From 401fbd077b458eda711e41c4cc37ef977f94b0cf Mon Sep 17 00:00:00 2001
From: Klaus2m5 <K@2m5.de>
Date: Thu, 10 Dec 2015 14:24:11 +0100
Subject: [PATCH] added error 247 - input buffer overlap

linbuf & progbuf might overlap when automatic statement expansion (N+1
-> N=N+1) is used excessively.
---
 vtl02sg.a65 | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/vtl02sg.a65 b/vtl02sg.a65
index 9016fed..6a1900a 100644
--- a/vtl02sg.a65
+++ b/vtl02sg.a65
@@ -249,6 +249,7 @@
 ;       244 value or variable missing after operator
 ;       245 missing closing parenthesis
 ;       246 out of memory (*-&)
+;       247 overlap in input buffer, split program line
 ;
 ; internal changes:
 ;   added required atomic variable fetch & store.
@@ -1732,7 +1733,14 @@ syndbl:
     sta  prgbuf,x
     inx
     ldy  arg+4      ; repeat variable & operator
-    jmp  syndbl1
+    tya
+    clc             ; test buffer will not overlap
+    adc  #$20
+    sta  arg+4
+    cpx  arg+4
+    bcc  syndbl1
+    lda  #$f7       ; buffers overlap error
+    jmp  verr
 
 synerr3:
     lda  #$f2       ; invalid or missing operator