From 4a4e6ddbb9b25d07fe44f3dbee57882808f2e87f Mon Sep 17 00:00:00 2001
From: Paul Gardner-Stephen <paul@servalproject.org>
Date: Sun, 28 Apr 2019 20:48:46 +0930
Subject: [PATCH] fix Issue #13

---
 c64/basic/basic_shift_mem_down.s | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/c64/basic/basic_shift_mem_down.s b/c64/basic/basic_shift_mem_down.s
index b23af5ce..e866828b 100644
--- a/c64/basic/basic_shift_mem_down.s
+++ b/c64/basic/basic_shift_mem_down.s
@@ -98,11 +98,21 @@ basic_shift_mem_down_and_relink:
 	;; Get length of deletion back
 	pla
 	sta tokenise_work3
+
+	;; Check if we still have any lines left
+	ldy #0
+	ldx #<basic_current_line_ptr
+	jsr peek_pointer_null_check
+	bcs relink_down_next_line
+	;; Nope, so just return
+	clc
+	rts
+
 	
 relink_down_next_line:
 	;; inc $d020
 	;; jmp relink_down_next_line
-
+	
 	;; Subtract tokenise_work3 from the pointer
 	ldy #0
 	ldx #<basic_current_line_ptr+0