[FIX] web: Discard from form view to form view

Clicking on the discard button in a form view whose previous view is
another form view wouldn't do anything.

This is fixed by making the view_manager trigger_up a history_back event
and then the history_back callback will handle cases in which there is
only one view and only one action, which used to be rejected

3 files changed, 13 insertions, 17 deletions

diff --git a/addons/web/static/src/js/chrome/action_manager.js b/addons/web/static/src/js/chrome/action_manager.js
index 94812302602..4dfc299e428 100644
--- a/addons/web/static/src/js/chrome/action_manager.js
+++ b/addons/web/static/src/js/chrome/action_manager.js
@@ -420,16 +420,20 @@ var ActionManager = Widget.extend({
         return this.inner_widget;
     },
     history_back: function() {
-        var nb_views = this.inner_action.get_nb_views();
-        if (nb_views > 1) {
+        var nbViews = this.inner_action.get_nb_views();
+        if (nbViews > 1) {
             // Stay on this action, but select the previous view
-            return this.select_action(this.inner_action, nb_views - 2);
+            return this.select_action(this.inner_action, nbViews - 2);
         }
-        if (this.action_stack.length > 1) {
+        var nbActions = this.action_stack.length;
+        if (nbActions > 1) {
             // Select the previous action
-            var action = this.action_stack[this.action_stack.length - 2];
-            nb_views = action.get_nb_views();
-            return this.select_action(action, nb_views - 1);
+            var action = this.action_stack[nbActions - 2];
+            nbViews = action.get_nb_views();
+            return this.select_action(action, nbViews - 1);
+        }
+        else if (nbActions === 1 && nbViews === 1) {
+            return this.select_action(this.action_stack[0], 0);
         }
         return $.Deferred().reject();
     },
diff --git a/addons/web/static/src/js/chrome/view_manager.js b/addons/web/static/src/js/chrome/view_manager.js
index eeccd9f1085..fcd823f440a 100644
--- a/addons/web/static/src/js/chrome/view_manager.js
+++ b/addons/web/static/src/js/chrome/view_manager.js
@@ -636,18 +636,10 @@ var ViewManager = Widget.extend(ControlPanelMixin, {
      * will call this very view manager to activate the previous view.
      * @todo: directly switch to previous view
      *
-     * A special case is done in the case that there is no previous view.  When
-     * that happens, we simply rerender the current view.
-     *
      * @private
      */
     _onSwitchToPreviousView: function () {
-        if (this.view_stack.length === 1) {
-            var currentView = this.view_stack[0].controller;
-            currentView.update({}, {reload: false});
-        } else {
-            this.do_action('history_back');
-        }
+        this.trigger_up('history_back');
     }
 });
 
diff --git a/addons/web/static/src/js/views/basic/basic_controller.js b/addons/web/static/src/js/views/basic/basic_controller.js
index 82dc6f90d26..cc72816a85d 100644
--- a/addons/web/static/src/js/views/basic/basic_controller.js
+++ b/addons/web/static/src/js/views/basic/basic_controller.js
@@ -250,7 +250,7 @@ var BasicController = AbstractController.extend(FieldManagerMixin, {
             on_fail: function (reason) {
                 reload().always(function() {
                     def.reject(reason);
-                })
+                });
             },
             on_success: def.resolve.bind(def),
         });