[IMP] project(_issue): avoid stage reset at project change when it is shared among the new project

If the new project of the task or issue has the current record stage
among its own stages do not reset it. It avoids unnecessary changes and
chatter logs.

addons/project/models/project.py

@@ -434,7 +434,8 @@ class Task(models.Model):
         default_partner = self.env['res.partner'].browse(default_partner_id) if default_partner_id else None
         if self.project_id:
             self.partner_id = self.project_id.partner_id or default_partner
-            self.stage_id = self.stage_find(self.project_id.id, [('fold', '=', False)])
+            if self.project_id not in self.stage_id.project_ids:
+                self.stage_id = self.stage_find(self.project_id.id, [('fold', '=', False)])
         else:
             self.partner_id = default_partner
             self.stage_id = False

addons/project_issue/models/project_issue.py

@@ -132,7 +132,8 @@ class ProjectIssue(models.Model):
             if not self.partner_id and not self.email_from:
                 self.partner_id = self.project_id.partner_id.id
                 self.email_from = self.project_id.partner_id.email
-            self.stage_id = self.stage_find(self.project_id.id, [('fold', '=', False)])
+            if self.project_id not in self.stage_id.project_ids:
+                self.stage_id = self.stage_find(self.project_id.id, [('fold', '=', False)])
         else:
             self.partner_id = default_partner
             self.email_from = default_partner.email