From cbdcce0d642e4a07bbcc7a7466d50cf0c7e75b6b Mon Sep 17 00:00:00 2001
From: msv <msv@opencascade.com>
Date: Wed, 25 Jan 2017 18:12:18 +0300
Subject: [PATCH] 0028375: Regressions after enabling floating point signals
 handling in DRAW

In Bisector_BisecCC.cxx avoid division by zero when the variable N1P2P1==0.
In Bisector_BisecPC.cxx avoid creation of gp_Dir2d with zero components.
---
 src/Bisector/Bisector_BisecCC.cxx |  3 ++-
 src/Bisector/Bisector_BisecPC.cxx | 37 +++++++++++++++++++------------
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/src/Bisector/Bisector_BisecCC.cxx b/src/Bisector/Bisector_BisecCC.cxx
index c8d9f1238a..71b380b727 100644
--- a/src/Bisector/Bisector_BisecCC.cxx
+++ b/src/Bisector/Bisector_BisecCC.cxx
@@ -684,12 +684,13 @@ gp_Pnt2d Bisector_BisecCC::ValueAndDist (const Standard_Real  U,
     gp_Vec2d P2P1(P1.X() - P2.X(),P1.Y() - P2.Y());
     Standard_Real SquareP2P1 = P2P1.SquareMagnitude();
     Standard_Real N1P2P1     = N1.Dot(P2P1);
+    const Standard_Real anEps = Epsilon(1);
 
     if (P1.IsEqual(P2,Precision::Confusion())) {
       PBis = P1 ;
       Dist = 0.0;
     }
-    else if (N1P2P1*sign1 < 0) {
+    else if (N1P2P1*sign1 < anEps) {
       Valid = Standard_False;
     }
     else {	
diff --git a/src/Bisector/Bisector_BisecPC.cxx b/src/Bisector/Bisector_BisecPC.cxx
index b577d8ad24..8abf8d972d 100644
--- a/src/Bisector/Bisector_BisecPC.cxx
+++ b/src/Bisector/Bisector_BisecPC.cxx
@@ -328,26 +328,35 @@ void Bisector_BisecPC::Extension(const Standard_Real    U,
 				       gp_Vec2d&        V2,
 				       gp_Vec2d&        V3 ) const
 {
-  gp_Dir2d      DirExt;
   Standard_Real dU;
 
+  V1.SetCoord(0., 0.);
+  V2.SetCoord(0., 0.);
+  V3.SetCoord(0., 0.);
   if      ( U < startIntervals.Value(bisInterval)) {
-    dU = U - startIntervals.Value(bisInterval);
-    DirExt.SetCoord(pointStartBis.X() - point.X(),
-		    pointStartBis.Y() - point.Y());
-    P.SetCoord(pointStartBis.X() + dU*DirExt.X(),
-	       pointStartBis.Y() + dU*DirExt.Y());
+    if (pointStartBis.IsEqual(point, Precision::PConfusion()))
+      P = pointStartBis;
+    else {
+      dU = U - startIntervals.Value(bisInterval);
+      gp_Dir2d DirExt(pointStartBis.X() - point.X(),
+                      pointStartBis.Y() - point.Y());
+      P.SetCoord(pointStartBis.X() + dU*DirExt.X(),
+                 pointStartBis.Y() + dU*DirExt.Y());
+      V1.SetCoord(DirExt.X(), DirExt.Y());
+    }
   }
   else if ( U > endIntervals.Value(bisInterval)) { 
-    dU =  U - endIntervals.Value(bisInterval);
-    DirExt.SetCoord(point.X() - pointEndBis.X(),
-		    point.Y() - pointEndBis.Y()); 
-    P.SetCoord(pointEndBis.X() + dU*DirExt.X(),
-	       pointEndBis.Y() + dU*DirExt.Y());
+    if (pointEndBis.IsEqual(point, Precision::PConfusion()))
+      P = pointEndBis;
+    else {
+      dU =  U - endIntervals.Value(bisInterval);
+      gp_Dir2d DirExt(point.X() - pointEndBis.X(),
+                      point.Y() - pointEndBis.Y()); 
+      P.SetCoord(pointEndBis.X() + dU*DirExt.X(),
+                 pointEndBis.Y() + dU*DirExt.Y());
+      V1.SetCoord(DirExt.X(), DirExt.Y());
+    }
   }
-  V1.SetCoord(DirExt.X(),DirExt.Y());
-  V2.SetCoord(0.        ,0.        );
-  V3.SetCoord(0.        ,0.        );
 }