From c36495dce759adbd3c65d047a778f76db4c34c43 Mon Sep 17 00:00:00 2001
From: Mike Drob <mdrob@apache.org>
Date: Fri, 20 Aug 2021 15:40:52 -0500
Subject: [PATCH] LUCENE-10017 Less verbose exception on IndexFormatTooOld
 (#200)

---
 .../org/apache/lucene/codecs/CodecUtil.java     | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lucene/core/src/java/org/apache/lucene/codecs/CodecUtil.java b/lucene/core/src/java/org/apache/lucene/codecs/CodecUtil.java
index a0a3f906260..921ffdb16b1 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/CodecUtil.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/CodecUtil.java
@@ -490,12 +490,17 @@ public final class CodecUtil {
 
           // now check the footer
           long checksum = checkFooter(in);
-          priorException.addSuppressed(
-              new CorruptIndexException(
-                  "checksum passed ("
-                      + Long.toHexString(checksum)
-                      + "). possibly transient resource issue, or a Lucene or JVM bug",
-                  in));
+          if (!(priorException instanceof IndexFormatTooOldException)) {
+            // If the index format is too old and no corruption, do not add checksums
+            // matching message since this may tend to unnecessarily alarm people who
+            // see "JVM bug" in their logs
+            priorException.addSuppressed(
+                new CorruptIndexException(
+                    "checksum passed ("
+                        + Long.toHexString(checksum)
+                        + "). possibly transient resource issue, or a Lucene or JVM bug",
+                    in));
+          }
         }
       } catch (CorruptIndexException corruptException) {
         corruptException.addSuppressed(priorException);