--- tcsh-6.14.00/sh.lex.c.wide-crash	2006-02-28 03:34:58.000000000 +0100
+++ tcsh-6.14.00/sh.lex.c	2006-02-28 03:35:31.000000000 +0100
@@ -1710,13 +1710,13 @@
 	    break;
 	partial += r;
 	i = 0;
-	while (i < partial) {
+	while (i < partial && nchars != 0) {
 	    int len;
 
 	    len = normal_mbtowc(buf + res, cbuf + i, partial - i);
 	    if (len == -1) {
 	        reset_mbtowc();
-		if (partial < MB_LEN_MAX && r > 0)
+		if (partial - i < MB_LEN_MAX && r > 0)
 		    /* Maybe a partial character and there is still a chance
 		       to read more */
 		    break;
@@ -1735,7 +1735,7 @@
 	if (i != partial)
 	    memmove(cbuf, cbuf + i, partial - i);
 	partial -= i;
-    } while (partial != 0);
+    } while (partial != 0 && nchars != 0);
     /* Throwing away possible partial multibyte characters on error */
     return res != 0 ? res : r;
 }