Fixed that postgresql adapter would fails when reading bytea fields with null...

Fixed that postgresql adapter would fails when reading bytea fields with null value #771 [rodrigo k]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@849 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -143,11 +143,11 @@ def quote_bytea(s)
         end
 
         def escape_bytea(s)
-          s.gsub(/\\/) { '\\\\\\\\' }.gsub(/[^\\]/) { |c| sprintf('\\\\%03o', c[0].to_i) }
+          s.gsub(/\\/) { '\\\\\\\\' }.gsub(/[^\\]/) { |c| sprintf('\\\\%03o', c[0].to_i) } unless s.nil?
         end
 
         def unescape_bytea(s)
-          s.gsub(/\\([0-9][0-9][0-9])/) { $1.oct.chr }.gsub(/\\\\/) { '\\' }
+          s.gsub(/\\([0-9][0-9][0-9])/) { $1.oct.chr }.gsub(/\\\\/) { '\\' } unless s.nil?
         end
 
         def split_table_schema(table_name)