );
+        throw std::runtime_error( _( "Unable to load ngspice shared library. Please check your install." ).ToStdString() );
 
     m_error = false;
 

eeschema/sim/simulator_frame.cpp

@@ -145,7 +145,9 @@ SIMULATOR_FRAME::SIMULATOR_FRAME( KIWAY* aKiway, wxWindow* aParent ) :
     mainSizer->Add( m_ui, 1, wxEXPAND, 5 );
 
     m_simulator = SIMULATOR::CreateInstance( "ngspice" );
-    wxASSERT( m_simulator );
+
+    if( !m_simulator )
+        throw SIMULATOR_INIT_ERR( "Failed to create simulator instance" );
 
     LoadSettings( config() );
 

eeschema/sim/simulator_frame.h

@@ -49,6 +49,18 @@ class ACTION_TOOLBAR;
 class SPICE_SIMULATOR;
 
 
+/**
+ * Simple error container for failure to init the simulation engine
+ * and ultimately abort the frame construction
+ */
+class SIMULATOR_INIT_ERR : public std::runtime_error
+{
+public:
+    explicit SIMULATOR_INIT_ERR(const std::string& what_arg)
+        : std::runtime_error(what_arg) {}
+};
+
+
 /**
  *
  * The SIMULATOR_FRAME holds the main user-interface for running simulations.