diff --git a/ChangeLog b/ChangeLog
index 5691c5a8db..1247802360 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 1999-11-15  Lars Gullik Bjønnes  <larsbj@lyx.org>
 
+	* src/support/LSubstring.[Ch]: made the second arg of most of the
+	constructors be a const reference. 
+
+	* src/mathed/math_parser.C (LexInitCodes): small bug introduced by
+	me fixed.
+
+	* src/support/lyxstring.[Ch] (swap): added missing member function
+	and specialization of swap(str, str); 
+
 	* src/menus.C (ShowBufferMenu): to use the new BufferStorage
 
 	* src/bufferlist.[Ch]: use the new BufferStorage class and remove all
diff --git a/src/mathed/math_parser.C b/src/mathed/math_parser.C
index be49f67e1d..d8db81f1c1 100644
--- a/src/mathed/math_parser.C
+++ b/src/mathed/math_parser.C
@@ -119,7 +119,7 @@ static void LexInitCodes()
    lexcode['%'] = LexComment;
    lexcode['#'] = LexArgument;
    lexcode['+'] = lexcode['-'] = lexcode['*'] = lexcode['/'] = 
-   lexcode['<'] = lexcode['>'] = lexcode['= '] = LexBOP;
+   lexcode['<'] = lexcode['>'] = lexcode['='] = LexBOP;
    
    lexcode['!'] = lexcode[','] = lexcode[':'] = lexcode[';'] = LexMathSpace;
    lexcode['('] = lexcode[')'] = lexcode['|'] = lexcode['.'] = lexcode['?'] = LexOther; 
diff --git a/src/support/LSubstring.C b/src/support/LSubstring.C
index b2c2ef05de..6c5509fdad 100644
--- a/src/support/LSubstring.C
+++ b/src/support/LSubstring.C
@@ -21,14 +21,14 @@ LSubstring::LSubstring(string & s, size_type i, size_type l)
 }
 
 
-LSubstring::LSubstring(string & s, string & s2)
+LSubstring::LSubstring(string & s, string const & s2)
 	: ps(&s), n(s2.length())
 {
 	pos = s.find(s2);
 }
 
 
-LSubstring::LSubstring(string & s, char * p)
+LSubstring::LSubstring(string & s, string::value_type const * p)
 	: ps(&s)
 {
 	n = strlen(p);
@@ -36,7 +36,7 @@ LSubstring::LSubstring(string & s, char * p)
 }
 
 
-LSubstring::LSubstring(string & s, LRegex & r)
+LSubstring::LSubstring(string & s, LRegex const & r)
 	: ps(&s)
 {
 	LRegex::MatchPair res = r.first_match(s);
@@ -82,13 +82,3 @@ LSubstring::operator string() const
 {
 	return string(*ps, pos, n); // copy from *ps
 }
-
-
-#if 0
-LSubstring::operator char const * () const
-{
-	static string tr;
-	tr.assign(*ps, pos, n);
-	return tr.c_str();
-}
-#endif
diff --git a/src/support/LSubstring.h b/src/support/LSubstring.h
index 96164f11b9..f5ec98b8f9 100644
--- a/src/support/LSubstring.h
+++ b/src/support/LSubstring.h
@@ -31,11 +31,11 @@ public:
 	///
 	LSubstring(string & s, size_type i, size_type n);
 	///
-	LSubstring(string & s, string & s2);
+	LSubstring(string & s, string const & s2);
 	///
-	LSubstring(string & s, string::value_type * p);
+	LSubstring(string & s, string::value_type const * p);
 	///
-	LSubstring(string & s, LRegex & r);
+	LSubstring(string & s, LRegex const & r);
 	///
 	LSubstring & operator=(string const &);
 	///
@@ -46,10 +46,6 @@ public:
 	LSubstring & operator=(string::value_type);
 	///
 	operator string() const;
-#if 0
-	///
-	operator char const * () const;
-#endif
 private:
 	///
 	string * ps;
diff --git a/src/support/lyxstring.C b/src/support/lyxstring.C
index 129cd75746..1083669415 100644
--- a/src/support/lyxstring.C
+++ b/src/support/lyxstring.C
@@ -1345,6 +1345,15 @@ lyxstring & lyxstring::replace(iterator i, iterator i2,
 }
 
 
+void lyxstring::swap(lyxstring & str)
+{
+	if (rep == str.rep) return;
+	Srep * tmp = str.rep;
+	str.rep = rep;
+	rep = tmp;
+}
+
+
 lyxstring & lyxstring::erase(size_type i, size_type n)
 {
 	Assert(i <= rep->sz); // STD!
@@ -1667,6 +1676,13 @@ lyxstring operator+(lyxstring const & a, lyxstring::value_type b)
 	return tmp;
 }
 
+
+void swap(lyxstring & str1, lyxstring & str2)
+{
+	str1.swap(str2);
+}
+
+
 #include <iostream>
 
 istream & operator>>(istream & is, lyxstring & s)
diff --git a/src/support/lyxstring.h b/src/support/lyxstring.h
index 22e0b88cc3..f2cd44fbf3 100644
--- a/src/support/lyxstring.h
+++ b/src/support/lyxstring.h
@@ -449,6 +449,9 @@ public:
 	///
 	lyxstring & replace(iterator i, iterator i2, iterator j, iterator j2);
 
+	///
+	void swap(lyxstring & str);
+	
 	/// Erase n chars from position i.
 	lyxstring & erase(size_type i = 0, size_type n = npos);
 
@@ -599,6 +602,8 @@ lyxstring operator+(lyxstring::value_type a, lyxstring const & b);
 lyxstring operator+(lyxstring const & a, lyxstring::value_type const * b);
 lyxstring operator+(lyxstring const & a, lyxstring::value_type b);
 
+void swap(lyxstring & s1, lyxstring & s2);
+
 istream & operator>>(istream &, lyxstring &);
 ostream & operator<<(ostream &, lyxstring const &);
 istream & getline(istream &, lyxstring &, lyxstring::value_type delim = '\n');