fix: update dimesions in exchange_gain_loss jv based on base document

erpnext/controllers/accounts_controller.py

@@ -1339,6 +1339,12 @@ class AccountsController(TransactionBase):
 		# Cancelling existing exchange gain/loss journals is handled during the `on_cancel` event.
 		# see accounts/utils.py:cancel_exchange_gain_loss_journal()
 		if self.docstatus == 1:
+			if dimensions_dict is None:
+				dimensions_dict = frappe._dict()
+				active_dimensions = get_dimensions()[0]
+				for dim in active_dimensions:
+					dimensions_dict[dim.fieldname] = self.get(dim.fieldname)
+
 			if self.get("doctype") == "Journal Entry":
 				# 'args' is populated with exchange gain/loss account and the amount to be booked.
 				# These are generated by Sales/Purchase Invoice during reconciliation and advance allocation.