diff -U 3 -H -d -r -N -- doxygen-1.6.0/src/util.cpp doxygen-1.6.0-warnings/src/util.cpp
--- doxygen-1.6.0/src/util.cpp	2009-08-20 14:13:51.000000000 +0200
+++ doxygen-1.6.0-warnings/src/util.cpp	2009-08-21 15:07:16.000000000 +0200
@@ -4760,9 +4760,9 @@
 {
   static bool caseSenseNames = Config_getBool("CASE_SENSE_NAMES");
   QCString result;
-  char c;
+  unsigned char c;
   const char *p=name;
-  while ((c=*p++)!=0)
+  while ((c=(unsigned char)*p++)!=0)
   {
     switch(c)
     {
@@ -4789,11 +4789,11 @@
       case '+': result+="_09"; break;
       case '=': result+="_0A"; break;
       default: 
-                if (c<0)
+                if (c>0x7f)
                 {
                   static char map[] = "0123456789ABCDEF";
                   char ids[5];
-                  unsigned char id = (unsigned char)c;
+                  unsigned char id = c;
                   ids[0]='_';
                   ids[1]='x';
                   ids[2]=map[id>>4];