JoinSql visitor will visit left side if left is a join

2 files changed, 44 insertions, 3 deletions

diff --git a/lib/arel/visitors/join_sql.rb b/lib/arel/visitors/join_sql.rb
index ab3d10f99c..099e78b692 100644
--- a/lib/arel/visitors/join_sql.rb
+++ b/lib/arel/visitors/join_sql.rb
@@ -17,15 +17,21 @@ module Arel
         [
           (visit o.left if Nodes::Join === o.left),
           visit(o.right)
-        ].join ' '
+        ].compact.join ' '
       end
 
       def visit_Arel_Nodes_OuterJoin o
-        "LEFT OUTER JOIN #{visit o.right} #{visit o.constraint}"
+        [
+          (visit o.left if Nodes::Join === o.left),
+          "LEFT OUTER JOIN #{visit o.right} #{visit o.constraint if o.constraint}"
+        ].compact.join ' '
       end
 
       def visit_Arel_Nodes_InnerJoin o
-        "INNER JOIN #{visit o.right} #{visit o.constraint if o.constraint}"
+        [
+          (visit o.left if Nodes::Join === o.left),
+          "INNER JOIN #{visit o.right} #{visit o.constraint if o.constraint}"
+        ].compact.join ' '
       end
     end
   end
diff --git a/spec/arel/visitors/join_sql_spec.rb b/spec/arel/visitors/join_sql_spec.rb
new file mode 100644
index 0000000000..9064dae852
--- /dev/null
+++ b/spec/arel/visitors/join_sql_spec.rb
@@ -0,0 +1,35 @@
+require 'spec_helper'
+
+module Arel
+  module Visitors
+    describe 'the join_sql visitor' do
+      before do
+        @visitor = JoinSql.new Table.engine
+      end
+
+      describe 'inner join' do
+        it 'should visit left if left is a join' do
+          t    = Table.new :users
+          join = Nodes::InnerJoin.new t, t, Nodes::On.new(t[:id])
+          j2   = Nodes::InnerJoin.new join, t, Nodes::On.new(t[:id])
+          @visitor.accept(j2).should be_like %{
+            INNER JOIN "users" ON "users"."id"
+            INNER JOIN "users" ON "users"."id"
+          }
+        end
+      end
+
+      describe 'outer join' do
+        it 'should visit left if left is a join' do
+          t    = Table.new :users
+          join = Nodes::OuterJoin.new t, t, Nodes::On.new(t[:id])
+          j2   = Nodes::OuterJoin.new join, t, Nodes::On.new(t[:id])
+          @visitor.accept(j2).should be_like %{
+            LEFT OUTER JOIN "users" ON "users"."id"
+            LEFT OUTER JOIN "users" ON "users"."id"
+          }
+        end
+      end
+    end
+  end
+end