bugfix for a = a * b; when a has to be resized

1 files changed, 19 insertions, 2 deletions

diff --git a/Eigen/src/Core/Matrix.h b/Eigen/src/Core/Matrix.h
index 5301f4849..32b526ef3 100644
--- a/Eigen/src/Core/Matrix.h
+++ b/Eigen/src/Core/Matrix.h
@@ -536,6 +536,9 @@ class Matrix
       resizeLike(other);
     }
 
+    template<typename MatrixType, typename OtherDerived, bool EvalBeforeAssigning = (int(OtherDerived::Flags) & EvalBeforeAssigningBit) != 0>
+    struct ei_matrix_set_selector;
+
     /** \internal Copies the value of the expression \a other into \c *this with automatic resizing.
       *
       * *this might be resized to match the dimensions of \a other. If *this was a null matrix (not already initialized),
@@ -550,8 +553,8 @@ class Matrix
     template<typename OtherDerived>
     EIGEN_STRONG_INLINE Matrix& _set(const MatrixBase<OtherDerived>& other)
     {
-      _resize_to_match(other);
-      return Base::operator=(other);
+      ei_matrix_set_selector<Matrix,OtherDerived>::run(*this,other.derived());
+      return *this;
     }
 
     /** \internal Like _set() but additionally makes the assumption that no aliasing effect can happen (which
@@ -600,6 +603,20 @@ class Matrix
     }
 };
 
+template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
+template<typename MatrixType, typename OtherDerived>
+struct Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols>::ei_matrix_set_selector<MatrixType,OtherDerived,true>
+{
+  static void run(MatrixType& dst, const OtherDerived& src) { dst._set_noalias(src.eval()); }
+};
+
+template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
+template<typename MatrixType, typename OtherDerived>
+struct Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols>::ei_matrix_set_selector<MatrixType,OtherDerived,false>
+{
+  static void run(MatrixType& dst, const OtherDerived& src) { dst._set_noalias(src); }
+};
+
 /** \defgroup matrixtypedefs Global matrix typedefs
   *
   * \ingroup Core_Module