bug #1272: Disable assertion when total number of columns is zero.

Also moved assertion to finished() method and adapted unit-test

2 files changed, 12 insertions, 8 deletions

diff --git a/Eigen/src/Core/CommaInitializer.h b/Eigen/src/Core/CommaInitializer.h
index b39a661d0..d218e9814 100644
--- a/Eigen/src/Core/CommaInitializer.h
+++ b/Eigen/src/Core/CommaInitializer.h
@@ -103,9 +103,7 @@ struct CommaInitializer
   EIGEN_EXCEPTION_SPEC(Eigen::eigen_assert_exception)
 #endif
   {
-    eigen_assert((m_row+m_currentBlockRows) == m_xpr.rows()
-         && m_col == m_xpr.cols()
-         && "Too few coefficients passed to comma initializer (operator<<)");
+      finished();
   }
 
   /** \returns the built matrix once all its coefficients have been set.
@@ -116,7 +114,12 @@ struct CommaInitializer
     * \endcode
     */
   EIGEN_DEVICE_FUNC
-  inline XprType& finished() { return m_xpr; }
+  inline XprType& finished() {
+      eigen_assert(((m_row+m_currentBlockRows) == m_xpr.rows() || m_xpr.cols() == 0)
+           && m_col == m_xpr.cols()
+           && "Too few coefficients passed to comma initializer (operator<<)");
+      return m_xpr;
+  }
 
   XprType& m_xpr;           // target expression
   Index m_row;              // current row id
diff --git a/test/commainitializer.cpp b/test/commainitializer.cpp
index 5ece4f6cc..9844adbd2 100644
--- a/test/commainitializer.cpp
+++ b/test/commainitializer.cpp
@@ -23,11 +23,12 @@ void test_blocks()
 
   MatrixXi matx11 = mat11, matx12 = mat12, matx21 = mat21, matx22 = mat22;
 
-  // The only remaining border case is M1==M2>0 && N1==N2==0.
-  // In that case it is not possible to decide (without backtracking) if a block starts a new row or does not
-  if(M1 != M2 || M1 == 0 || N1>0 || N2>0)
   {
     VERIFY_IS_EQUAL((m_fixed << mat11, mat12, mat21, matx22).finished(), (m_dynamic << mat11, matx12, mat21, matx22).finished());
+    VERIFY_IS_EQUAL((m_fixed.template topLeftCorner<M1,N1>()), mat11);
+    VERIFY_IS_EQUAL((m_fixed.template topRightCorner<M1,N2>()), mat12);
+    VERIFY_IS_EQUAL((m_fixed.template bottomLeftCorner<M2,N1>()), mat21);
+    VERIFY_IS_EQUAL((m_fixed.template bottomRightCorner<M2,N2>()), mat22);
     VERIFY_IS_EQUAL((m_fixed << mat12, mat11, matx21, mat22).finished(), (m_dynamic << mat12, matx11, matx21, mat22).finished());
   }
 
@@ -36,7 +37,7 @@ void test_blocks()
     VERIFY_RAISES_ASSERT((m_fixed << mat11, mat12, mat11, mat21, mat22));
     VERIFY_RAISES_ASSERT((m_fixed << mat11, mat12, mat21, mat21, mat22));
   }
-  else if(N2 > 0 || M1 != M2) // border case if both sublocks have zero columns and same number of rows
+  else
   {
     // allow insertion of zero-column blocks:
     VERIFY_IS_EQUAL((m_fixed << mat11, mat12, mat11, mat11, mat21, mat21, mat22).finished(), (m_dynamic << mat12, mat22).finished());