[FIX] account_statement_import: don't raise an error when a multi-statement file has one empty statement

When I created the module account_statement_import in v14, I added
support for multi-statement files. In the current implementation, if one
statement is empty, it raises an error which blocks the import of the
other statements that had transactions. This commit fixes this.

account_statement_import/wizard/account_statement_import.py

@@ -36,6 +36,13 @@ class AccountStatementImport(models.TransientModel):
         file_data = base64.b64decode(self.statement_file)
         self.import_single_file(file_data, result)
         logger.debug("result=%s", result)
+        if not result["statement_ids"]:
+            raise UserError(
+                _(
+                    "You have already imported this file, or this file "
+                    "only contains already imported transactions."
+                )
+            )
         self.env["ir.attachment"].create(self._prepare_create_attachment(result))
         if self.env.context.get("return_regular_interface_action"):
             action = (
@@ -101,7 +108,8 @@ class AccountStatementImport(models.TransientModel):
             )
         currency_code, account_number, stmts_vals = single_statement_data
         # Check raw data
-        self._check_parsed_data(stmts_vals)
+        if not self._check_parsed_data(stmts_vals):
+            return False
         if not currency_code:
             raise UserError(_("Missing currency code in the bank statement file."))
         # account_number can be None (example : QIF)
@@ -161,9 +169,14 @@ class AccountStatementImport(models.TransientModel):
         )
 
     def _check_parsed_data(self, stmts_vals):
-        """ Basic and structural verifications """
+        """
+        Basic and structural verifications.
+        Return False when empty data (don't raise en error, because we
+        support multi-statement files and we don't want one empty
+        statement to block the import of others)
+        """
         if len(stmts_vals) == 0:
-            raise UserError(_("This file doesn't contain any statement."))
+            return False
 
         no_st_line = True
         for vals in stmts_vals:
@@ -171,7 +184,8 @@ class AccountStatementImport(models.TransientModel):
                 no_st_line = False
                 break
         if no_st_line:
-            raise UserError(_("This file doesn't contain any transaction."))
+            return False
+        return True
 
     @api.model
     def _match_currency(self, currency_code):
@@ -345,12 +359,7 @@ class AccountStatementImport(models.TransientModel):
                 statement_ids.append(statement.id)
 
         if not statement_ids:
-            raise UserError(
-                _(
-                    "You have already imported this file, or this file "
-                    "only contains already imported transactions."
-                )
-            )
+            return False
         result["statement_ids"].extend(statement_ids)
 
         # Prepare import feedback