Only update hash when there is more data

1 files changed, 3 insertions, 1 deletions

diff --git a/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/LazyFileReferenceData.java b/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/LazyFileReferenceData.java
index 5e7fd08e52f..1681843a818 100644
--- a/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/LazyFileReferenceData.java
+++ b/filedistribution/src/main/java/com/yahoo/vespa/filedistribution/LazyFileReferenceData.java
@@ -30,7 +30,9 @@ public class LazyFileReferenceData extends FileReferenceData {
         } catch (IOException e) {
             return -1;
         }
-        hasher.update(bb.array(), pos, read);
+        if (read > 0) {
+            hasher.update(bb.array(), pos, read);
+        }
         return read;
     }