From 5280263232c962a61905ccaed76fedf89486268b Mon Sep 17 00:00:00 2001
From: Matthias Wahl <matthias@crate.io>
Date: Tue, 10 Mar 2015 14:22:22 +0100
Subject: [PATCH] fix ordering with a scalar on a column containing NULL

---
 CHANGES.txt                                      |  3 +++
 .../action/sql/query/CrateSearchService.java     |  4 ++--
 .../ArithmeticIntegrationTest.java               | 16 ++++++++++++++++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 7e30fa6fc291..a7191151f7b8 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,6 +5,9 @@ Changes for Crate
 Unreleased
 ==========
 
+ - Fix: Sorting on a scalar with a column containing NULL values as
+   argument no longer throws an NPE
+
  - Fix: group by on clustered by column on a partitioned table now produces
    correct results for groups spanning different partitions
 
diff --git a/sql/src/main/java/io/crate/action/sql/query/CrateSearchService.java b/sql/src/main/java/io/crate/action/sql/query/CrateSearchService.java
index c8162352ee08..9c05cb656c12 100644
--- a/sql/src/main/java/io/crate/action/sql/query/CrateSearchService.java
+++ b/sql/src/main/java/io/crate/action/sql/query/CrateSearchService.java
@@ -499,7 +499,7 @@ public int compareBottom(int doc) throws IOException {
                 LuceneCollectorExpression collectorExpression = collectorExpressions.get(i);
                 collectorExpression.setNextDocId(doc);
             }
-            return valueType.compareValueTo(bottom, input.value());
+            return valueType.compareValueTo(bottom, MoreObjects.firstNonNull(input.value(), missingValue));
         }
 
         @SuppressWarnings("unchecked")
@@ -509,7 +509,7 @@ public int compareTop(int doc) throws IOException {
                 LuceneCollectorExpression collectorExpression = collectorExpressions.get(i);
                 collectorExpression.setNextDocId(doc);
             }
-            return valueType.compareValueTo(top, input.value());
+            return valueType.compareValueTo(top, MoreObjects.firstNonNull(input.value(), missingValue));
         }
 
         @Override
diff --git a/sql/src/test/java/io/crate/integrationtests/ArithmeticIntegrationTest.java b/sql/src/test/java/io/crate/integrationtests/ArithmeticIntegrationTest.java
index e6e9530193cb..710e2b3e190e 100644
--- a/sql/src/test/java/io/crate/integrationtests/ArithmeticIntegrationTest.java
+++ b/sql/src/test/java/io/crate/integrationtests/ArithmeticIntegrationTest.java
@@ -383,4 +383,20 @@ public void testArithmeticScalarFunctionsOnAllTypes() throws Exception {
             execute(String.format(Locale.ENGLISH, "select %s, d from t where %s < 2", doubleCall, doubleCall));
         }
     }
+
+    @Test
+    public void testSelectOrderByScalarOnNullValue() throws Exception {
+        execute("create table t (d long, name string) clustered into 1 shards with (number_of_replicas=0)");
+        ensureGreen();
+        execute("insert into t (d, name) values (?, ?)", new Object[][] {
+                new Object[] {-7L, "Marvin" },
+                new Object[] {null, "Arthur" },
+                new Object[] {5L, "Trillian" },
+                new Object[] {null, "Trillian" }
+
+        } );
+        execute("refresh table t");
+        execute("select (d - 10) from t order by (d - 10) nulls first limit 2");
+        assertThat(response.rows()[0][0], is(nullValue()));
+    }
 }