[minor] optimized webnotes.has_permission
diff --git a/hr/doctype/leave_application/test_leave_application.py b/hr/doctype/leave_application/test_leave_application.py
index 7a900e3..48b502e 100644
--- a/hr/doctype/leave_application/test_leave_application.py
+++ b/hr/doctype/leave_application/test_leave_application.py
@@ -8,7 +8,7 @@
 
 class TestLeaveApplication(unittest.TestCase):
 	def tearDown(self):
-		webnotes.session.user = "Administrator"
+		webnotes.set_user("Administrator")
 		
 	def _clear_roles(self):
 		webnotes.conn.sql("""delete from `tabUserRole` where parent in 
@@ -19,7 +19,7 @@
 		
 	def _add_employee_leave_approver(self, employee, leave_approver):
 		temp_session_user = webnotes.session.user
-		webnotes.session.user = "Administrator"
+		webnotes.set_user("Administrator")
 		employee = webnotes.bean("Employee", employee)
 		employee.doclist.append({
 			"doctype": "Employee Leave Approver",
@@ -27,7 +27,7 @@
 			"leave_approver": leave_approver
 		})
 		employee.save()
-		webnotes.session.user = temp_session_user
+		webnotes.set_user(temp_session_user)
 	
 	def get_application(self, doclist):
 		application = webnotes.bean(copy=doclist)
@@ -49,7 +49,7 @@
 		application.doc.status = "Approved"
 		self.assertRaises(LeaveDayBlockedError, application.submit)
 		
-		webnotes.session.user = "test1@example.com"
+		webnotes.set_user("test1@example.com")
 
 		# clear other applications
 		webnotes.conn.sql("delete from `tabLeave Application`")
@@ -65,7 +65,7 @@
 		add_role("test@example.com", "Employee")
 		add_role("test2@example.com", "Leave Approver")
 		
-		webnotes.session.user = "test@example.com"
+		webnotes.set_user("test@example.com")
 		application = self.get_application(test_records[1])
 		application.doc.leave_approver = "test2@example.com"
 		application.insert()
@@ -89,10 +89,10 @@
 		webnotes.conn.set_value("Employee", "_T-Employee-0002", "department", 
 			"_Test Department")
 		
-		webnotes.session.user = "test1@example.com"
+		webnotes.set_user("test1@example.com")
 		application.insert()
 		
-		webnotes.session.user = "test@example.com"
+		webnotes.set_user("test@example.com")
 		application.doc.status = "Approved"
 		self.assertRaises(LeaveDayBlockedError, application.submit)
 		
@@ -116,13 +116,13 @@
 		self._clear_applications()
 		
 		# create leave application as Employee
-		webnotes.session.user = "test@example.com"
+		webnotes.set_user("test@example.com")
 		application = self.get_application(test_records[1])
 		application.doc.leave_approver = "test1@example.com"
 		application.insert()
 		
 		# submit leave application by Leave Approver
-		webnotes.session.user = "test1@example.com"
+		webnotes.set_user("test1@example.com")
 		application.doc.status = "Approved"
 		application.submit()
 		self.assertEqual(webnotes.conn.get_value("Leave Application", application.doc.name,
@@ -139,7 +139,7 @@
 		
 		# TODO - add test2@example.com leave approver in employee's leave approvers list
 		application = self.get_application(test_records[1])
-		webnotes.session.user = "test@example.com"
+		webnotes.set_user("test@example.com")
 		
 		application.doc.leave_approver = "test1@example.com"
 		self.assertRaises(InvalidLeaveApproverError, application.insert)
@@ -153,11 +153,11 @@
 		
 		# create leave application as employee
 		# but submit as invalid leave approver - should raise exception
-		webnotes.session.user = "test@example.com"
+		webnotes.set_user("test@example.com")
 		application = self.get_application(test_records[1])
 		application.doc.leave_approver = "test2@example.com"
 		application.insert()
-		webnotes.session.user = "test1@example.com"
+		webnotes.set_user("test1@example.com")
 		application.doc.status = "Approved"
 		
 		from webnotes.model.bean import BeanPermissionError
@@ -173,13 +173,13 @@
 		original_department = webnotes.conn.get_value("Employee", "_T-Employee-0001", "department")
 		webnotes.conn.set_value("Employee", "_T-Employee-0001", "department", None)
 		
-		webnotes.session.user = "test@example.com"
+		webnotes.set_user("test@example.com")
 		application = self.get_application(test_records[1])
 		application.doc.leave_approver = "test2@example.com"
 		application.insert()
 
 		# change to valid leave approver and try to submit leave application
-		webnotes.session.user = "test2@example.com"
+		webnotes.set_user("test2@example.com")
 		application.doc.status = "Approved"
 		application.submit()
 		self.assertEqual(webnotes.conn.get_value("Leave Application", application.doc.name,