Sqlite preserves primary keys when copying/altering tables.

Backport #2312.
Fixes #9367.

I also added a test-case to make sure that renaming or removing
a column preserves the primary key.

2 files changed, 22 insertions, 0 deletions

diff --git a/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb b/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb
index 575b4806c1..74288a98d1 100644
--- a/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/copy_table_test.rb
@@ -57,6 +57,14 @@ class CopyTableTest < ActiveRecord::TestCase
     end
   end
 
+  def test_copy_table_with_unconventional_primary_key
+    test_copy_table('owners', 'owners_unconventional') do |from, to, options|
+      original_pk = @connection.primary_key('owners')
+      copied_pk = @connection.primary_key('owners_unconventional')
+      assert_equal original_pk, copied_pk
+    end
+  end
+
 protected
   def copy_table(from, to, options = {})
     @connection.copy_table(from, to, {:temporary => true}.merge(options))
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 7bb71b7b6e..5b67d22c31 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -889,6 +889,20 @@ if ActiveRecord::Base.connection.supports_migrations?
       ActiveRecord::Base.connection.drop_table(:hats) rescue nil
     end
 
+    def test_removing_and_renaming_column_preserves_custom_primary_key
+      ActiveRecord::Base.connection.create_table "my_table", :primary_key => "my_table_id", :force => true do |t|
+        t.integer "col_one"
+        t.string "col_two", :limit => 128, :null => false
+      end
+
+      ActiveRecord::Base.connection.remove_column("my_table", "col_two")
+      ActiveRecord::Base.connection.rename_column("my_table", "col_one", "col_three")
+
+      assert_equal 'my_table_id', ActiveRecord::Base.connection.primary_key('my_table')
+    ensure
+      ActiveRecord::Base.connection.drop_table(:my_table) rescue nil
+    end
+
     def test_change_type_of_not_null_column
       assert_nothing_raised do
         Topic.connection.change_column "topics", "written_on", :datetime, :null => false