eeschema: workaround for 64kByte string length limit in wxString::Format() causing segfaults in netlist update under Windows

Fixes: lp:1754402
* https://bugs.launchpad.net/kicad/+bug/1754402

common/kiway.cpp

@@ -384,7 +384,7 @@ bool KIWAY::PlayersClose( bool doForce )
 
 
 void KIWAY::ExpressMail( FRAME_T aDestination,
-                MAIL_T aCommand, const std::string& aPayload, wxWindow* aSource )
+                MAIL_T aCommand, std::string aPayload, wxWindow* aSource )
 {
     KIWAY_EXPRESS   mail( aDestination, aCommand, aPayload, aSource );
 

eeschema/sch_edit_frame.cpp

@@ -907,13 +907,12 @@ void SCH_EDIT_FRAME::doUpdatePcb( const wxString& aUpdateOptions )
 
     exporter.Format( &formatter, GNL_ALL );
 
-    // Copy the netlist in a static string, to have a long life time
-    // and giving to Pcbnew the time to analyze this netlist:
-    static std::string netlist_string;
-    netlist_string = wxString::Format("%s\n%s", aUpdateOptions, formatter.GetString() ).ToStdString();
+    auto updateOptions = aUpdateOptions.ToStdString();
+    auto netlistString = formatter.GetString();
+    auto finalNetlist = updateOptions + "\n" + netlistString;
 
     // Now, send the "kicad" (s-expr) netlist to Pcbnew
-    Kiway().ExpressMail( FRAME_PCB, MAIL_SCH_PCB_UPDATE, netlist_string, this );
+    Kiway().ExpressMail( FRAME_PCB, MAIL_SCH_PCB_UPDATE, finalNetlist, this );
 }
 
 

include/kiway.h

@@ -344,7 +344,7 @@ public:
      * aCommand in there.
      */
     VTBL_ENTRY void ExpressMail( FRAME_T aDestination, MAIL_T aCommand,
-            const std::string& aPayload, wxWindow* aSource = NULL );
+            std::string aPayload, wxWindow* aSource = NULL );
 
     /**
      * Function Prj