Fix tail position

css/app.css

@@ -1509,6 +1509,20 @@ a.success-action {
     border-width: 5px 0 5px 5px;
 }
 
+.left.tail::after {
+    content: "";
+    position: absolute;
+    width: 0;
+    height: 0;
+    border-color: transparent;
+    border-style: solid;
+    top: 50%;
+    left: -5px;
+    margin-top: -5px;
+    border-right-color: white;
+    border-width: 5px 5px 5px 0;
+}
+
 .tooltip-arrow {
     position: absolute;
     width: 0;

js/lib/d3.tail.js

@@ -33,6 +33,7 @@ d3.tail = function() {
             if (text === false) return;
             var xoffset = ((d3.event.clientX + tooltip_size[0] + xmargin) > selection_size[0]) ?
                 -tooltip_size[0] - xmargin : xmargin;
+            container.classed('left', xoffset > 0);
             container.style(transformProp, 'translate(' +
                 (~~d3.event.clientX + xoffset) + 'px,' +
                 ~~d3.event.clientY + 'px)');