[ADD]allow_negative_leave_and_allocation:allow negative leave

allow_negative_leave_and_allocation/models/__init__.py

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+from . import hr_leave_type, hr_leave

allow_negative_leave_and_allocation/models/hr_leave.py

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+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+# Copyright (c) 2005-2006 Axelor SARL. (http://www.axelor.com)
+
+from odoo import api, models
+
+class HrLeave(models.Model):
+    _inherit = "hr.leave"
+
+    @api.constrains('state', 'number_of_days', 'holiday_status_id')
+    def _check_holidays(self):
+        for holiday in self:
+            if holiday.holiday_status_id.allows_negative:
+                continue
+            super()._check_holidays()

allow_negative_leave_and_allocation/models/hr_leave_type.py

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+
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from odoo import api, fields, models
+
+
+class HolidaysType(models.Model):
+    _inherit = "hr.leave.type"
+
+    # negative time off
+    allows_negative = fields.Boolean(string='Allow Negative Cap',
+        help="If checked, users request can exceed the allocated days and balance can go in negative.")
+
+    @api.depends('requires_allocation')
+    def _compute_valid(self):
+        res = super()._compute_valid()
+        for holiday_type in res:
+            if not holiday_type.has_valid_allocation:
+                holiday_type.has_valid_allocation = holiday_type.allows_negative