[FIX] web: allow virtual ids for integer fields

Before this change, the redering throw an exception when we try to open
a form view with a virtual id.
eg: recurrent event in calendar

addons/web/static/tests/fields/basic_fields_tests.js

@@ -1521,6 +1521,31 @@ QUnit.module('basic_fields', {
         form.destroy();
     });
 
+    QUnit.test('integer field in form view with virtual id', function(assert) {
+        assert.expect(2);
+        var params = {
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch:'<form string="Partners"><field name="id"/></form>',
+        };
+
+        params.res_id = this.data.partner.records[1].id = "2-20170808020000";
+        var form = createView(params);
+        assert.strictEqual(form.$('.o_form_field').text(), "2-20170808020000",
+            "Should display virtual id");
+        form.destroy();
+
+        params.res_id = this.data.partner.records[1].id = "2.65-20170808020000";
+        try {
+            form = createView(params);
+        } catch (error) {
+            assert.strictEqual(error.message, '"2.65-20170808020000" is not an integer or a virtual id',
+                "Should throw an exception because it's a wrong value");
+        }
+        form.destroy();
+    });
+
     QUnit.test('integer field in editable list view', function (assert) {
         assert.expect(4);