Added the is_check_as parameter to the get_txn_op function so that the "as" query parameter is not checked when showing the transaction detail.

src/accounting/transaction/operators.py

@@ -304,15 +304,17 @@ TXN_TYPE_TO_OP: dict[TransactionType, TransactionOperator] \
 """The map from the transaction types to their operators."""
 
 
-def get_txn_op(txn: Transaction) -> TransactionOperator:
+def get_txn_op(txn: Transaction, is_check_as: bool = False) \
+        -> TransactionOperator:
     """Returns the transaction operator that may be specified in the "as" query
     parameter.  If it is not specified, check the transaction type from the
     transaction.
 
     :param txn: The transaction.
+    :param is_check_as: True to check the "as" parameter, or False otherwise.
     :return: None.
     """
-    if "as" in request.args:
+    if is_check_as and "as" in request.args:
         type_dict: dict[str, TransactionType] \
             = {x.value: x for x in TransactionType}
         if request.args["as"] not in type_dict:

src/accounting/transaction/views.py

@@ -111,7 +111,7 @@ def show_transaction_edit_form(txn: Transaction) -> str:
     :param txn: The transaction.
     :return: The form to edit the transaction.
     """
-    txn_op: TransactionOperator = get_txn_op(txn)
+    txn_op: TransactionOperator = get_txn_op(txn, is_check_as=True)
     form: txn_op.form
     if "form" in session:
         form = txn_op.form(ImmutableMultiDict(parse_qsl(session["form"])))
@@ -131,7 +131,7 @@ def update_transaction(txn: Transaction) -> redirect:
     :return: The redirection to the transaction detail on success, or the
         transaction edit form on error.
     """
-    txn_op: TransactionOperator = get_txn_op(txn)
+    txn_op: TransactionOperator = get_txn_op(txn, is_check_as=True)
     form: txn_op.form = txn_op.form(request.form)
     if not form.validate():
         flash_form_errors(form)