1 files changed, 59 insertions, 0 deletions
diff --git a/config/initializers/ar5_pg_10_support.rb b/config/initializers/ar5_pg_10_support.rb
new file mode 100644
index 00000000000..a529c74a8ce
--- /dev/null
+++ b/config/initializers/ar5_pg_10_support.rb
@@ -0,0 +1,59 @@
+raise "Vendored ActiveRecord 5 code! Delete #{__FILE__}!" if ActiveRecord::VERSION::MAJOR >= 5
+
+if Gitlab::Database.postgresql?
+  require 'active_record/connection_adapters/postgresql_adapter'
+  require 'active_record/connection_adapters/postgresql/schema_statements'
+
+  #
+  # Monkey-patch the refused Rails 4.2 patch at https://github.com/rails/rails/pull/31330
+  #
+  # Updates sequence logic to support PostgreSQL 10.
+  #
+  # rubocop:disable all
+  module ActiveRecord
+    module ConnectionAdapters
+
+      # We need #postgresql_version to be public as in ActiveRecord 5 for seed_fu
+      # to work. In ActiveRecord 4, it is protected.
+      # https://github.com/mbleigh/seed-fu/issues/123
+      class PostgreSQLAdapter
+        public :postgresql_version
+      end
+
+      module PostgreSQL
+        module SchemaStatements
+          # Resets the sequence of a table's primary key to the maximum value.
+          def reset_pk_sequence!(table, pk = nil, sequence = nil) #:nodoc:
+            unless pk and sequence
+              default_pk, default_sequence = pk_and_sequence_for(table)
+
+              pk ||= default_pk
+              sequence ||= default_sequence
+            end
+
+            if @logger && pk && !sequence
+              @logger.warn "#{table} has primary key #{pk} with no default sequence"
+            end
+
+            if pk && sequence
+              quoted_sequence = quote_table_name(sequence)
+              max_pk = select_value("SELECT MAX(#{quote_column_name pk}) FROM #{quote_table_name(table)}")
+              if max_pk.nil?
+                if postgresql_version >= 100000
+                  minvalue = select_value("SELECT seqmin FROM pg_sequence WHERE seqrelid = #{quote(quoted_sequence)}::regclass")
+                else
+                  minvalue = select_value("SELECT min_value FROM #{quoted_sequence}")
+                end
+              end
+
+              select_value <<-end_sql, 'SCHEMA'
+                SELECT setval(#{quote(quoted_sequence)}, #{max_pk ? max_pk : minvalue}, #{max_pk ? true : false})
+              end_sql
+            end
+          end
+        end
+      end
+    end
+  end
+  # rubocop:enable all
+end