[github-191] Fix RuntimeException on array formula referencing blank cell. Thanks to Miłosz Rembisz. This closes #191

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1880844 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 6 insertions, 0 deletions

diff --git a/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java b/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
index 060f274ef0..77d0937876 100644
--- a/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
+++ b/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
@@ -633,6 +633,12 @@ public final class WorkbookEvaluator {
         else {
             value = dereferenceResult(evaluationResult, ec.getRowIndex(), ec.getColumnIndex());
         }
+        if (value == BlankEval.instance) {
+            // Note Excel behaviour here. A blank final final value is converted to zero.
+            return NumberEval.ZERO;
+            // Formulas _never_ evaluate to blank.  If a formula appears to have evaluated to
+            // blank, the actual value is empty string. This can be verified with ISBLANK().
+        }
         
         return value;
     }