misc: apply canonical field name transformation

CHANGES.md

@@ -10,6 +10,7 @@ Features:
  * Add Button to Center the loaded image in the Image Slice Window.
  * Add "Created At", "Last Modified At" columns to card list.
  * Add filter box to Game and Stylesheet selection.
+ * Add extra_card("field name") script function for accessing Extra Card Fields.
 
 ------------------------------------------------------------------------------
 HEAD: new items added as changes are made

src/script/functions/editor.cpp

@@ -391,8 +391,12 @@ SCRIPT_FUNCTION(extra_data) {
   SCRIPT_PARAM_C(CardP, card);
   SCRIPT_PARAM_C(StyleSheetP, stylesheet);
 
+  // Transform input to standard field name syntax.
+  // Other functions are doing lookups for ValuePs, which I assume is doing some of this automatically.
+  String canonical_field_name = canonical_name_form(input);
+
   FOR_EACH(valueP, card->extraDataFor(*stylesheet)) {
-    if (valueP->fieldP->name == input) {
+    if (valueP->fieldP->name == canonical_field_name) {
       SCRIPT_RETURN(valueP);
     }
   }