Get rid of warnings generated by calling obsolete .to_a method on a Symbol

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2341 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb

@@ -54,12 +54,12 @@ def rename_column(table_name, column_name, new_column_name)
       end
 
       # Create a new index on the given table. By default, it will be named
-      # <code>"#{table_name}_#{column_name.to_a.first}_index"</code>, but you
+      # <code>"#{table_name}_#{Array(column_name).first}_index"</code>, but you
       # can explicitly name the index by passing <code>:name => "..."</code>
       # as the last parameter. Unique indexes may be created by passing
       # <code>:unique => true</code>.
       def add_index(table_name, column_name, options = {})
-        index_name = "#{table_name}_#{column_name.to_a.first}_index"
+        index_name = "#{table_name}_#{Array(column_name).first}_index"
 
         if Hash === options # legacy support, since this param was a string
           index_type = options[:unique] ? "UNIQUE" : ""
@@ -68,7 +68,7 @@ def add_index(table_name, column_name, options = {})
           index_type = options
         end
 
-        execute "CREATE #{index_type} INDEX #{index_name} ON #{table_name} (#{column_name.to_a.join(", ")})"
+        execute "CREATE #{index_type} INDEX #{index_name} ON #{table_name} (#{Array(column_name).join(", ")})"
       end
 
       # Remove the given index from the table.
@@ -134,4 +134,4 @@ def add_column_options!(sql, options) #:nodoc:
       end
     end
   end
-end
+end
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