[FIX] base: ir.qweb.field.contact handle null value

In case where display_name is null, the widget contact crash
 - AttributeError: 'bool' object has no attribute 'split'

On odoo.com we have around 3K of partner that have name with null value.
So calling so widget Contact on linked res.users will crash since the
display name is False

closes odoo/odoo#155735

Signed-off-by: Rémy Voet (ryv) <ryv@odoo.com>

odoo/addons/base/models/ir_qweb_fields.py

@@ -781,15 +781,16 @@ class Contact(models.AbstractModel):
             opsep = Markup('<br/>')
 
         value = value.sudo().with_context(show_address=True)
+        display_name = value.display_name or ''
         # Avoid having something like:
         # display_name = 'Foo\n  \n' -> This is a res.partner with a name and no address
         # That would return markup('<br/>') as address. But there is no address set.
-        if any(elem.strip() for elem in value.display_name.split("\n")[1:]):
-            address = opsep.join(value.display_name.split("\n")[1:]).strip()
+        if any(elem.strip() for elem in display_name.split("\n")[1:]):
+            address = opsep.join(display_name.split("\n")[1:]).strip()
         else:
             address = ''
         val = {
-            'name': value.display_name.split("\n")[0],
+            'name': display_name.split("\n")[0],
             'address': address,
             'phone': value.phone,
             'mobile': value.mobile,

odoo/addons/base/tests/test_qweb.py

@@ -1644,6 +1644,21 @@ class TestQWebBasic(TransactionCase):
             markupsafe.Markup(f'<p>{p_instruction}</p>'),
             "Should have the processing instruction")
 
+    def test_render_widget_contact(self):
+        u = self.env['res.users'].create({
+            'name': 'Test',
+            'login': 'test@example.com',
+        })
+        u.name = ""
+        view1 = self.env['ir.ui.view'].create({
+            'name': "dummy",
+            'type': 'qweb',
+            'arch': """
+                <t t-name="base.dummy"><root><span t-esc="user" t-options='{"widget": "contact", "fields": ["name"]}' /></root></t>
+            """
+        })
+        self.env['ir.qweb']._render(view1.id, {'user': u})  # should not crash
+
     def test_void_element(self):
         view = self.env['ir.ui.view'].create({
             'name': 'master',