diff --git a/CurveComposite.cpp b/CurveComposite.cpp
index d0fd1f4..73bdbb1 100644
--- a/CurveComposite.cpp
+++ b/CurveComposite.cpp
@@ -1913,6 +1913,12 @@ CurveComposite::TrimStartEndAtParam( double dUStartTrim, double dUEndTrim)
 bool
 CurveComposite::TrimStartAtLen( double dLenTrim)
 {
+  // verifico validità lunghezza risultante
+   if ( dLenTrim < EPS_ZERO)
+      return true ;
+   double dLen ;
+   if ( ! GetLength( dLen)  ||  ( dLen - dLenTrim) < EPS_SMALL)
+      return false ;
   // ciclo sulle diverse curve dall'inizio
    double dLenToTrim = dLenTrim ;
    for ( auto Iter = m_CrvSmplS.begin() ; Iter != m_CrvSmplS.end() ;) {
@@ -1959,6 +1965,14 @@ CurveComposite::TrimStartAtLen( double dLenTrim)
 bool
 CurveComposite::TrimEndAtLen( double dLenTrim)
 {
+  // verifico validità lunghezza risultante
+   if ( dLenTrim < EPS_SMALL)
+      return false ;
+   double dLen ;
+   if ( ! GetLength( dLen))
+      return false ;
+   if ( ( dLen - dLenTrim) < EPS_ZERO)
+      return true ;
   // ciclo sulle diverse curve dalla fine
    bool bToErase = false ;
    double dLenToTrim = dLenTrim ;
diff --git a/EgtGeomKernel.rc b/EgtGeomKernel.rc
index 400f3e8..b030fc0 100644
Binary files a/EgtGeomKernel.rc and b/EgtGeomKernel.rc differ