add additional diagnostic info on failures

git-svn-id: https://svn.code.sf.net/p/jackcess/code/jackcess/trunk@260 f203690c-595d-4dc9-a70b-905162fa7fd2

diff --git a/src/java/com/healthmarketscience/jackcess/UsageMap.java b/src/java/com/healthmarketscience/jackcess/UsageMap.java
index a6b81ade8bdf50b2a74f05bc88589e4cde98778c..551c8a5b3fd29bbb153360dab458aa6f76f4d582 100644 (file)
--- a/src/java/com/healthmarketscience/jackcess/UsageMap.java
+++ b/src/java/com/healthmarketscience/jackcess/UsageMap.java
@@ -325,7 +325,8 @@ public class UsageMap
     if(isOn == add) {
       throw new IOException("Page number " + absolutePageNumber + " already " +
                             ((add) ? "added to" : "removed from") +
-                            " usage map");
+                            " usage map, expected range " +
+                            _startPage + " to " + _endPage);
     }
     
     //Apply the bitmask