[FIX] web: form: call discardChanges while saving

Before this rev., there was a race condition when the user did
some changes on a form view (triggering an onchange), saved and
clicked on the breadcrumbs to leave the form view (before the
onchange returned). As a consequence, the dialog telling the user
that there are pending changes was displayed. This mostly occured
on the main_flow_tour since the removal of an unnecessary check,
and could be reproduced manually on a slow network.

Basically, the check if there were pending changes was done too
early (before the view was actually saved).

1 files changed, 9 insertions, 3 deletions

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 76adef0a154..01bbd9cd2fe 100644
--- a/addons/web/static/src/js/views/basic/basic_controller.js
+++ b/addons/web/static/src/js/views/basic/basic_controller.js
@@ -38,6 +38,10 @@ var BasicController = AbstractController.extend(FieldManagerMixin, {
         FieldManagerMixin.init.call(this, this.model);
         this.handle = params.initialState.id;
         this.mode = params.mode || 'readonly';
+        // savingDef is used to ensure that we always wait for pending save
+        // operations to complete before checking if there are changes to
+        // discard when discardChanges is called
+        this.savingDef = $.when();
     },
     /**
      * @override
@@ -102,14 +106,15 @@ var BasicController = AbstractController.extend(FieldManagerMixin, {
         return true;
     },
     /**
-     * Waits for the mutex to be unlocked and then calls _.discardChanges.
+     * Waits for the mutex to be unlocked and for changes to be saved, then
+     * calls _.discardChanges.
      * This ensures that the confirm dialog isn't displayed directly if there is
      * a pending 'write' rpc.
      *
      * @see _.discardChanges
      */
     discardChanges: function (recordID, options) {
-        return this.mutex.exec(function () {})
+        return $.when(this.mutex.getUnlockedDef(), this.savingDef)
             .then(this._discardChanges.bind(this, recordID || this.handle, options));
     },
     /**
@@ -183,11 +188,12 @@ var BasicController = AbstractController.extend(FieldManagerMixin, {
         // mutex-protected as commitChanges function of x2m has to be aware of
         // all final changes made to a row.
         var self = this;
-        return this.mutex.getUnlockedDef().then(function () {
+        this.savingDef = this.mutex.getUnlockedDef().then(function () {
             return self.renderer.commitChanges(recordID || self.handle).then(function () {
                 return self.mutex.exec(self._saveRecord.bind(self, recordID, options));
             });
         });
+        return this.savingDef;
     },
     /**
      * @override