fix(fusion_clock): code-review hardening [19.0.5.0.1]

- _cron_generate: per-rule savepoint isolation (one bad rule can't abort the
  whole daily batch)
- fclk_attach_recurrence: clear an existing recurrence first (no orphaned rule
  generating forever)
- fclk_apply_planner_cell: collapse split rows (search was limit=1 after the
  UNIQUE drop, orphaning extras)
- fclk_release_shift: reject non-posted/open shifts (raw-POST guard)
- delete_open_shift: report success=false when nothing was deleted + JS surfaces it
- _generate: log before removing an empty recurrence
Tests added for collapse, re-attach, draft-release.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

fusion_clock/models/clock_recurrence.py

@@ -96,7 +96,9 @@ class FusionClockScheduleRecurrence(models.Model):
             seed = Schedule.search(
                 [('recurrence_id', '=', rec.id)], order='schedule_date desc', limit=1)
             if not seed:
-                # No anchor row -> nothing to repeat; drop the empty rule.
+                # No anchor row left -> nothing to repeat; drop the empty rule.
+                _logger.info(
+                    "Fusion Clock: recurrence %s has no shifts left; removing it.", rec.id)
                 rec.unlink()
                 continue
             anchor = Schedule.search(
@@ -150,5 +152,13 @@ class FusionClockScheduleRecurrence(models.Model):
 
     @api.model
     def _cron_generate(self):
-        """Roll every recurrence's horizon forward (called daily)."""
-        self.search([])._generate()
+        """Roll every recurrence's horizon forward (called daily). Each rule is
+        isolated in its own savepoint so one bad recurrence can't abort
+        generation for all the others."""
+        for rec in self.search([]):
+            try:
+                with self.env.cr.savepoint():
+                    rec._generate()
+            except Exception:
+                _logger.exception(
+                    "Fusion Clock: recurrence %s failed to generate; skipping.", rec.id)

fusion_clock/models/clock_schedule.py

@@ -332,16 +332,21 @@ class FusionClockSchedule(models.Model):
         if not employee.exists() or not date_obj:
             raise ValidationError(_("Invalid employee or schedule date."))
 
-        existing = self.search([
+        # The UNIQUE(employee, date) constraint was dropped to allow split
+        # shifts, so a day can hold several rows. The planner cell is the single
+        # authoritative entry for the day: an edit collapses to one row, a clear
+        # removes them all. (Open shifts have no employee, so they never match.)
+        same_day = self.search([
             ('employee_id', '=', employee.id),
             ('schedule_date', '=', date_obj),
-        ], limit=1)
+        ], order='id')
+        existing = same_day[:1]
         old_value = self.fclk_snapshot(existing)
         parsed = self.fclk_values_from_planner_payload(payload, employee)
 
         if parsed.get('clear'):
-            if existing:
-                existing.unlink()
+            if same_day:
+                same_day.unlink()
             new_schedule = self.browse()
             new_value = ''
         else:
@@ -373,6 +378,7 @@ class FusionClockSchedule(models.Model):
             if existing:
                 existing.write(vals)
                 new_schedule = existing
+                (same_day - existing).unlink()  # collapse any split rows into one
             else:
                 new_schedule = self.create(vals)
             new_value = new_schedule.fclk_display_value()
@@ -446,6 +452,10 @@ class FusionClockSchedule(models.Model):
         schedule = schedule.sudo()
         if not schedule:
             raise ValidationError(_("Pick a shift to repeat first."))
+        # Replace any existing recurrence so we never orphan a rule that would
+        # otherwise keep generating shifts forever.
+        if schedule.recurrence_id:
+            self.fclk_clear_recurrence(schedule)
         rule = self.env['fusion.clock.schedule.recurrence'].sudo().create({
             'repeat_interval': int(repeat_vals.get('repeat_interval') or 1),
             'repeat_unit': repeat_vals.get('repeat_unit') or 'week',
@@ -517,6 +527,8 @@ class FusionClockSchedule(models.Model):
         schedule = schedule.sudo()
         if not schedule or schedule.employee_id != employee.sudo():
             raise ValidationError(_("You can only release your own shift."))
+        if schedule.state != 'posted' or schedule.is_open:
+            raise ValidationError(_("Only a posted shift assigned to you can be released."))
         cutoff = schedule.company_id.fclk_self_unassign_days_before or 0
         if (schedule.schedule_date - fields.Date.today()).days < cutoff:
             raise ValidationError(_("It is too late to release this shift."))