From 75dbe4afde19fe1b9c82f1486e19e7679c8ad665 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Villemot?= <sebastien@dynare.org>
Date: Thu, 10 Apr 2014 11:43:26 +0200
Subject: [PATCH] Bugfix: M_.sigma_e_is_diagonal could be wrong if there were
 several shocks blocks.

---
 ModFile.cc | 3 +++
 Shocks.cc  | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/ModFile.cc b/ModFile.cc
index 27299dea..649440c9 100644
--- a/ModFile.cc
+++ b/ModFile.cc
@@ -594,6 +594,9 @@ ModFile::writeOutputFiles(const string &basename, bool clear_all, bool no_log, b
     mOutputFile << "M_.H = 0;" << endl
                 << "M_.Correlation_matrix_ME = 1;" << endl;
 
+  // May be later modified by a shocks block
+  mOutputFile << "M_.sigma_e_is_diagonal = 1;" << endl;
+
   // Initialize M_.det_shocks
   mOutputFile << "M_.det_shocks = [];" << endl;
 
diff --git a/Shocks.cc b/Shocks.cc
index 25adbdee..8373d9d9 100644
--- a/Shocks.cc
+++ b/Shocks.cc
@@ -89,9 +89,14 @@ ShocksStatement::writeOutput(ostream &output, const string &basename) const
   writeDetShocks(output);
   writeVarAndStdShocks(output);
   writeCovarAndCorrShocks(output);
+
+  /* M_.sigma_e_is_diagonal is initialized to 1 by ModFile.cc.
+     If there are no off-diagonal elements, and we are not in overwrite mode,
+     then we don't reset it to 1, since there might be previous shocks blocks
+     with off-diagonal elements. */
   if (covar_shocks.size()+corr_shocks.size() > 0)
     output << "M_.sigma_e_is_diagonal = 0;" << endl;
-  else
+  else if (overwrite)
     output << "M_.sigma_e_is_diagonal = 1;" << endl;
 }