[FIX] web: various bugs with pivot view and no data

The pivot view had various small issues causing a crash when
transitioning from and to a 'no data' state.

addons/web/static/src/js/views/pivot/pivot_controller.js

@@ -171,11 +171,13 @@ var PivotController = AbstractController.extend({
      */
     _update: function (state) {
         this._updateButtons();
-        var hasNoContent = !state.measures.length || !state.has_data;
+        var hasNoContent = !state.has_data || !state.measures.length;
 
         if (hasNoContent) {
-            this.renderer.$el.detach();
-            this.$el.append(QWeb.render('PivotView.nodata'));
+            if (!this.$('.oe_view_nocontent').length) {
+                this.renderer.$el.detach();
+                this.$el.append(QWeb.render('PivotView.nodata'));
+            }
         } else {
             if (!document.contains(this.renderer.el)) {
                 this.$('div.oe_view_nocontent').remove();

addons/web/static/src/js/views/pivot/pivot_model.js

@@ -186,11 +186,14 @@ var PivotModel = AbstractModel.extend({
      */
     get: function (options) {
         var isRaw = options && options.raw;
+        if (!this.data.has_data) {
+            return {has_data: false};
+        }
         return {
             colGroupBys: this.data.main_col.groupbys,
             fields: this.fields,
-            has_data: this.data.has_data,
             headers: !isRaw && this._computeHeaders(),
+            has_data: true,
             mainColWidth: this.data.main_col.width,
             measures: this.data.measures,
             rows: !isRaw && this._computeRows(),
@@ -243,8 +246,6 @@ var PivotModel = AbstractModel.extend({
      */
     reload: function (handle, params) {
         var self = this;
-        var old_row_root = this.data.main_row.root;
-        var old_col_root = this.data.main_col.root;
         if ('domain' in params) {
             this.data.domain = params.domain;
         } else {
@@ -253,7 +254,12 @@ var PivotModel = AbstractModel.extend({
         if ('groupBy' in params) {
             this.data.groupedBy = params.groupBy;
         }
+        if (!this.data.has_data) {
+            return this._loadData(params);
+        }
 
+        var old_row_root = this.data.main_row.root;
+        var old_col_root = this.data.main_col.root;
         return this._loadData(params).then(function () {
             var new_groupby_length;
             if (!('groupBy' in params)) {

addons/web/static/src/js/views/pivot/pivot_renderer.js

@@ -18,6 +18,9 @@ var PivotRenderer = AbstractRenderer.extend({
      * @returns {Deferred}
      */
     _render: function () {
+        if (!this.state.has_data) {
+            return this._super.apply(this, arguments);
+        }
         var $fragment = $(document.createDocumentFragment());
         var $table = $('<table>').appendTo($fragment);
         var $thead = $('<thead>').appendTo($table);

addons/web/static/test/views/pivot_tests.js

@@ -389,6 +389,53 @@ QUnit.module('Views', {
         pivot.destroy();
     });
 
+    QUnit.test('no content helper when no data, part 2', function (assert) {
+        assert.expect(1);
+
+        this.data.partner.records = [];
+
+        var pivot = createView({
+            View: PivotView,
+            model: "partner",
+            data: this.data,
+            arch: '<pivot string="Partners"></pivot>',
+        });
+
+        assert.strictEqual(pivot.$('.oe_view_nocontent').length, 1,
+            "should have a no_content_helper");
+        pivot.destroy();
+    });
+
+    QUnit.test('no content helper when no data, part 3', function (assert) {
+        assert.expect(4);
+
+        var pivot = createView({
+            View: PivotView,
+            model: "partner",
+            data: this.data,
+            arch: '<pivot string="Partners"></pivot>',
+            viewOptions: {
+                domain: [['foo', '=', 12345]]
+            },
+        });
+
+        assert.strictEqual(pivot.$('.oe_view_nocontent').length, 1,
+            "should have a no_content_helper");
+        pivot.update({domain: [['foo', '=', 12345]]});
+        assert.strictEqual(pivot.$('.oe_view_nocontent').length, 1,
+            "should still have a no_content_helper");
+        pivot.update({domain: []});
+        assert.strictEqual(pivot.$('.oe_view_nocontent').length, 0,
+            "should not have a no_content_helper");
+
+        // tries to open a field selection menu, to make sure it was not
+        // removed from the dom.
+        pivot.$('.o_pivot_header_cell_closed').first().click();
+        assert.strictEqual(pivot.$('ul.o_pivot_field_menu').length, 1,
+            "the field selector menu exists");
+        pivot.destroy();
+    });
+
     QUnit.test('tries to restore previous state after domain change', function (assert) {
         assert.expect(5);