fix errors if no custom field was selected

src/services/map-service.js

@@ -335,13 +335,19 @@ const mapService = {
     if (colors_style && colors_style.custom_field_name && customfield_set) {
       const fieldType = customfield_set.find((el) => el.name === colors_style.custom_field_name).field_type;
       const currentValue = properties[colors_style.custom_field_name];
-      if (fieldType === 'list') {
-        color = colors_style.colors[currentValue];
-        opacity = colors_style.opacities[currentValue];
-      } else if (fieldType === 'char') { //* if the custom field is supposed to be a string
-        //* check if its current value is empty or not, to select a color | https://redmine.neogeo.fr/issues/14048
-        color = colors_style.value.colors[currentValue ? 'Non vide' : 'Vide'];
-        opacity = colors_style.value.opacities[currentValue ? 'Non vide' : 'Vide'];
+
+      if (currentValue) {
+        switch (fieldType) {
+        case 'list' :
+          color = colors_style.colors[currentValue];
+          opacity = colors_style.opacities[currentValue];
+          break;
+        case 'char': //* if the custom field is supposed to be a string
+          //* check if its current value is empty or not, to select a color | https://redmine.neogeo.fr/issues/14048
+          color = colors_style.value.colors[currentValue ? 'Non vide' : 'Vide'];
+          opacity = colors_style.value.opacities[currentValue ? 'Non vide' : 'Vide'];
+          break;
+        }
       }
     }
     return { color, opacity };