2 files changed, 16 insertions, 5 deletions

diff --git a/addons/web_graph/static/src/js/graph.js b/addons/web_graph/static/src/js/graph.js
index 94c5a4011f9..450a86a470a 100644
--- a/addons/web_graph/static/src/js/graph.js
+++ b/addons/web_graph/static/src/js/graph.js
@@ -181,7 +181,8 @@ instance.web_graph.GraphView = instance.web.View.extend({
     do_search: function (domain, context, group_by) {
         this.pivot_table.domain = domain;
         if (group_by.length > 0) {
-            this.pivot_table.set_row_groupby(group_by).done(this.proxy('display_data'));
+            this.pivot_table.set_groupby(this.pivot_table.rows, group_by)
+                    .done(this.proxy('display_data'));
         } else {
             this.pivot_table.update_values().done(this.proxy('display_data'));            
         }
diff --git a/addons/web_graph/static/src/js/pivot.js b/addons/web_graph/static/src/js/pivot.js
index a9ef922819f..bca759a13e5 100644
--- a/addons/web_graph/static/src/js/pivot.js
+++ b/addons/web_graph/static/src/js/pivot.js
@@ -180,14 +180,24 @@ openerp.web_graph.PivotTable = openerp.web.Class.extend({
 		});
 	},
 
-	set_row_groupby: function (groupby) {
+	set_groupby: function (root, groupby) {
 		var self = this;
-		this.rows.groupby = groupby;
+		var other_root = (root === this.cols) ? this.rows : this.cols;
+
+		root.groupby = groupby;
 		return this.query_all_values().then(function (result) {
 			if (result) {
+				var new_root_headers, new_other_root_headers;
+				if (root === this.cols) {
+					new_root_headers = result.col_headers;
+					new_other_root_headers = result.how_headers;
+				} else {
+					new_root_headers = result.row_headers;
+					new_other_root_headers = result.col_headers;
+				}
 				self.no_data = false;
-				self.expand_headers(self.rows, result.row_headers);
-				self.update_headers(self.cols, result.col_headers);
+				self.expand_headers(root, new_root_headers);
+				self.update_headers(other_root, new_other_root_headers);
 				self.cells = result.cells;
 			} else {
 				self.no_data = true;