Do not generate NOT IN (NULL) when empty right

2 files changed, 5 insertions, 5 deletions

diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index a6be451e6f..cb8df8329a 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -467,7 +467,7 @@ key on UpdateManager using UpdateManager#key=
       alias :visit_Arel_Nodes_Division       :visit_Arel_Nodes_InfixOperation
 
       def visit_Array o
-        o.empty? ? 'NULL' : o.map { |x| visit x }.join(', ')
+        o.map { |x| visit x }.join(', ')
       end
 
       def quote value, column = nil
diff --git a/test/visitors/test_to_sql.rb b/test/visitors/test_to_sql.rb
index f832bdf925..58eec1f63b 100644
--- a/test/visitors/test_to_sql.rb
+++ b/test/visitors/test_to_sql.rb
@@ -167,10 +167,10 @@ module Arel
           }
         end
 
-        it "should turn empty right to NULL" do
+        it "should return IN () when empty right which is invalid SQL" do
           node = @attr.in []
           @visitor.accept(node).must_be_like %{
-            "users"."id" IN (NULL)
+            "users"."id" IN ()
           }
         end
 
@@ -255,10 +255,10 @@ module Arel
           }
         end
 
-        it "should turn empty right to NULL" do
+        it "should return NOT IN () when empty right which is invalid SQL" do
           node = @attr.not_in []
           @visitor.accept(node).must_be_like %{
-            "users"."id" NOT IN (NULL)
+            "users"."id" NOT IN ()
           }
         end