From a3348130fe1549d94b43ada59aef2a39ccefdbaa Mon Sep 17 00:00:00 2001
From: Max Lapshin <max@maxidoors.ru>
Date: Mon, 20 Apr 2009 19:47:31 +0400
Subject: [PATCH] Fixed dumping from postgresql columns in index in wrong order. Now it's ok.

---
 .../connection_adapters/postgresql_adapter.rb      |   35 +++++++++++---------
 activerecord/test/cases/schema_dumper_test.rb      |    5 +++
 activerecord/test/schema/schema.rb                 |    2 +
 3 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index ec204d0..05c804a 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -640,33 +640,36 @@ module ActiveRecord
       def indexes(table_name, name = nil)
          schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
          result = query(<<-SQL, name)
-           SELECT distinct i.relname, d.indisunique, a.attname
-             FROM pg_class t, pg_class i, pg_index d, pg_attribute a
+           SELECT distinct i.relname, d.indisunique, d.indkey, t.oid
+             FROM pg_class t, pg_class i, pg_index d
            WHERE i.relkind = 'i'
              AND d.indexrelid = i.oid
              AND d.indisprimary = 'f'
              AND t.oid = d.indrelid
              AND t.relname = '#{table_name}'
              AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname IN (#{schemas}) )
-             AND a.attrelid = t.oid
-             AND ( d.indkey[0]=a.attnum OR d.indkey[1]=a.attnum
-                OR d.indkey[2]=a.attnum OR d.indkey[3]=a.attnum
-                OR d.indkey[4]=a.attnum OR d.indkey[5]=a.attnum
-                OR d.indkey[6]=a.attnum OR d.indkey[7]=a.attnum
-                OR d.indkey[8]=a.attnum OR d.indkey[9]=a.attnum )
           ORDER BY i.relname
         SQL
+        
 
-        current_index = nil
         indexes = []
 
-        result.each do |row|
-          if current_index != row[0]
-            indexes << IndexDefinition.new(table_name, row[0], row[1] == "t", [])
-            current_index = row[0]
-          end
-
-          indexes.last.columns << row[2]
+        indexes = result.map do |row|
+          index_name = row[0]
+          unique = row[1] == 't'
+          indkey = row[2].split(" ")
+          oid = row[3]
+          
+          columns = query(<<-SQL, "Columns for index #{row[0]} on #{table_name}").inject({}) {|attlist, r| attlist[r[1]] = r[0]; attlist}
+          SELECT a.attname, a.attnum
+          FROM pg_attribute a
+          WHERE a.attrelid = #{oid}
+          AND a.attnum IN (#{indkey.join(",")})
+          SQL
+          
+          column_names = indkey.map {|attnum| columns[attnum] }
+          IndexDefinition.new(table_name, index_name, unique, column_names)
+          
         end
 
         indexes
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 17e4c75..6063742 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -146,6 +146,11 @@ class SchemaDumperTest < ActiveRecord::TestCase
       ActiveRecord::SchemaDumper.dump(ActiveRecord::Base.connection, stream)
     end
   end
+  
+  def test_schema_dumps_index_columns_in_right_order
+    index_definition = standard_dump.split(/\n/).grep(/add_index.*companies/).first.strip
+    assert_equal 'add_index "companies", ["firm_id", "type", "rating", "ruby_type"], :name => "company_index"', index_definition
+  end
 
   if current_adapter?(:MysqlAdapter)
     def test_schema_dump_should_not_add_default_value_for_mysql_text_field
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 5640510..3288abb 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -113,6 +113,8 @@ ActiveRecord::Schema.define do
     t.integer :client_of
     t.integer :rating, :default => 1
   end
+  
+  add_index :companies, [:firm_id, :type, :rating, :ruby_type], :name => "company_index"
 
   create_table :computers, :force => true do |t|
     t.integer :developer, :null => false
-- 
1.5.4.3