title: Odoo - search_default does not work?
body: <p>I created button in partner form to show another models relation with it. It is same button like Opportunities, Meetings, Sales button at partners form showing all its Opportunities, Meetings, Sales etc.</p>
  
  <p>Code looks like this:</p>
  
  <p><strong>Model:</strong></p>
  
  <pre><code>from openerp import models, fields
  from openerp import api
  class res_partner(models.Model):
      _inherit = 'res.partner'
  
      service_ids = fields.One2many('calendar.service', 'partner_id', 'Calendar Services')
      service_count = fields.Integer('Services', compute='_count_services')
  
      @api.one
      @api.depends('service_ids')
      def _count_services(self):
          self.service_count = len(self.service_ids)
  </code></pre>
  
  <p><strong>Action:</strong></p>
  
  <pre><code>    &lt;record id="action_calendar_service" model="ir.actions.act_window"&gt;
          &lt;field name="name"&gt;Services&lt;/field&gt;
          &lt;field name="res_model"&gt;calendar.service&lt;/field&gt;
          &lt;field name="view_mode"&gt;tree,calendar,form&lt;/field&gt;
          &lt;field name="view_id" ref="view_calendar_service_tree"/&gt;
          &lt;field name="search_view_id" ref="view_calendar_service_search"/&gt;
          &lt;field name="help" type="html"&gt;
            &lt;p class="oe_view_nocontent_create"&gt;
              Click to create new service.
            &lt;/p&gt;
          &lt;/field&gt;
      &lt;/record&gt;
  </code></pre>
  
  <p><strong>View:</strong></p>
  
  <pre><code>    &lt;record id="view_partners_form_service1" model="ir.ui.view"&gt;
          &lt;field name="name"&gt;view.res.partner.form.crm.inherited1&lt;/field&gt;
          &lt;field name="model"&gt;res.partner&lt;/field&gt;
          &lt;field name="inherit_id" ref="crm.view_partners_form_crm1"/&gt;
          &lt;field eval="18" name="priority"/&gt;
          &lt;field name="arch" type="xml"&gt;
                  &lt;button name="schedule_meeting" position="after"&gt;
                      &lt;button
                          class="oe_inline oe_stat_button"
                          attrs="{'invisible': [('customer', '=', False)]}"
                          name="%(calendar_service.action_calendar_service)d"
                          icon="fa-star"
                          type="action"
                          context="{'search_default_partner_id': active_id}"&gt;
                          &lt;field name="service_count" string="Services" widget="statinfo"/&gt;
                      &lt;/button&gt;
                  &lt;/button&gt;
          &lt;/field&gt;
      &lt;/record&gt;
  </code></pre>
  
  <p>Everything works with that button except for one thing. It does not filter result with <code>partner_id</code> (the one that button was pressed) and it opens all 'calendar.service' records. But it should show only the ones from that specific partner. Does <code>context="{'search_default_partner_id': active_id}"&gt;</code> need something more? What am I missing here?</p>