well, we still mutate the passed in set of visited fragments....

Author: yaacovCR

spec/Section 6 -- Execution.md

@@ -590,17 +590,15 @@ CollectSubfields(objectType, fields, variableValues):
 - For each {field} in {fields}:
   - Let {fieldSelectionSet} be the selection set of {field}.
   - If {fieldSelectionSet} is null or empty, continue to the next field.
-  - Let {fieldGroupedFieldSet} and {fieldVisitedFragments} be the result of
-    calling {CollectFields(objectType, fragmentSelectionSet, variableValues,
+  - Let {fieldGroupedFieldSet} be the result of calling
+    {CollectFields(objectType, fragmentSelectionSet, variableValues,
     visitedFragments)}.
   - For each {fieldGroup} in {fieldGroupedFieldSet}:
     - Let {responseKey} be the response key shared by all fields in
       {fragmentGroup}.
     - Let {groupForResponseKey} be the list in {groupedFieldSet} for
       {responseKey}; if no such list exists, create it as an empty list.
     - Append all items in {fieldGroup} to {groupForResponseKey}.
-  - For each {fragmentSpreadName} in {fieldVisitedFragments}:
-    - Add {fragmentSpreadName} to {visitedFragments}.
 - Return {groupedSubfieldSet}.
 
 ## Executing Fields