Fix update of L-BFGS history buffers after they become full.

Previously there was an assignment dimension mismatch in the
history update; thus, over time, the history would contain
(only) replicated copies of the (max_num_corrections_ -1)-th
update and the most recent update.

Change-Id: I26203acf689686d41a5029c675ebbe001fe05d90

internal/ceres/low_rank_inverse_hessian.cc

diff --git a/internal/ceres/low_rank_inverse_hessian.cc b/internal/ceres/low_rank_inverse_hessian.cc
index 3fe113f..4fabd5b 100644
--- a/internal/ceres/low_rank_inverse_hessian.cc
+++ b/internal/ceres/low_rank_inverse_hessian.cc
@@ -58,16 +58,16 @@
     // TODO(sameeragarwal): This can be done more efficiently using
     // a circular buffer/indexing scheme, but for simplicity we will
     // do the expensive copy for now.
-    delta_x_history_.block(0, 0, num_parameters_, max_num_corrections_ - 2) =
+    delta_x_history_.block(0, 0, num_parameters_, max_num_corrections_ - 1) =
         delta_x_history_
         .block(0, 1, num_parameters_, max_num_corrections_ - 1);
 
     delta_gradient_history_
-        .block(0, 0, num_parameters_, max_num_corrections_ - 2) =
+        .block(0, 0, num_parameters_, max_num_corrections_ - 1) =
         delta_gradient_history_
         .block(0, 1, num_parameters_, max_num_corrections_ - 1);
 
-    delta_x_dot_delta_gradient_.head(num_corrections_ - 2) =
+    delta_x_dot_delta_gradient_.head(num_corrections_ - 1) =
         delta_x_dot_delta_gradient_.tail(num_corrections_ - 1);
   } else {
     ++num_corrections_;