From b6c6e4f9e4543000a2a290c97e87d44177ec7df0 Mon Sep 17 00:00:00 2001
From: Anton Persson <anton.persson@neotechnology.com>
Date: Tue, 14 Nov 2017 10:28:55 +0100
Subject: [PATCH] FusionIndexReader validate index order on queries

---
 .../schema/NativeSchemaNumberIndexReader.java   |  8 ++------
 .../index/schema/fusion/FusionIndexReader.java  |  9 +++++++++
 .../fusion/FusionSchemaIndexProvider.java       | 17 ++++++++++++++++-
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/NativeSchemaNumberIndexReader.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/NativeSchemaNumberIndexReader.java
index cab2d25b37f6b..0383732fad236 100644
--- a/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/NativeSchemaNumberIndexReader.java
+++ b/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/NativeSchemaNumberIndexReader.java
@@ -161,12 +161,8 @@ private void validateQuery( IndexOrder indexOrder, IndexQuery[] predicates )
 
         if ( indexOrder != null )
         {
-            ValueGroup[] valueGroups = new ValueGroup[predicates.length];
-            for ( int i = 0; i < predicates.length; i++ )
-            {
-                valueGroups[i] = predicates[i].valueGroup();
-            }
-            IndexOrder[] capability = NativeSchemaNumberIndexProvider.CAPABILITY.orderCapability( valueGroups );
+            ValueGroup valueGroup = predicates[0].valueGroup();;
+            IndexOrder[] capability = NativeSchemaNumberIndexProvider.CAPABILITY.orderCapability( valueGroup );
             if ( !ArrayUtil.contains( capability, indexOrder ) )
             {
                 throw new UnsupportedOperationException(
diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionIndexReader.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionIndexReader.java
index f8da35f72030f..3dc1bb0e903be 100644
--- a/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionIndexReader.java
+++ b/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionIndexReader.java
@@ -20,6 +20,7 @@
 package org.neo4j.kernel.impl.index.schema.fusion;
 
 import java.util.ArrayDeque;
+import java.util.Arrays;
 import java.util.Queue;
 
 import org.neo4j.collection.primitive.PrimitiveLongCollections;
@@ -36,6 +37,8 @@
 import org.neo4j.storageengine.api.schema.IndexSampler;
 import org.neo4j.values.storable.Value;
 
+import static java.lang.String.format;
+
 class FusionIndexReader implements IndexReader
 {
     private final IndexReader nativeReader;
@@ -132,6 +135,12 @@ public void query( IndexProgressor.NodeValueClient cursor, IndexOrder indexOrder
         // todo: There will be no ordering of the node ids here. Is this a problem?
         if ( predicates[0] instanceof ExistsPredicate )
         {
+            if ( indexOrder != IndexOrder.UNORDERED )
+            {
+                throw new UnsupportedOperationException(
+                        format( "Tried to query index with unsupported order %s. Supported orders for query %s are %s.",
+                                indexOrder, Arrays.toString( predicates ), Arrays.toString( new IndexOrder[]{IndexOrder.UNORDERED} ) ) );
+            }
             BridgingIndexProgressor multiProgressor = new BridgingIndexProgressor( cursor, propertyKeys );
             cursor.initialize( multiProgressor, propertyKeys );
             nativeReader.query( multiProgressor, indexOrder, predicates[0] );
diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionSchemaIndexProvider.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionSchemaIndexProvider.java
index 93f4c1b038137..52f1d67f931ef 100644
--- a/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionSchemaIndexProvider.java
+++ b/community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/fusion/FusionSchemaIndexProvider.java
@@ -22,6 +22,7 @@
 import java.io.IOException;
 
 import org.neo4j.internal.kernel.api.IndexCapability;
+import org.neo4j.internal.kernel.api.IndexOrder;
 import org.neo4j.io.fs.FileSystemAbstraction;
 import org.neo4j.io.pagecache.PageCache;
 import org.neo4j.kernel.api.index.IndexAccessor;
@@ -35,6 +36,7 @@
 import org.neo4j.kernel.impl.storemigration.StoreMigrationParticipant;
 import org.neo4j.storageengine.api.schema.IndexSample;
 import org.neo4j.values.storable.Value;
+import org.neo4j.values.storable.ValueGroup;
 
 /**
  * This {@link SchemaIndexProvider index provider} act as one logical index but is backed by two physical
@@ -132,7 +134,20 @@ public IndexCapability getCapability( IndexDescriptor indexDescriptor )
     {
         IndexCapability nativeCapability = nativeProvider.getCapability( indexDescriptor );
         IndexCapability luceneCapability = luceneProvider.getCapability( indexDescriptor );
-        return new UnionIndexCapability( nativeCapability, luceneCapability );
+        return new UnionIndexCapability( nativeCapability, luceneCapability )
+        {
+            @Override
+            public IndexOrder[] orderCapability( ValueGroup... valueGroups )
+            {
+                // No order capability when combining results from different indexes
+                if ( valueGroups.length == 1 && valueGroups[0] == null )
+                {
+                    return new IndexOrder[]{IndexOrder.UNORDERED};
+                }
+                // Otherwise union of capabilities
+                return super.orderCapability( valueGroups );
+            }
+        };
     }
 
     @Override