SQLServer does not support changing the type of an indexed column (#12713).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11097 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/091_change_changesets_revision_to_string.rb

@@ -1,9 +1,13 @@
 class ChangeChangesetsRevisionToString < ActiveRecord::Migration
   def self.up
+    remove_index  :changesets, :name => :changesets_repos_rev
     change_column :changesets, :revision, :string, :null => false
+    add_index :changesets, [:repository_id, :revision], :unique => true, :name => :changesets_repos_rev
   end
 
   def self.down
+    remove_index  :changesets, :name => :changesets_repos_rev
     change_column :changesets, :revision, :integer, :null => false
+    add_index :changesets, [:repository_id, :revision], :unique => true, :name => :changesets_repos_rev
   end
 end