let eigen2 tests use the same ei_add_test macro, which required to prefix them with eigen2_ ; rename buildtests_eigen2 to eigen2_buildtests, etc.

test/eigen2/eigen2_bug_132.cpp

@@ -0,0 +1,41 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2010 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#include "main.h"
+
+void test_eigen2_bug_132() {
+  enum { size = 100 };
+  MatrixXd A(size, size);
+  VectorXd b(size), c(size);
+  {
+    VectorXd y = A.transpose() * (b-c);  // bug 132: infinite recursion in coeffRef
+    VectorXd z = (b-c).transpose() * A;  // bug 132: infinite recursion in coeffRef
+  }
+
+  // the following ones weren't failing, but let's include them for completeness:
+  {
+    VectorXd y = A * (b-c);
+    VectorXd z = (b-c).transpose() * A.transpose();
+  }
+}