Fix copying migrations from engines

There was a bug in ActiveRecord::Migration.copy method, which
prevented adding special comment about the origin of migration.

Because of that, the check if migration is identical or if it's
not and should be skipped was always saying that migration is
skipped, which was causing additional useless warnings about
skipped migrations.

1 files changed, 3 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index e53d5e7167..1d450da006 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -461,11 +461,11 @@ module ActiveRecord
         source_migrations = ActiveRecord::Migrator.migrations(path)
 
         source_migrations.each do |migration|
-          source = File.read(migration.filename)
+          source = File.read(migration.filename).chomp
           source = "# This migration comes from #{name} (originally #{migration.version})\n#{source}"
 
           if duplicate = destination_migrations.detect { |m| m.name == migration.name }
-            options[:on_skip].call(name, migration) if File.read(duplicate.filename) != source && options[:on_skip]
+            options[:on_skip].call(name, migration) if File.read(duplicate.filename).chomp != source && options[:on_skip]
             next
           end
 
@@ -474,7 +474,7 @@ module ActiveRecord
           old_path, migration.filename = migration.filename, new_path
           last = migration
 
-          FileUtils.cp(old_path, migration.filename)
+          File.open(migration.filename, "w") { |f| f.write source }
           copied << migration
           options[:on_copy].call(name, migration, old_path) if options[:on_copy]
           destination_migrations << migration