Switch the view when user cancel the new record

Closes #14583
(grafted from 86b3db529010f8fa36dfee4949f160f77298efc3)

--HG--
branch : 7.0

sao/src/tab.js

@@ -856,7 +856,9 @@
             });
         },
         switch_: function() {
-            return this.modified_save().then(() => this.screen.switch_view());
+            return this.modified_save().then(
+                () => this.screen.switch_view(),
+                (result) => result ? this.screen.switch_view() : null);
         },
         reload: function(test_modified=true) {
             const reload = () => {

tryton/tryton/gui/window/form.py

@@ -292,7 +292,8 @@ class Form(TabContent):
         update('note', label, 'tryton-note', badge)
 
     def sig_switch(self, widget=None):
-        if not self.modified_save():
+        result = self.modified_save()
+        if not result and result is not None:
             return
         self.screen.switch_view()