[FIX] analytic: plans without account but with subplan can appear

If we have an analytic plan without analytic accounts, but with
subplans that do have analytic accounts, we do want them to
appear in the widget.

Also changed a search in a loop to a read_group

closes odoo/odoo#142222

Signed-off-by: William André (wan) <wan@odoo.com>

addons/analytic/models/analytic_plan.py

@@ -147,8 +147,15 @@ class AccountAnalyticPlan(models.Model):
 
     @api.depends('account_ids', 'children_ids')
     def _compute_all_analytic_account_count(self):
+        plans_count = dict(
+            self.env['account.analytic.account']._read_group(
+                domain=[('root_plan_id', 'in', self.ids)],
+                aggregates=['id:count'],
+                groupby=['root_plan_id']
+            )
+        )
         for plan in self:
-            plan.all_account_count = self.env['account.analytic.account'].search_count([('plan_id', "child_of", plan.id)])
+            plan.all_account_count = plans_count.get(plan, 0)
 
     @api.depends('children_ids')
     def _compute_children_count(self):
@@ -185,7 +192,7 @@ class AccountAnalyticPlan(models.Model):
         record_account_ids = kwargs.get('existing_account_ids', [])
         project_plan, other_plans = self.env['account.analytic.plan']._get_all_plans()
         root_plans = (project_plan + other_plans).filtered(lambda p: (
-            bool(p.account_ids)
+            p.all_account_count > 0
             and not p.parent_id
             and p._get_applicability(**kwargs) != 'unavailable'
         ))