[Exit] in a popup menu now calls onPopupHandler(nullptr)

radio/src/gui/480x272/model_special_functions.cpp

@@ -56,7 +56,7 @@ void onCustomFunctionsFileSelectionMenu(const char * result)
       POPUP_WARNING(func==FUNC_PLAY_SCRIPT ? STR_NO_SCRIPTS_ON_SD : STR_NO_SOUNDS_ON_SD);
     }
   }
-  else {
+  else if (result) {
     // The user choosed a file in the list
     memcpy(cf->play.name, result, sizeof(cf->play.name));
     storageDirty(eeFlags);
@@ -128,7 +128,7 @@ void onAdjustGvarSourceLongEnterPress(const char * result)
     CFN_PARAM(cfn) = 0;
     storageDirty(EE_MODEL);
   }
-  else {
+  else if (result) {
     onSourceLongEnterPress(result);
   }
 }