From 14de8051d89ce11ee0e9105fd1d4584b7585a54e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Louise=20S=C3=B6derstr=C3=B6m?= <louise.matematik@gmail.com>
Date: Tue, 16 Jan 2018 17:33:18 +0100
Subject: [PATCH] Solve nested unwind bug in compiled runtime and add some
 feature tests.

---
 .../codegen/CompiledConversionUtils.java      | 63 ++++++++++++-------
 .../resources/blacklists/compatibility-23.txt |  5 ++
 .../cypher/features/UnwindAcceptance.feature  | 54 ++++++++++++++++
 3 files changed, 101 insertions(+), 21 deletions(-)

diff --git a/community/cypher/cypher/src/main/java/org/neo4j/cypher/internal/codegen/CompiledConversionUtils.java b/community/cypher/cypher/src/main/java/org/neo4j/cypher/internal/codegen/CompiledConversionUtils.java
index 7149ab843cb0..b887bb6ca9ef 100644
--- a/community/cypher/cypher/src/main/java/org/neo4j/cypher/internal/codegen/CompiledConversionUtils.java
+++ b/community/cypher/cypher/src/main/java/org/neo4j/cypher/internal/codegen/CompiledConversionUtils.java
@@ -400,14 +400,26 @@ else if ( iterable instanceof PrimitiveEntityStream )
         {
             return ((PrimitiveEntityStream) iterable).iterator();
         }
+        else if ( iterable instanceof Long)
+        {
+            return (LongStream.of((Long) iterable)).iterator();
+        }
         else if ( iterable instanceof LongStream )
         {
             return ((LongStream) iterable).iterator();
         }
+        else if ( iterable instanceof Double)
+        {
+            return (DoubleStream.of((Double) iterable)).iterator();
+        }
         else if ( iterable instanceof DoubleStream )
         {
             return ((DoubleStream) iterable).iterator();
         }
+        else if ( iterable instanceof Integer)
+        {
+            return (IntStream.of((Integer) iterable)).iterator();
+        }
         else if ( iterable instanceof IntStream )
         {
             return ((IntStream) iterable).iterator();
@@ -416,30 +428,15 @@ else if ( iterable == null )
         {
             return Collections.emptyIterator();
         }
+        else if ( iterable instanceof String )
+        {
+            String[] singleStringArray = {(String) iterable};
+            return getIterator( singleStringArray, 1 );
+        }
         else if ( iterable.getClass().isArray() )
         {
             int len = Array.getLength( iterable );
-
-            return new Iterator()
-            {
-                private int position = 0;
-
-                @Override
-                public boolean hasNext()
-                {
-                    return position < len;
-                }
-
-                @Override
-                public Object next()
-                {
-                    if ( position >= len )
-                    {
-                        throw new NoSuchElementException();
-                    }
-                    return Array.get( iterable, position++ );
-                }
-            };
+            return getIterator( iterable, len );
         }
         else
         {
@@ -448,6 +445,30 @@ public Object next()
         }
     }
 
+    private static Iterator getIterator( Object iterable, int len )
+    {
+        return new Iterator()
+        {
+            private int position = 0;
+
+            @Override
+            public boolean hasNext()
+            {
+                return position < len;
+            }
+
+            @Override
+            public Object next()
+            {
+                if ( position >= len )
+                {
+                    throw new NoSuchElementException();
+                }
+                return Array.get( iterable, position++ );
+            }
+        };
+    }
+
     @SuppressWarnings( "unchecked" )
     public static LongStream toLongStream( Object list )
     {
diff --git a/enterprise/cypher/acceptance-spec-suite/src/test/resources/blacklists/compatibility-23.txt b/enterprise/cypher/acceptance-spec-suite/src/test/resources/blacklists/compatibility-23.txt
index fa977abe7cba..cfe06213e636 100644
--- a/enterprise/cypher/acceptance-spec-suite/src/test/resources/blacklists/compatibility-23.txt
+++ b/enterprise/cypher/acceptance-spec-suite/src/test/resources/blacklists/compatibility-23.txt
@@ -65,3 +65,8 @@ Negative parameter for LIMIT should not generate errors
 
 //IndexAcceptance.feature
 STARTS WITH should handle null prefix
+
+//UnwindAcceptance.feature
+Nested unwind with longs
+Nested unwind with doubles
+Nested unwind with strings
diff --git a/enterprise/cypher/acceptance-spec-suite/src/test/resources/cypher/features/UnwindAcceptance.feature b/enterprise/cypher/acceptance-spec-suite/src/test/resources/cypher/features/UnwindAcceptance.feature
index 6e2dcc247a63..d26272c4200d 100644
--- a/enterprise/cypher/acceptance-spec-suite/src/test/resources/cypher/features/UnwindAcceptance.feature
+++ b/enterprise/cypher/acceptance-spec-suite/src/test/resources/cypher/features/UnwindAcceptance.feature
@@ -228,3 +228,57 @@ Feature: UnwindAcceptance
       | 'c'   |
     And no side effects
 
+  Scenario: Nested unwind with longs
+    Given an empty graph
+    When executing query:
+      """
+      WITH [[1, 2], [3, 4], 5] AS nested
+          UNWIND nested AS x
+          UNWIND x AS y
+          RETURN y
+      """
+    Then the result should be:
+        | y |
+        | 1 |
+        | 2 |
+        | 3 |
+        | 4 |
+        | 5 |
+    And no side effects
+
+  Scenario: Nested unwind with doubles
+    Given an empty graph
+    When executing query:
+      """
+      WITH [[1.5, 2.5], [3.5, 4.5], 5.5] AS nested
+          UNWIND nested AS x
+          UNWIND x AS y
+          RETURN y
+      """
+    Then the result should be:
+      | y   |
+      | 1.5 |
+      | 2.5 |
+      | 3.5 |
+      | 4.5 |
+      | 5.5 |
+    And no side effects
+
+  Scenario: Nested unwind with strings
+    Given an empty graph
+    When executing query:
+      """
+      WITH [['a', 'b'], ['c', 'd'], 'e'] AS nested
+          UNWIND nested AS x
+          UNWIND x AS y
+          RETURN y
+      """
+    Then the result should be:
+      | y   |
+      | 'a' |
+      | 'b' |
+      | 'c' |
+      | 'd' |
+      | 'e' |
+    And no side effects
+