Enforce unique names for is_set columns on first_value and last_value

Author: marc-pydantic

datafusion/functions-aggregate/src/first_last.rs

@@ -166,7 +166,7 @@ impl AggregateUDFImpl for FirstValue {
         )
         .into()];
         fields.extend(args.ordering_fields.iter().cloned());
-        fields.push(Field::new("is_set", DataType::Boolean, true).into());
+        fields.push(Field::new(format_state_name(args.name, "first_value_is_set"), DataType::Boolean, true).into());
         Ok(fields)
     }
 
@@ -1087,7 +1087,7 @@ impl AggregateUDFImpl for LastValue {
         )
         .into()];
         fields.extend(args.ordering_fields.iter().cloned());
-        fields.push(Field::new("is_set", DataType::Boolean, true).into());
+        fields.push(Field::new(format_state_name(args.name, "last_value_is_set"), DataType::Boolean, true).into());
         Ok(fields)
     }