merging changes back from master
diff --git a/solr/core/src/java/org/apache/solr/core/ConfigSet.java b/solr/core/src/java/org/apache/solr/core/ConfigSet.java
index 7161bc1..7e17559 100644
--- a/solr/core/src/java/org/apache/solr/core/ConfigSet.java
+++ b/solr/core/src/java/org/apache/solr/core/ConfigSet.java
@@ -30,7 +30,7 @@
   private final String name;
 
   private final SolrConfig solrconfig;
-  private IndexSchema schema;
+  private volatile IndexSchema schema;
 
   private final SchemaSupplier schemaSupplier;