From 5d28e519534b5bb6ca4e1d9ec5c14602a14575e8 Mon Sep 17 00:00:00 2001
From: Arnaud Giersch <arnaud.giersch@univ-fcomte.fr>
Date: Wed, 27 Feb 2019 21:49:32 +0100
Subject: [PATCH] Fix Backtrace::operator=.

---
 src/xbt/backtrace.cpp | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/xbt/backtrace.cpp b/src/xbt/backtrace.cpp
index b9f4009f05..600b7e8055 100644
--- a/src/xbt/backtrace.cpp
+++ b/src/xbt/backtrace.cpp
@@ -63,7 +63,12 @@ public:
   bool unref()
   {
     refcount_--;
-    return refcount_ == 0;
+    if (refcount_ == 0) {
+      delete this;
+      return true;
+    } else {
+      return false;
+    }
   }
 #if HAVE_BOOST_STACKTRACE
   boost::stacktrace::stacktrace st;
@@ -92,24 +97,31 @@ Backtrace::Backtrace(Backtrace&& bt)
 
 Backtrace& Backtrace::operator=(const Backtrace& rhs)
 {
-  impl_ = rhs.impl_;
-  if (impl_)
-    impl_->ref();
+  if (this != &rhs) {
+    if (impl_)
+      impl_->unref();
+    impl_ = rhs.impl_;
+    if (impl_)
+      impl_->ref();
+  }
   return *this;
 }
 
 Backtrace& Backtrace::operator=(Backtrace&& rhs)
 {
-  impl_     = rhs.impl_;
-  rhs.impl_ = nullptr;
+  if (this != &rhs) {
+    if (impl_)
+      impl_->unref();
+    impl_     = rhs.impl_;
+    rhs.impl_ = nullptr;
+  }
   return *this;
 }
 
 Backtrace::~Backtrace()
 {
-  if (impl_ != nullptr && impl_->unref()) {
-    delete impl_;
-  }
+  if (impl_)
+    impl_->unref();
 }
 
 std::string const Backtrace::resolve() const
-- 
2.20.1