diff -upr tcsh-6.18.00_orig/ed.chared.c tcsh-6.18.00_work/ed.chared.c
--- tcsh-6.18.00_orig/ed.chared.c	2013-03-28 10:26:00.801939093 +0100
+++ tcsh-6.18.00_work/ed.chared.c	2013-03-28 10:30:37.000000000 +0100
@@ -957,6 +957,7 @@ GetHistLine()
 {
     struct Hist *hp;
     int     h;
+    int     history;
 
     if (Hist_num == 0) {	/* if really the current line */
 	if (HistBuf.s != NULL)
@@ -979,8 +980,10 @@ GetHistLine()
     if (hp == NULL)
 	return(CC_ERROR);
 
+    /* access only $history commands */
+    history = getn(varval(STRhistory));
     for (h = 1; h < Hist_num; h++) {
-	if ((hp->Hnext) == NULL) {
+	if ((hp->Hnext) == NULL || h >= history) {
 	    Hist_num = h;
 	    return(CC_ERROR);
 	}
diff -upr tcsh-6.18.00_orig/sh.hist.c tcsh-6.18.00_work/sh.hist.c
--- tcsh-6.18.00_orig/sh.hist.c	2013-03-28 10:26:00.794939068 +0100
+++ tcsh-6.18.00_work/sh.hist.c	2013-03-28 10:25:19.000000000 +0100
@@ -138,6 +138,7 @@ savehist(
   int flg)
 {
     int histlen = 0;
+    int savehist = 0;
     Char   *cp;
 
     /* throw away null lines */
@@ -151,6 +152,20 @@ savehist(
 	}
 	histlen = histlen * 10 + *cp++ - '0';
     }
+
+    /* check savehist and history and use greater value to store all commands */
+    cp = varval(STRsavehist);
+    while (*cp) {
+	if (!Isdigit(*cp)) {
+	    savehist = 0;
+	    break;
+	}
+	savehist = savehist * 10 + *cp++ - '0';
+    }
+
+    if (savehist > histlen)
+	histlen = savehist;
+
     if (sp)
         (void) enthist(++eventno, sp, 1, flg, histlen);
     discardExcess(histlen, flg);