kicad_cli fp ugrade: create directory with extension

pcbnew/pcb_io/pcb_io_mgr.cpp

@@ -198,6 +198,14 @@ bool PCB_IO_MGR::ConvertLibrary( STRING_UTF8_MAP* aOldFileProps, const wxString&
     wxArrayString fpNames;
     wxFileName newFileName( aNewFilePath );
 
+    if( newFileName.HasExt() )
+    {
+        wxString extraDir = newFileName.GetFullName();
+        newFileName.ClearExt();
+        newFileName.SetName( "" );
+        newFileName.AppendDir( extraDir );
+    }
+
     if( !newFileName.DirExists() && !wxFileName::Mkdir( aNewFilePath, wxS_DIR_DEFAULT ) )
         return false;
 
@@ -297,4 +305,4 @@ static PCB_IO_MGR::REGISTER_PLUGIN registerIPC2581Plugin(
         PCB_IO_MGR::IPC2581,
         wxT( "IPC-2581" ),
         []() -> PCB_IO* { return new PCB_IO_IPC2581; } );
-// clang-format on
+// clang-format on