diff -Naur meshlab.orig/src/meshlabplugins/edit_quality/eqhandle.cpp meshlab/src/meshlabplugins/edit_quality/eqhandle.cpp
--- meshlab.orig/src/meshlabplugins/edit_quality/eqhandle.cpp	2016-10-30 14:07:42.211338698 +0100
+++ meshlab/src/meshlabplugins/edit_quality/eqhandle.cpp	2016-10-30 14:08:26.774164177 +0100

@@ -30,6 +30,7 @@
 #include "eqhandle.h"
 #include <QMouseEvent>
 #include <QGraphicsSceneMouseEvent>
+#include "math.h" /* fabs() */
 
 EqHandle::EqHandle(CHART_INFO *environment_info, QColor color, QPointF position, 
 				   EQUALIZER_HANDLE_TYPE type, EqHandle** handles, qreal* midHandlePercentilePosition, QDoubleSpinBox* spinbox,
@@ -83,7 +83,7 @@
 	setCursor(Qt::OpenHandCursor);
 
 	QPointF newPos = event->scenePos();
-	qreal handleOffset = abs(newPos.x()-pos().x());
+	qreal handleOffset = fabs(newPos.x()-pos().x());
 
 	if (handleOffset >= std::numeric_limits<float>::epsilon())
 	{