Fix

booking.py

@@ -77,6 +77,10 @@ class Booking(Workflow, ModelSQL, ModelView):
         states={
             'readonly': Bool(Eval('lines')),
         }, depends=['state', 'company', 'lines'])
+    rate_plan = fields.Many2One('hotel.rate_plan', 'Rate Plan',
+        states={
+            'readonly': Bool(Eval('lines')),
+        }, depends=['state', 'company', 'lines'])
     company = fields.Many2One('company.company', 'Company', required=True,
         states=STATES, domain=[('id', If(In('company',
         Eval('context', {})), '=', '!='), Get(Eval('context', {}),

rate_plan.py

@@ -9,7 +9,7 @@ from trytond.model import ModelView, ModelSQL, fields, Workflow
 class RatePlan(Workflow, ModelSQL, ModelView):
     'Hotel Rate Plan'
     __name__ = 'hotel.rate_plan'
-    _rec_name = "price_list"
+    # _rec_name = "price_list"
     price_list = fields.Many2One('product.price_list', 'Price List',
             required=True)
     start_date = fields.Date('Start Date', required=True)
@@ -101,6 +101,9 @@ class RatePlan(Workflow, ModelSQL, ModelView):
         if self.end_date and self.start_date:
             return (self.end_date - self.start_date).days
 
+    def get_rec_name(self, name):
+        return self.price_list.name
+
 
 class RatePlanRule(ModelSQL, ModelView):
     'Hotel Rate Plan'

view/booking_form.xml

@@ -20,8 +20,8 @@ this repository contains the full copyright notices and license terms. -->
     <field name="media"/>
     <label name="plan"/>
     <field name="plan"/>
-    <label name="price_list"/>
-    <field name="price_list" widget="selection"/>
+    <label name="rate_plan"/>
+    <field name="rate_plan" widget="selection"/>
     <label name="payment_term"/>
     <field name="payment_term" widget="selection"/>
     <label name="space"/>
@@ -63,6 +63,8 @@ this repository contains the full copyright notices and license terms. -->
             <field name="company"/>
             <label name="currency"/>
             <field name="currency"/>
+            <label name="price_list"/>
+            <field name="price_list" widget="selection"/>
             <label name="credit_card"/>
             <field name="credit_card"/>
             <label name="guarantee"/>