diff -uNr source.orig/geometry/solids/CSG/src/G4Tubs.cc source/geometry/solids/CSG/src/G4Tubs.cc
--- source.orig/geometry/solids/CSG/src/G4Tubs.cc	Thu Mar 22 00:01:24 2001
+++ source/geometry/solids/CSG/src/G4Tubs.cc	Fri Mar 23 22:57:20 2001
@@ -29,6 +29,8 @@
 // 31.10.00 V.Grichine, assign sr, sphi in Distance ToOut(p,v,...)
 // 28.11.00 V.Grichine, bug fixed in Inside(p)
 
+// 22.03.01 K.Hoshina, bug fixed in Inside(p)
+
 #include "G4Tubs.hh"
 
 #include "G4VoxelLimits.hh"
@@ -334,46 +336,40 @@
 {
   G4double r2,pPhi,tolRMin,tolRMax;
   EInside in = kOutside ;
-
+  
   if (fabs(p.z()) <= fDz - kCarTolerance*0.5)
-  {
-    r2 = p.x()*p.x() + p.y()*p.y() ;
-
-    if (fRMin) tolRMin = fRMin + kRadTolerance*0.5 ;
-    else       tolRMin = 0 ;
-
-	       tolRMax = fRMax - kRadTolerance*0.5 ;
-	    
+  {	    
+    r2      = p.x()*p.x() + p.y()*p.y() ;
+    tolRMax = fRMax - kRadTolerance*0.5 ;
+    if (fRMin){
+      tolRMin = fRMin + kRadTolerance*0.5 ;
+    } else {
+      tolRMin = 0. ;
+    }
+    
     if (r2 >= tolRMin*tolRMin && r2 <= tolRMax*tolRMax)
     {
-      if ( fDPhi == 2*M_PI || r2 == 0 )  in = kInside ;
+      if ( fDPhi == 2*M_PI || r2 == 0. ) 
+      {
+        in = kInside ;
+      }
       else
       {
-// Try inner tolerant phi boundaries (=>inside)
-// if not inside, try outer tolerant phi boundaries
-
-        pPhi = atan2(p.y(),p.x()) ;
-
-	if ( pPhi < 0 ) pPhi += 2*M_PI ; // 0<=pPhi<2pi
-
-	if ( fSPhi >= 0 )
-	{
-	  if ( pPhi >= fSPhi + kAngTolerance*0.5 &&
-               pPhi <= fSPhi + fDPhi-kAngTolerance*0.5 ) in = kInside ;
+        // Try inner tolerant phi boundaries (=>inside)
+        // if not inside, try outer tolerant phi boundaries
 
-	  else if ( pPhi >= fSPhi - kAngTolerance*0.5 &&
-		    pPhi <= fSPhi + fDPhi + kAngTolerance*0.5 ) in = kSurface ;
+        pPhi = atan2(p.y(),p.x()) - (fSPhi - kAngTolerance*0.5) ;
+	while(pPhi < 0.)       pPhi += 2*M_PI ; // 0<=pPhi<2pi
+	while(pPhi >= 2*M_PI)  pPhi -= 2*M_PI ; // 0<=pPhi<2pi
+	
+	if ( pPhi >= kAngTolerance && pPhi <= fDPhi) 
+	{		
+	  in = kInside ;
 	}
-	else
+	else if ( pPhi >= 0. &&  pPhi <= fDPhi + kAngTolerance ) 
 	{
-	  // if (pPhi < fSPhi + 2*M_PI) pPhi += 2*M_PI ;
-
-	  if ( pPhi >= fSPhi + 2*M_PI + kAngTolerance*0.5 &&
-	       pPhi <= fSPhi + fDPhi + 2*M_PI - kAngTolerance*0.5) in = kInside ;
-
-	  else if (pPhi >= fSPhi+2*M_PI-kAngTolerance*0.5 &&
-		   pPhi <= fSPhi+fDPhi+2*M_PI+kAngTolerance*0.5) in = kSurface ;
-	}			    			    
+	  in = kSurface ;
+	}
       }
     }
     else  // Try generous boundaries
@@ -381,68 +377,53 @@
       tolRMin = fRMin - kRadTolerance*0.5 ;
       tolRMax = fRMax + kRadTolerance*0.5 ;
 
-      if ( tolRMin < 0 ) tolRMin = 0 ;
+      if ( tolRMin < 0. ) tolRMin = 0. ;
 
       if (r2 >= tolRMin*tolRMin && r2 <= tolRMax*tolRMax)
       {
-	if ( fDPhi == 2*M_PI || r2 == 0 ) // Continuous in phi or on z-axis
+	if ( fDPhi == 2*M_PI || r2 == 0. ) // Continuous in phi or on z-axis
 	{
 	    in = kSurface ;
 	}
 	else // Try outer tolerant phi boundaries only
 	{
-	  pPhi = atan2(p.y(),p.x()) ;
-
-	  if ( pPhi < 0 ) pPhi += 2*M_PI ; // 0<=pPhi<2pi
+	  pPhi = atan2(p.y(),p.x()) - (fSPhi - kAngTolerance*0.5) ;
+	  while(pPhi < 0.)       pPhi += 2*M_PI ; 	// 0<=pPhi<2pi
+	  while(pPhi >= 2*M_PI)  pPhi -= 2*M_PI ; 	// 0<=pPhi<2pi
 
-	  if ( fSPhi >= 0 )
-	  {
-	    if (pPhi >= fSPhi-kAngTolerance*0.5 &&
-		  pPhi <= fSPhi+fDPhi+kAngTolerance*0.5) in = kSurface ;	
-	  }
-	  else
-	  {
-	    //  if (pPhi < fSPhi + 2*M_PI ) pPhi += 2*M_PI ;
-
-	    if (pPhi >= fSPhi+2*M_PI-kAngTolerance*0.5 &&
-		pPhi <= fSPhi+fDPhi+2*M_PI+kAngTolerance*0.5) in=kSurface;
+	  if ( pPhi >= 0. && pPhi <= fDPhi+kAngTolerance) 
+	  {		
+	    in = kSurface ;
 	  }
 	}
       }
     }
   }
-  else if (fabs(p.z()) <= fDz+kCarTolerance*0.5) // Check within tolerant r limits
+  else if (fabs(p.z()) <= fDz+kCarTolerance*0.5) // Check within tolerant z limits
   {
     r2      = p.x()*p.x() + p.y()*p.y() ;
     tolRMin = fRMin - kRadTolerance*0.5 ;
     tolRMax = fRMax + kRadTolerance*0.5 ;
 
-    if ( tolRMin < 0 ) tolRMin = 0 ;
+    if ( tolRMin < 0. ) tolRMin = 0. ;
 
     if ( r2 >= tolRMin*tolRMin && r2 <= tolRMax*tolRMax )
     {
-      if (fDPhi == 2*M_PI || r2 == 0 ) // Continuous in phi or on z-axis
+      if (fDPhi == 2*M_PI || r2 == 0. ) // Continuous in phi or on z-axis
       {
 	in = kSurface ;
       }
       else // Try outer tolerant phi boundaries
       {
-	pPhi = atan2(p.y(),p.x()) ;
+	pPhi = atan2(p.y(),p.x()) - (fSPhi - kAngTolerance*0.5) ;
 
-	if ( pPhi < 0 ) pPhi += 2*M_PI ;		// 0<=pPhi<2pi
+	while(pPhi < 0.)      pPhi += 2*M_PI ; 	// 0<=pPhi<2pi
+	while(pPhi >= 2*M_PI) pPhi -= 2*M_PI ; 	// 0<=pPhi<2pi
 
-	if ( fSPhi >= 0 )
-	{
-	  if (pPhi >= fSPhi-kAngTolerance*0.5 &&
-	      pPhi <= fSPhi+fDPhi+kAngTolerance*0.5) in=kSurface; 	
+	if ( pPhi >= 0. && pPhi <= fDPhi + kAngTolerance) 
+	{		
+	  in = kSurface ;
 	}
-	else
-	{
-	  if ( pPhi < fSPhi + 2*M_PI ) pPhi += 2*M_PI ;
-
-	  if ( pPhi >= fSPhi+2*M_PI-kAngTolerance*0.5 &&
-	       pPhi <= fSPhi+fDPhi+2*M_PI+kAngTolerance*0.5) in = kSurface ;
-	}	    
       }
     }
   }