From efdbe4659aa82b32e5183896e3350d2380a68efb Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Mon, 17 Feb 2014 16:42:28 +0100
Subject: [PATCH] + fixes #0001418: Base::Matrix4d can't invert rotoinversion

---
 src/Base/MatrixPyImp.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Base/MatrixPyImp.cpp b/src/Base/MatrixPyImp.cpp
index e8d1625045a9..15aaac855cdb 100644
--- a/src/Base/MatrixPyImp.cpp
+++ b/src/Base/MatrixPyImp.cpp
@@ -341,7 +341,7 @@ PyObject* MatrixPy::invert(PyObject * args)
         return NULL;
 
     PY_TRY {
-        if (getMatrixPtr()->determinant() > DBL_EPSILON)
+        if (fabs(getMatrixPtr()->determinant()) > DBL_EPSILON)
             getMatrixPtr()->inverseGauss();
         else {
             PyErr_SetString(PyExc_Exception, "Cannot invert singular matrix");
@@ -359,7 +359,7 @@ PyObject* MatrixPy::inverse(PyObject * args)
         return NULL;
 
     PY_TRY {
-        if (getMatrixPtr()->determinant() > DBL_EPSILON) {
+        if (fabs(getMatrixPtr()->determinant()) > DBL_EPSILON) {
             Base::Matrix4D m = *getMatrixPtr();
             m.inverseGauss();
             return new MatrixPy(m);