fix: Remove zero-amount payments during POS session validation.

.gitignore

@@ -0,0 +1,66 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
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+parts/
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+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
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+
+# Unit test / coverage reports
+htmlcov/
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+nosetests.xml
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+*.cover
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+# Translations
+*.pot
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+
+# Odoo specific
+*.log
+filestore/
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+# System
+.DS_Store
+Thumbs.db

README.md

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+# POS Cash Opening Adjustment
+
+**Version:** 17.0.1.0.0  
+**Author:** Suherdy Yacob  
+**Category:** Point of Sale  
+**License:** LGPL-3
+
+## Summary
+Prevent opening cash journal entries and exclude opening float from closing totals while keeping reconciliation data.
+
+## Features
+- **Opening Cash Adjustment:** Modifies how opening cash is handled to prevent unwanted journal entries.
+- **Closing Totals:** Excludes opening float from closing totals calculation.
+- **Zero-Amount Payment Cleanup:** Automatically removes `pos.payment` lines with `0.00` amount during session verification. This prevents the creation of "Difference at closing PoS session" journal items triggered by empty payments (e.g. from 100% discount or external payment edge cases).
+
+## Technical Details
+### Zero-Amount Payment Fix
+The module overrides `_validate_session` in `pos.session`. Before the standard validation process begins, it iterates through all orders in the session and unlinks any payment lines where the amount is considered zero by the session's currency.

models/pos_session.py

@@ -132,4 +132,12 @@ class PosSession(models.Model):
                 "expected_amount": expected_total,
                 "amount": expected_total,
             })
-        return data
+        return data
+
+    def _validate_session(self, balancing_account=False, amount_to_balance=0, bank_payment_method_diffs=None):
+        for session in self:
+            for order in session.order_ids:
+                for payment in order.payment_ids:
+                    if session.currency_id.is_zero(payment.amount):
+                        payment.unlink()
+        return super(PosSession, self)._validate_session(balancing_account, amount_to_balance, bank_payment_method_diffs)