Protected ArchiveFileItor::operator=() from self assignment and potential memory leak.

catalogue/ArchiveFileItor.cpp

@@ -59,8 +59,14 @@ ArchiveFileItor::~ArchiveFileItor() {
 // operator=
 //------------------------------------------------------------------------------
 ArchiveFileItor &ArchiveFileItor::operator=(ArchiveFileItor &&rhs) {
-  m_impl = rhs.m_impl;
-  rhs.m_impl = nullptr;
+  // Protect against self assignment
+  if(this != &rhs) {
+    // Avoid memory leak
+    delete m_impl;
+
+    m_impl = rhs.m_impl;
+    rhs.m_impl = nullptr;
+  }
   return *this;
 }