From 11079efed441ab7394badf0c3c8ea972315e3512 Mon Sep 17 00:00:00 2001
From: Michael McCandless <mikemccand@apache.org>
Date: Fri, 6 Mar 2009 11:22:12 +0000
Subject: [PATCH] LUCENE-1554: remove false-positive assert that may (rarely)
 trip when it's not supposed to

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@750849 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/lucene/index/IndexWriter.java   | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/java/org/apache/lucene/index/IndexWriter.java b/src/java/org/apache/lucene/index/IndexWriter.java
index 3a39f59bc09..bfb6bb9698f 100644
--- a/src/java/org/apache/lucene/index/IndexWriter.java
+++ b/src/java/org/apache/lucene/index/IndexWriter.java
@@ -4427,14 +4427,16 @@ public class IndexWriter {
     if (merge.increfDone)
       decrefMergeSegments(merge);
 
-    assert merge.registerDone;
-
-    final SegmentInfos sourceSegments = merge.segments;
-    final int end = sourceSegments.size();
-    for(int i=0;i<end;i++)
-      mergingSegments.remove(sourceSegments.info(i));
-    mergingSegments.remove(merge.info);
-    merge.registerDone = false;
+    // It's possible we are called twice, eg if there was an
+    // exception inside mergeInit
+    if (merge.registerDone) {
+      final SegmentInfos sourceSegments = merge.segments;
+      final int end = sourceSegments.size();
+      for(int i=0;i<end;i++)
+        mergingSegments.remove(sourceSegments.info(i));
+      mergingSegments.remove(merge.info);
+      merge.registerDone = false;
+    }
   }
 
   /** Does the actual (time-consuming) work of the merge,