diff -ur pdksh-5.2.14.orig/history.c pdksh-5.2.14/history.c
--- pdksh-5.2.14.orig/history.c	Mon May 10 15:13:06 1999
+++ pdksh-5.2.14/history.c	Mon Aug  7 00:06:33 2000
@@ -610,7 +610,18 @@
 {
 	register char **hp = histptr;
 	char *cp;
+	int l;
 
+	/* don't save if command is the same as last one */
+	if (hp >= history && *hp != NULL) {
+		l = strlen(cmd);
+		if (strcmp(*hp, cmd) == 0)
+			return;
+		else if ((cmd[l-1] == '\n')
+				&& (strlen(*hp) == l-1)
+				&& strncmp(*hp, cmd, l - 1) == 0)
+			return;
+	}
 	if (++hp >= history + histsize) { /* remove oldest command */
 		afree((void*)history[0], APERM);
 		memmove(history, history + 1,
@@ -700,9 +711,13 @@
 				nread = fread(hline, 1, LINE, fh);
 				if (nread <= 0)
 					break;
-				hline[nread] = '\0';
+				hline[nread] = '\n';
 			}
-			end = strchr(hline + pos, 0); /* will always succeed */
+			end = strchr(hline + pos, '\n'); /* will always succeed - 0, but not \n!!! */
+			if(end != NULL) /* in case sth put \0 in .history...) */
+				*end = '\0';
+			else
+				end = strchr(hline + pos, '\0'); /* THIS will always succeed */
 			if (contin)
 				histappend(hline + pos, 0);
 			else {
@@ -742,7 +754,7 @@
   if (hname && (fh = fopen(hname, "w")))
   {
     for (i = 0; hp + i <= histptr && hp[i]; i++)
-      fprintf(fh, "%s%c", hp[i], '\0');
+      fprintf(fh, "%s\n", hp[i]);
     fclose(fh);
   }
 }