3 files changed, 4 insertions, 3 deletions
diff --git a/qtools/qcstring.cpp b/qtools/qcstring.cpp
index e0e53e4..c3aad40 100644
--- a/qtools/qcstring.cpp
+++ b/qtools/qcstring.cpp
@@ -466,7 +466,7 @@ QCString QCString::simplifyWhiteSpace() const
 
 QCString &QCString::insert( uint index, const char *s )
 {   
-  int len = qstrlen(s);
+  int len = s ? qstrlen(s) : 0;
   if ( len == 0 )
     return *this;
   uint olen = length();
diff --git a/qtools/qcstring.h b/qtools/qcstring.h
index 8df3bfd..ef1189a 100644
--- a/qtools/qcstring.h
+++ b/qtools/qcstring.h
@@ -295,6 +295,7 @@ inline void QCString::duplicate( const char *str)
 
 inline QCString &QCString::duplicate( const char *str, int)
 {
+  if (m_data==str) return *this;
   if (m_data) free(m_data);
   duplicate(str);
   return *this;
diff --git a/qtools/scstring.cpp b/qtools/scstring.cpp
index 5632f57..4a02320 100644
--- a/qtools/scstring.cpp
+++ b/qtools/scstring.cpp
@@ -84,6 +84,7 @@ SCString::~SCString()
 
 SCString &SCString::assign( const char *str )
 {
+  if (m_data==str) return *this;
   if (m_data) free(m_data);
   duplicate(str);
   return *this;
@@ -562,8 +563,7 @@ SCString &SCString::replace( const QRegExp &rx, const char *str )
   QString d = QString::fromLatin1( m_data );
   QString r = QString::fromLatin1( str );
   d.replace( rx, r );
-  operator=( d.ascii() );
-  return *this;
+  return assign(d.ascii());
 }
 
 long  SCString::toLong( bool *ok ) const