[FIX] account_ebics - Number duplicate upload file names before the extension

A duplicate upload name got the counter appended to the previous
candidate and after the extension: pay.xml_1, then pay.xml_1_2,
pay.xml_1_2_3. Keep the extension and number from the original name:
pay_1.xml, pay_2.xml.

account_ebics/tests/test_ebics_xfer.py

@@ -190,14 +190,20 @@ class TestEbicsXferUpload(EbicsTestCommon):
         self.assertFalse(self.ebics_config.order_number)
 
     def test_upload_same_name_twice(self):
+        """The counter goes before the extension and does not stack up."""
         names = []
-        for _i in range(3):
+        for _i in range(4):
             wizard = self._upload_wizard(self.ff_btu)
             with self._fake_client(FakeEbicsClient()):
                 names.append(wizard._ebics_upload().name)
-        # Pinned, probably unintended: _update_ef_vals appends each counter to
+        self.assertEqual(names, ["pay.xml", "pay_1.xml", "pay_2.xml", "pay_3.xml"])
-        # the previous candidate (pay.xml_1_2) instead of pay.xml_2.
+        # without extension
-        self.assertEqual(names, ["pay.xml", "pay.xml_1", "pay.xml_1_2"])
+        wizard = self._upload_wizard(self.ff_btu, fname="pay")
+        with self._fake_client(FakeEbicsClient()):
+            self.assertEqual(wizard._ebics_upload().name, "pay")
+        wizard = self._upload_wizard(self.ff_btu, fname="pay")
+        with self._fake_client(FakeEbicsClient()):
+            self.assertEqual(wizard._ebics_upload().name, "pay_1")
 
     def test_upload_ful_h003_order_number(self):
         self.ebics_config.write({"ebics_version": "H003", "order_number": "A00Z"})

account_ebics/wizards/ebics_xfer.py

@@ -3,6 +3,7 @@
 
 import base64
 import logging
+import os
 from sys import exc_info
 from traceback import format_exception
 
@@ -578,11 +579,13 @@ class EbicsXfer(models.TransientModel):
             fn = ef_vals["name"]
             dups = self._check_duplicate_ebics_file(fn, self.format_id)
             if dups:
+                # pay.xml -> pay_1.xml, pay_2.xml, ...
+                base, ext = os.path.splitext(fn)
                 n = 1
-                fn = "_".join([fn, str(n)])
+                fn = f"{base}_{n}{ext}"
                 while self._check_duplicate_ebics_file(fn, self.format_id):
                     n += 1
-                    fn = "_".join([fn, str(n)])
+                    fn = f"{base}_{n}{ext}"
                 ef_vals["name"] = fn
 
     def _handle_download_data(self, data, file_format):