[FIX] web: correct column title when kanban grouped

Before this commit, when a kanban view was grouped by a selection field, the
column were named with the raw value of the selection instead of the display
string.

Furthermore, fix the fact that when the column title was 0 or False,
'undefined' was displayed instead.

addons/web/static/src/js/views/basic/basic_model.js

@@ -2470,6 +2470,15 @@ var BasicModel = AbstractModel.extend({
                             aggregateValues[key] = value;
                         }
                     });
+                    // When a view is grouped, we need to display the name of each group in
+                    // the 'title'.
+                    var value = group[rawGroupBy];
+                    if (list.fields[rawGroupBy].type === "selection") {
+                        var choice = _.find(list.fields[rawGroupBy].selection, function (c) {
+                            return c[0] === value;
+                        });
+                        value = choice[1];
+                    }
                     var newGroup = self._makeDataPoint({
                         modelName: list.model,
                         count: group[rawGroupBy + '_count'],
@@ -2477,7 +2486,7 @@ var BasicModel = AbstractModel.extend({
                         context: list.context,
                         fields: list.fields,
                         fieldsInfo: list.fieldsInfo,
-                        value: group[rawGroupBy],
+                        value: value,
                         aggregateValues: aggregateValues,
                         groupedBy: list.groupedBy.slice(1),
                         orderedBy: list.orderedBy,

addons/web/static/src/js/views/kanban/kanban_column.js

@@ -39,12 +39,8 @@ var KanbanColumn = Widget.extend({
 
         var value = data.value;
         this.id = data.res_id || value;
-        var field = data.fields[data.groupedBy[0]]; // fixme: grouped by field might not be in the fvg
-        if (field && field.type === "selection") {
-            value = _.find(field.selection, function (s) { return s[0] === data.value; })[1]; // fixme: same process done in list_renderer
-        }
         // todo: handle group_by_m2o (nameget)
-        this.title = value || _t('Undefined');
+        this.title = value === undefined ? _t('Undefined') : value;
         this.folded = !data.isOpen;
         this.has_active_field = 'active' in data.fields;
         this.size = data.count;

addons/web/static/src/js/views/list/list_renderer.js

@@ -172,24 +172,6 @@ var ListRenderer = BasicRenderer.extend({
                 return decoration.replace('decoration', 'text');
             }).value();
     },
-    /**
-     * When a list view is grouped, we need to display the name of each group in
-     * the 'title' row.  This is the purpose of this method.
-     *
-     * @private
-     * @param {any} value
-     * @param {Object} field a field description
-     * @returns {string}
-     */
-    _formatValue: function (value, field) {
-        if (field && field.type === 'selection') {
-            var choice = _.find(field.selection, function (c) {
-                return c[0] === value;
-            });
-            return choice[1];
-        }
-        return value || _t('Undefined');
-    },
     /**
      * return the number of visible columns.  Note that this number depends on
      * the state of the renderer.  For example, in editable mode, it could be
@@ -409,8 +391,7 @@ var ListRenderer = BasicRenderer.extend({
         if (this.hasSelectors) {
             $cells.unshift($('<td>'));
         }
-        var field = this.state.fields[this.state.groupedBy[groupLevel]];
-        var name = this._formatValue(group.value, field);
+        var name = group.value === undefined ? _t('Undefined') : group.value;
         var $th = $('<th>')
                     .addClass('o_group_name')
                     .text(name + ' (' + group.count + ')');