The following files have issues with conversion of signed char to int 
when used with islower, isupper, tolower, and toupper.

       gssftp/cmds.c has "char *tp" cast to (int)
       telnet/telnet/telnet.c has "char c" cast to (int)
       lib/kadm5/srv/server_misc.c has "char c" cast to (int)
       lib/kadm5/srv/server_acl.c has "char *op" cast to (int)
       lib/krb5/os/hst_realm.c has "char c" and "char *cp" cast to (int)
       lib/krb4/kparse.c has "char *q" cast to (int)
       lib/krb5/krb/conv_princ.c has "char *cp" cast to (int)
       lib/krb5/os/sn2princ.c has "register char *cp" cast to (int)

Jeffrey Altman