*** ./main.c.ORIG	Thu Aug 25 09:38:09 2011
--- ./main.c	Thu Aug 25 09:39:27 2011
***************
*** 3162,3167 ****
--- 3162,3207 ----
  #define USE_NO_DEV_TTY 0
  #endif
  
+ 
+ /***************************************************************************
+                                  unsetenv()
+  ****************************************************************************/
+ 
+ #ifdef _AIX51
+ int
+ unsetenv( const char *name )
+ {
+   size_t len;
+   char **ep;
+ 
+   if ((name == NULL) || (*name == '\0') || (strchr( name, '=' ) != NULL))
+   {
+     errno = EINVAL;
+     return( -1 );
+   }
+ 
+   len = strlen( name );
+ 
+   ep = environ;
+   while (*ep != NULL)
+     if (! strncmp( *ep, name, len ) && (*ep)[len] == '=')
+     {
+ /* Found it.  Remove this pointer by moving later ones back.  */
+       char **dp = ep;
+ 
+       do
+         dp[0] = dp[1];
+       while (*dp++);
+ /* Continue the loop in case NAME appears again.  */
+     }
+   else
+     ++ep;
+ 
+   return( 0 );
+ }
+ #endif
+ 
+ 
  /*
   *  Inits pty and tty and forks a login process.
   *  Does not close fd Xsocket.
*** ./xterm.h.ORIG	Fri Aug 28 16:36:37 2020
--- ./xterm.h	Fri Aug 28 16:37:26 2020
***************
*** 1198,1203 ****
--- 1198,1206 ----
  extern void timestamp_filename(char * /* dst */, const char * /* src */);
  extern void update_winsize(int /* fd */, int /* rows */, int /* cols */, int /* height */, int /* width */);
  extern void xevents (XtermWidget /* xw */);
+ #ifndef _X_NORETURN
+ #define _X_NORETURN
+ #endif
  extern void xt_error (String /* message */) GCC_NORETURN;
  extern void xtermBell(XtermWidget /* xw */, int /* which */, int /* percent */);
  extern void xtermCopyEnv (char ** /* oldenv */);