diff --git a/applications/test/CompactListList/CompactListListTest.C b/applications/test/CompactListList/CompactListListTest.C
index 136b5f4583..bdc043814b 100644
--- a/applications/test/CompactListList/CompactListListTest.C
+++ b/applications/test/CompactListList/CompactListListTest.C
@@ -32,6 +32,8 @@ Description
 
 #include "CompactListList.H"
 #include "IOstreams.H"
+#include "OStringStream.H"
+#include "IStringStream.H"
 
 using namespace Foam;
 
@@ -40,7 +42,29 @@ using namespace Foam;
 
 int main(int argc, char *argv[])
 {
-    CompactListList<label> cll1;
+    {
+        // null construct
+        CompactListList<label> cll1;
+        Info<< "cll1:" << cll1 << endl;
+
+        // Resize and assign row by row
+        labelList row0(2, 0);
+        labelList row1(3, 1);
+
+        labelList rowSizes(2);
+        rowSizes[0] = row0.size();
+        rowSizes[1] = row1.size();
+        cll1.resize(rowSizes);
+
+        cll1[0].assign(row0);   //note: operator= will not work since UList
+        cll1[1].assign(row1);
+        Info<< "cll1:" << cll1 << endl;
+
+        forAll(cll1.m(), i)
+        {
+            Info<< "i:" << i << " whichRow:" << cll1.whichRow(i) << endl;
+        }
+    }
 
     List<List<label> > lll(5);
     lll[0].setSize(3, 0);
@@ -60,14 +84,21 @@ int main(int argc, char *argv[])
 
     Info<< endl;
 
+    Info<< "cll2(2, 3) = " << cll2(2, 3) << nl << endl;
+    cll2(2, 3) = 999;
     Info<< "cll2(2, 3) = " << cll2(2, 3) << nl << endl;
 
-    Info<< "cll2 as List<List<label > > " << List<List<label > >(cll2) << endl;
+    Info<< "cll2 as List<List<label > > " << cll2()
+        << endl;
 
     cll2.setSize(3);
 
     Info<< "cll2  = " << cll2 << endl;
 
+    cll2.setSize(0);
+
+    Info<< "cll2  = " << cll2 << endl;
+
 
     List<label> rowSizes(5);
     rowSizes[0] = 2;
@@ -87,6 +118,27 @@ int main(int argc, char *argv[])
     Info<< "cll3 = " << cll3 << endl;
     Info<< "cll4 = " << cll4 << endl;
 
+
+    {
+        // IO
+        OStringStream ostr;
+        ostr << cll4;
+
+        IStringStream istr(ostr.str());
+        CompactListList<label> cll5(istr);
+        Info<< "cll5 = " << cll5 << endl;
+    }
+    {
+        // IO
+        cll4.clear();
+        OStringStream ostr;
+        ostr << cll4;
+
+        IStringStream istr(ostr.str());
+        CompactListList<label> cll5(istr);
+        Info<< "cll5 = " << cll5 << endl;
+    }
+
     return 0;
 }
 
diff --git a/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.C b/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.C
index 8e802fe48e..0ce02f7e81 100644
--- a/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.C
+++ b/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.C
@@ -31,13 +31,15 @@ License
 template<class T>
 Foam::CompactListList<T>::CompactListList(const List<List<T> >& ll)
 :
-    offsets_(ll.size())
+    size_(ll.size()),
+    offsets_(ll.size()+1)
 {
     label sumSize = 0;
+    offsets_[0] = 0;
     forAll(ll, i)
     {
         sumSize += ll[i].size();
-        offsets_[i] = sumSize;
+        offsets_[i+1] = sumSize;
     }
 
     m_.setSize(sumSize);
@@ -61,13 +63,15 @@ Foam::CompactListList<T>::CompactListList
     const UList<label>& rowSizes
 )
 :
-    offsets_(rowSizes.size())
+    size_(rowSizes.size()),
+    offsets_(rowSizes.size()+1)
 {
     label sumSize = 0;
+    offsets_[0] = 0;
     forAll(rowSizes, i)
     {
         sumSize += rowSizes[i];
-        offsets_[i] = sumSize;
+        offsets_[i+1] = sumSize;
     }
 
     m_.setSize(sumSize);
@@ -81,13 +85,15 @@ Foam::CompactListList<T>::CompactListList
     const T& t
 )
 :
-    offsets_(rowSizes.size())
+    size_(rowSizes.size()),
+    offsets_(rowSizes.size()+1)
 {
     label sumSize = 0;
+    offsets_[0] = 0;
     forAll(rowSizes, i)
     {
         sumSize += rowSizes[i];
-        offsets_[i] = sumSize;
+        offsets_[i+1] = sumSize;
     }
 
     m_.setSize(sumSize, t);
@@ -111,6 +117,7 @@ Foam::CompactListList<T>::CompactListList
     bool reUse
 )
 :
+    size_(lst.size()),
     offsets_(lst.offsets_, reUse),
     m_(lst.m_, reUse)
 {}
@@ -125,12 +132,13 @@ void Foam::CompactListList<T>::setSize(const label nRows)
     {
         clear();
     }
-    if (nRows < offsets_.size())
+    if (nRows < size())
     {
-        offsets_.setSize(nRows);
-        m_.setSize(offsets_[nRows - 1]);
+        size_ = nRows;
+        offsets_.setSize(nRows+1);
+        m_.setSize(offsets_[nRows]);
     }
-    else if (nRows > offsets_.size())
+    else if (nRows > size())
     {
         FatalErrorIn("CompactListList<T>::setSize(const label nRows)")
             << "Cannot be used to extend the list from " << offsets_.size()
@@ -148,7 +156,8 @@ void Foam::CompactListList<T>::setSize
     const label nData
 )
 {
-    offsets_.setSize(nRows);
+    size_ = nRows;
+    offsets_.setSize(nRows+1);
     m_.setSize(nData);
 }
 
@@ -161,7 +170,8 @@ void Foam::CompactListList<T>::setSize
     const T& t
 )
 {
-    offsets_.setSize(nRows);
+    size_ = nRows;
+    offsets_.setSize(nRows+1);
     m_.setSize(nData, t);
 }
 
@@ -169,13 +179,15 @@ void Foam::CompactListList<T>::setSize
 template<class T>
 void Foam::CompactListList<T>::setSize(const UList<label>& rowSizes)
 {
-    offsets_.setSize(rowSizes.size());
+    size_ = rowSizes.size();
+    offsets_.setSize(rowSizes.size()+1);
 
     label sumSize = 0;
+    offsets_[0] = 0;
     forAll(rowSizes, i)
     {
         sumSize += rowSizes[i];
-        offsets_[i] = sumSize;
+        offsets_[i+1] = sumSize;
     }
 
     m_.setSize(sumSize);
@@ -185,13 +197,14 @@ void Foam::CompactListList<T>::setSize(const UList<label>& rowSizes)
 template<class T>
 Foam::labelList Foam::CompactListList<T>::sizes() const
 {
-    labelList rowSizes(offsets_.size());
+    labelList rowSizes(size());
 
-    label prevOffset = 0;
-    forAll(offsets_, i)
+    if (rowSizes.size() > 0)
     {
-        rowSizes[i] = offsets_[i]-prevOffset;
-        prevOffset = offsets_[i];
+        forAll(rowSizes, i)
+        {
+            rowSizes[i] = offsets_[i+1] - offsets_[i];
+        }
     }
     return rowSizes;
 }
@@ -200,6 +213,7 @@ Foam::labelList Foam::CompactListList<T>::sizes() const
 template<class T>
 void Foam::CompactListList<T>::clear()
 {
+    size_ = 0;
     offsets_.clear();
     m_.clear();
 }
@@ -208,6 +222,7 @@ void Foam::CompactListList<T>::clear()
 template<class T>
 void Foam::CompactListList<T>::transfer(CompactListList<T>& a)
 {
+    size_ = a.size_;
     offsets_.transfer(a.offsets_);
     m_.transfer(a.m_);
 }
@@ -218,21 +233,11 @@ void Foam::CompactListList<T>::transfer(CompactListList<T>& a)
 template<class T>
 Foam::List<Foam::List<T> > Foam::CompactListList<T>::operator()() const
 {
-    List<List<T> > ll(offsets_.size());
+    List<List<T> > ll(size());
 
-    label offsetPrev = 0;
-    forAll(offsets_, i)
+    forAll(ll, i)
     {
-        List<T>& lst = ll[i];
-
-        lst.setSize(offsets_[i] - offsetPrev);
-
-        forAll(lst, j)
-        {
-            lst[j] = m_[offsetPrev + j];
-        }
-
-        offsetPrev = offsets_[i];
+        ll[i] = operator[](i);
     }
 
     return ll;
diff --git a/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H b/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H
index f0a80cc1bd..bccb31b79d 100644
--- a/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H
+++ b/src/OpenFOAM/containers/Lists/CompactListList/CompactListList.H
@@ -29,15 +29,17 @@ Description
     A packed storage unstructured matrix of objects of type \<T\>
     using an offset table for access.
 
-    The offset table is the size of the number of rows whose elements are the
+    The offset table is the size of the number of rows+1
+    whose elements are the
     accumulated sizes of the rows, i.e.
-      - offset[i] gives the index of first element of row i + 1
-      - offset[i] - offset[i-1] is the number of elements in row i
-
-    and for i = 0, offset[i-1] = 0.
+      - offset[i] gives the index of first element of row i
+      - offset[i+1] - offset[i] is the number of elements in row i
 
     Storage is allocated on free-store during construction.
 
+    As a special case a null-contructed CompactListList has an empty
+    offsets_ (instead of size 1).
+
 SourceFiles
     CompactListList.C
     CompactListListI.H
@@ -72,6 +74,8 @@ class CompactListList
 {
     // Private data
 
+        label size_;
+
         //- Offset table
         List<label> offsets_;
 
@@ -92,7 +96,7 @@ public:
         inline CompactListList();
 
         //- Construct by converting given List<List<T> >
-        CompactListList(const List<List<T> >&);
+        explicit CompactListList(const List<List<T> >&);
 
         //- Construct given size of offset table (number of rows)
         //  and number of data.
@@ -103,13 +107,13 @@ public:
         inline CompactListList(const label nRows, const label nData, const T&);
 
         //- Construct given list of row-sizes.
-        CompactListList(const UList<label>& rowSizes);
+        explicit CompactListList(const UList<label>& rowSizes);
 
         //- Construct given list of row-sizes
         CompactListList(const UList<label>& rowSizes, const T&);
 
         //- Construct by transferring the parameter contents
-        CompactListList(const Xfer<CompactListList<T> >&);
+        explicit CompactListList(const Xfer<CompactListList<T> >&);
 
         //- Construct as copy or re-use as specified.
         CompactListList(CompactListList<T>&, bool reUse);
@@ -131,7 +135,7 @@ public:
             //- Return true if the number of rows is zero
             inline bool empty() const;
 
-            //- Return the offset table
+            //- Return the offset table (= size()+1)
             inline const List<label>& offsets() const;
 
             //- Return non-const access to the offset table
diff --git a/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H b/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H
index dc57627911..e0fb0187d2 100644
--- a/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H
+++ b/src/OpenFOAM/containers/Lists/CompactListList/CompactListListI.H
@@ -24,11 +24,15 @@ License
 
 \*---------------------------------------------------------------------------*/
 
+#include "ListOps.H"
+#include "SubList.H"
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 template<class T>
 inline Foam::CompactListList<T>::CompactListList()
+:
+    size_(0)
 {}
 
 
@@ -39,7 +43,8 @@ inline Foam::CompactListList<T>::CompactListList
     const label nData
 )
 :
-    offsets_(nRows, 0),
+    size_(nRows),
+    offsets_(nRows+1, 0),
     m_(nData)
 {}
 
@@ -52,7 +57,8 @@ inline Foam::CompactListList<T>::CompactListList
     const T& t
 )
 :
-    offsets_(nRows, 0),
+    size_(nRows),
+    offsets_(nRows+1, 0),
     m_(nData, t)
 {}
 
@@ -77,14 +83,14 @@ inline const Foam::CompactListList<T>& Foam::CompactListList<T>::null()
 template<class T>
 inline Foam::label Foam::CompactListList<T>::size() const
 {
-    return offsets_.size();
+    return size_;
 }
 
 
 template<class T>
 inline bool Foam::CompactListList<T>::empty() const
 {
-    return offsets_.empty();
+    return !size_;
 }
 
 
@@ -123,14 +129,7 @@ inline Foam::label Foam::CompactListList<T>::index
     const label j
 ) const
 {
-    if (i == 0)
-    {
-        return j;
-    }
-    else
-    {
-        return offsets_[i-1] + j;
-    }
+    return offsets_[i] + j;
 }
 
 
@@ -146,15 +145,7 @@ inline Foam::label Foam::CompactListList<T>::whichRow(const label i) const
             << abort(FatalError);
     }
 
-    forAll(offsets_, rowI)
-    {
-        if (i < offsets_[rowI])
-        {
-            return rowI;
-        }
-    }
-
-    return -1;
+    return findLower(offsets_, i+1);
 }
 
 
@@ -221,14 +212,9 @@ inline Foam::UList<T> Foam::CompactListList<T>::operator[]
     const label i
 )
 {
-    if (i == 0)
-    {
-        return UList<T>(m_.begin(), offsets_[i]);
-    }
-    else
-    {
-        return UList<T>(&m_[offsets_[i-1]], offsets_[i] - offsets_[i-1]);
-    }
+    //return SubList<T>(m_, offsets_[i+1]-start, start);
+    label start = offsets_[i];
+    return UList<T>(&m_[start], offsets_[i+1] - start);
 }
 
 
@@ -238,14 +224,9 @@ inline const Foam::UList<T> Foam::CompactListList<T>::operator[]
     const label i
 ) const
 {
-    if (i == 0)
-    {
-        return UList<T>(m_.begin(), offsets_[i]);
-    }
-    else
-    {
-        return UList<T>(&m_[offsets_[i-1]], offsets_[i] - offsets_[i-1]);
-    }
+    label start = offsets_[i];
+    //return SubList<T>(m_, offsets_[i+1]-start, start);
+    return UList<T>(const_cast<T*>(&m_[start]), offsets_[i+1] - start);
 }
 
 
diff --git a/src/OpenFOAM/containers/Lists/CompactListList/CompactListListIO.C b/src/OpenFOAM/containers/Lists/CompactListList/CompactListListIO.C
index 0360e60ee6..0429b2976c 100644
--- a/src/OpenFOAM/containers/Lists/CompactListList/CompactListListIO.C
+++ b/src/OpenFOAM/containers/Lists/CompactListList/CompactListListIO.C
@@ -42,6 +42,15 @@ template<class T>
 Foam::Istream& Foam::operator>>(Istream& is, CompactListList<T>& lst)
 {
     is  >> lst.offsets_ >> lst.m_;
+    // Note: empty list gets output as two empty lists
+    if (lst.offsets_.size() == 0)
+    {
+        lst.size_ = 0;
+    }
+    else
+    {
+        lst.size_ = lst.offsets_.size()-1;
+    }
     return is;
 }