From 3bc57780aaa53889efdbc9751c6ada3ece515160 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Atgeirr=20Fl=C3=B8=20Rasmussen?= <atgeirr@sintef.no>
Date: Wed, 26 Mar 2014 11:44:49 +0100
Subject: [PATCH] Fix bug in -= operator.

---
 opm/autodiff/AutoDiffBlock.hpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/opm/autodiff/AutoDiffBlock.hpp b/opm/autodiff/AutoDiffBlock.hpp
index a98c014be..7255b8dd1 100644
--- a/opm/autodiff/AutoDiffBlock.hpp
+++ b/opm/autodiff/AutoDiffBlock.hpp
@@ -198,7 +198,11 @@ namespace Opm
         AutoDiffBlock& operator-=(const AutoDiffBlock& rhs)
         {
             if (jac_.empty()) {
-                jac_ = rhs.jac_;
+                const int num_blocks = rhs.numBlocks();
+                jac_.resize(num_blocks);
+                for (int block = 0; block < num_blocks; ++block) {
+                    jac_[block] = -rhs.jac_[block];
+                }
             } else if (!rhs.jac_.empty()) {
                 assert (numBlocks()    == rhs.numBlocks());
                 assert (value().size() == rhs.value().size());