Handle STEP export properly on MacOS when launched from standalone pcbnew.

pcbnew/dialogs/dialog_export_step.cpp

@@ -249,6 +249,17 @@ void DIALOG_EXPORT_STEP::onExportButton( wxCommandEvent& aEvent )
     double yOrg = 0.0;
 
     wxFileName appK2S( wxStandardPaths::Get().GetExecutablePath() );
+    #ifdef __WXMAC__
+    // On macOS, we have standalone applications inside the main bundle, so we handle that here:
+        if( appK2S.GetPath().find( _("/Contents/Applications/pcbnew.app/Contents/MacOS") ) != wxNOT_FOUND )
+        {
+            appK2S.AppendDir( _(".."));
+            appK2S.AppendDir( _(".."));
+            appK2S.AppendDir( _(".."));
+            appK2S.AppendDir( _(".."));
+            appK2S.AppendDir( _("MacOS"));
+        }
+    #endif
     appK2S.SetName( "kicad2step" );
 
     wxString cmdK2S = "\"";

pcbnew/pcb_edit_frame.cpp

@@ -518,7 +518,12 @@ PCB_EDIT_FRAME::PCB_EDIT_FRAME( KIWAY* aKiway, wxWindow* aParent ) :
     // disable Export STEP item if kicad2step does not exist
     wxString strK2S = Pgm().GetExecutablePath();
     #ifdef __WXMAC__
-        strK2S += "Contents/MacOS/";
+    if (strK2S.find( _("pcbnew.app") ) != wxNOT_FOUND )
+    {
+        // On macOS, we have standalone applications inside the main bundle, so we handle that here:
+        strK2S += "../../";
+    }
+    strK2S += "Contents/MacOS/";
     #endif
     wxFileName appK2S( strK2S, "kicad2step" );