Merge pull request #277 from sergey-alekseev/wrap-nested-gropings-only-once

Wrap nested Nodes::Grouping in brackets only once

2 files changed, 13 insertions, 2 deletions

diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 8c63070084..ae1b7930af 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -436,8 +436,12 @@ module Arel
       end
 
       def visit_Arel_Nodes_Grouping o, collector
-        collector << "("
-        visit(o.expr, collector) << ")"
+        if o.expr.is_a? Nodes::Grouping
+          visit(o.expr, collector)
+        else
+          collector << "("
+          visit(o.expr, collector) << ")"
+        end
       end
 
       def visit_Arel_SelectManager o, collector
diff --git a/test/visitors/test_to_sql.rb b/test/visitors/test_to_sql.rb
index a88c888908..c03d89cfef 100644
--- a/test/visitors/test_to_sql.rb
+++ b/test/visitors/test_to_sql.rb
@@ -131,6 +131,13 @@ module Arel
         end
       end
 
+      describe 'Nodes::Grouping' do
+        it 'wraps nested groupings in brackets only once' do
+          sql = compile Nodes::Grouping.new(Nodes::Grouping.new(Nodes.build_quoted('foo')))
+          sql.must_equal "('foo')"
+        end
+      end
+
       describe 'Nodes::NotEqual' do
         it 'should handle false' do
           val = Nodes.build_quoted(false, @table[:active])