From 2097a2765f1d6d9786f7f5346f3ea2bbee104fae Mon Sep 17 00:00:00 2001
From: Denis Molony <dmolony@iinet.net.au>
Date: Sat, 19 Mar 2016 16:54:58 +1100
Subject: [PATCH] substitute @NA for non-existent cell

---
 src/com/bytezone/diskbrowser/visicalc/Condition.java  | 2 +-
 src/com/bytezone/diskbrowser/visicalc/Expression.java | 2 ++
 src/com/bytezone/diskbrowser/visicalc/If.java         | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/com/bytezone/diskbrowser/visicalc/Condition.java b/src/com/bytezone/diskbrowser/visicalc/Condition.java
index 18917a1..8e18347 100644
--- a/src/com/bytezone/diskbrowser/visicalc/Condition.java
+++ b/src/com/bytezone/diskbrowser/visicalc/Condition.java
@@ -48,7 +48,7 @@ class Condition
     //    System.out.println (conditionText);
     if (conditionExpression == null)
     {
-      //      System.out.printf ("creating %s%n", conditionText);
+      System.out.printf ("creating %s %s %s%n", conditionText, comparator, valueText);
       conditionExpression = new Expression (parent, conditionText);
       //      System.out.printf ("creating %s%n", valueText);
       valueExpression = new Expression (parent, valueText);
diff --git a/src/com/bytezone/diskbrowser/visicalc/Expression.java b/src/com/bytezone/diskbrowser/visicalc/Expression.java
index 5371b1f..fac80d7 100644
--- a/src/com/bytezone/diskbrowser/visicalc/Expression.java
+++ b/src/com/bytezone/diskbrowser/visicalc/Expression.java
@@ -94,6 +94,8 @@ class Expression implements Value
             Cell cell = parent.getCell (addressText);
             if (cell != null)
               values.add (parent.getCell (addressText));
+            else
+              values.add (Function.getInstance (parent, "@NA"));
           }
           else
           {
diff --git a/src/com/bytezone/diskbrowser/visicalc/If.java b/src/com/bytezone/diskbrowser/visicalc/If.java
index 7b80996..21995ba 100644
--- a/src/com/bytezone/diskbrowser/visicalc/If.java
+++ b/src/com/bytezone/diskbrowser/visicalc/If.java
@@ -27,6 +27,7 @@ class If extends Function
   {
     valueType = ValueType.VALUE;
 
+    System.out.println (functionText);
     if (condition.getResult ())
     {
       //      System.out.println ("true");