Fix user iteration callbacks.

User callbacks got broken at some point due to the extra
layer of copying from Solver::Options to Minimizer::Options.
This copies the user callbacks when initializing
Minimizer::Options from Solver::Options, and adds a test to
this effect.

This also fixes a bug where the state updating callback was
not called before the user callbacks. This also adds a test
to solver_impl_test to ensure the state updating callbacks
work as expected.

Thanks to Luis Alberto Zarrabeitia for the report.

Issue: 46
Change-Id: I2b36415c89dafaa5c84ecaa727a325df122e1092
diff --git a/internal/ceres/minimizer_test.cc b/internal/ceres/minimizer_test.cc
new file mode 100644
index 0000000..1058036
--- /dev/null
+++ b/internal/ceres/minimizer_test.cc
@@ -0,0 +1,63 @@
+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2012 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+//   this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors may be
+//   used to endorse or promote products derived from this software without
+//   specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: keir@google.com (Keir Mierle)
+
+#include "gtest/gtest.h"
+#include "ceres/iteration_callback.h"
+#include "ceres/minimizer.h"
+#include "ceres/solver.h"
+
+namespace ceres {
+namespace internal {
+
+class FakeIterationCallback : public IterationCallback {
+ public:
+  virtual ~FakeIterationCallback() {}
+  virtual CallbackReturnType operator()(const IterationSummary& summary) {
+    return SOLVER_CONTINUE;
+  }
+};
+
+TEST(MinimizerTest, InitializationCopiesCallbacks) {
+  FakeIterationCallback callback0;
+  FakeIterationCallback callback1;
+
+  Solver::Options solver_options;
+  solver_options.callbacks.push_back(&callback0);
+  solver_options.callbacks.push_back(&callback1);
+
+  Minimizer::Options minimizer_options(solver_options);
+  ASSERT_EQ(2, minimizer_options.callbacks.size());
+
+  EXPECT_EQ(minimizer_options.callbacks[0], &callback0);
+  EXPECT_EQ(minimizer_options.callbacks[1], &callback1);
+}
+
+}  // namespace internal
+}  // namespace ceres