diff --git a/CHANGES.current b/CHANGES.current
index edef80385..91ece6ac0 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -1,6 +1,10 @@
 Version 1.3.35 (in progress)
 ============================
 
+03/17/2008: olly
+	    Fix memory leak in SWIG's parser (based on patch from Russell
+	    Bryant in SF#1914023).`
+
 03/12/2008: wsfulton
             Fix bug #1878285 - unnecessary cast for C struct creation wrappers.
 
diff --git a/Source/Preprocessor/expr.c b/Source/Preprocessor/expr.c
index 6113851b9..4da24a774 100644
--- a/Source/Preprocessor/expr.c
+++ b/Source/Preprocessor/expr.c
@@ -226,7 +226,6 @@ void Preprocessor_expr_init(void) {
 }
 
 void Preprocessor_expr_delete(void) {
-  Scanner_clear(scan);
   DelScanner(scan);
 }
 
diff --git a/Source/Swig/scanner.c b/Source/Swig/scanner.c
index bb2181e70..e8b1b5f46 100644
--- a/Source/Swig/scanner.c
+++ b/Source/Swig/scanner.c
@@ -44,7 +44,7 @@ Scanner *NewScanner() {
   s->nexttoken = -1;
   s->start_line = 1;
   s->yylen = 0;
-  s->idstart = "";
+  s->idstart = NULL;
   s->scanobjs = NewList();
   s->text = NewStringEmpty();
   s->str = 0;
@@ -66,6 +66,7 @@ void DelScanner(Scanner * s) {
   Delete(s->file);
   Delete(s->error);
   Delete(s->str);
+  free(s->idstart);
   free(s);
 }
 
@@ -170,7 +171,8 @@ int Scanner_start_line(Scanner * s) {
  * Change the set of additional characters that can be used to start an identifier.
  * ----------------------------------------------------------------------------- */
 
-void Scanner_idstart(Scanner * s, char *id) {
+void Scanner_idstart(Scanner * s, const char *id) {
+  free(s->idstart);
   s->idstart = Swig_copy_string(id);
 }
 
@@ -421,7 +423,8 @@ static int look(Scanner * s) {
 
       /* Look for possible identifiers */
 
-      else if ((isalpha(c)) || (c == '_') || (strchr(s->idstart, c)))
+      else if ((isalpha(c)) || (c == '_') ||
+	       (s->idstart && strchr(s->idstart, c)))
 	state = 7;
 
       /* Look for single character symbols */
@@ -640,7 +643,8 @@ static int look(Scanner * s) {
 	Setline(s->text, Getline(s->str));
 	Setfile(s->text, Getfile(s->str));
 	s->start_line = s->line;
-      } else if (strchr(s->idstart, '%') && ((isalpha(c)) || (c == '_'))) {
+      } else if (s->idstart && strchr(s->idstart, '%') &&
+	         ((isalpha(c)) || (c == '_'))) {
 	state = 7;
       } else if (c == '=') {
 	return SWIG_TOKEN_MODEQUAL;
diff --git a/Source/Swig/swigscan.h b/Source/Swig/swigscan.h
index 88ce95636..2486286a9 100644
--- a/Source/Swig/swigscan.h
+++ b/Source/Swig/swigscan.h
@@ -24,7 +24,7 @@ extern void         Scanner_set_location(Scanner *, String *file, int line);
 extern String      *Scanner_file(Scanner *);
 extern int          Scanner_line(Scanner *);
 extern int          Scanner_start_line(Scanner *);
-extern void         Scanner_idstart(Scanner *, char *idchar);
+extern void         Scanner_idstart(Scanner *, const char *idchar);
 extern String      *Scanner_errmsg(Scanner *);
 extern int          Scanner_errline(Scanner *);
 extern int          Scanner_isoperator(int tokval);