Prevent saving record for readonly screen

Closes #13885

sao/src/tab.js

@@ -887,7 +887,7 @@
                 this.screen.save_tree_state();
             }
             var access = Sao.common.MODELACCESS.get(this.screen.model_name);
-            if (!(access.write || access.create)) {
+            if (this.screen.readonly || !(access.write || access.create)) {
                 return jQuery.Deferred().reject();
             }
             return this.screen.save_current().then(

tryton/tryton/gui/window/form.py

@@ -469,9 +469,9 @@ class Form(TabContent):
         if widget:
             # Called from button so we must save the tree state
             self.screen.save_tree_state()
-        if not (common.MODELACCESS[self.model]['write']
-                or common.MODELACCESS[self.model]['create']
-                or self.screen.writable):
+        if (self.screen.readonly
+                or not (common.MODELACCESS[self.model]['write']
+                    or common.MODELACCESS[self.model]['create'])):
             return
         if self.screen.save_current():
             self.info_bar_add(_('Record saved.'), Gtk.MessageType.INFO)