`rename_table` renames primary key index name

Formerly, `rename_table` only renamed primary key index name if the
column's data type was sequential (serial, etc in PostgreSQL). The
problem with that is tables whose primary keys had other data types
(e.g. UUID) maintained the old primary key name. So for example,
if the `cats` table has a UUID primary key, and the table is renamed to
`felines`, the primary key index will still be called `cats_pkey`
instead of `felines_pkey`. This PR corrects it.

2 files changed, 28 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 3eff9e2f83..55566f1e34 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -377,14 +377,15 @@ module ActiveRecord
           clear_cache!
           execute "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
           pk, seq = pk_and_sequence_for(new_name)
-          if seq && seq.identifier == "#{table_name}_#{pk}_seq"
-            new_seq = "#{new_name}_#{pk}_seq"
+          if pk
             idx = "#{table_name}_pkey"
             new_idx = "#{new_name}_pkey"
-            execute "ALTER TABLE #{seq.quoted} RENAME TO #{quote_table_name(new_seq)}"
             execute "ALTER INDEX #{quote_table_name(idx)} RENAME TO #{quote_table_name(new_idx)}"
+            if seq && seq.identifier == "#{table_name}_#{pk}_seq"
+              new_seq = "#{new_name}_#{pk}_seq"
+              execute "ALTER TABLE #{seq.quoted} RENAME TO #{quote_table_name(new_seq)}"
+            end
           end
-
           rename_table_indexes(table_name, new_name)
         end
 
diff --git a/activerecord/test/cases/migration/rename_table_test.rb b/activerecord/test/cases/migration/rename_table_test.rb
index 7bcabd0cc6..5da3ad33a3 100644
--- a/activerecord/test/cases/migration/rename_table_test.rb
+++ b/activerecord/test/cases/migration/rename_table_test.rb
@@ -79,10 +79,33 @@ module ActiveRecord
           assert_equal ConnectionAdapters::PostgreSQL::Name.new("public", "octopi_#{pk}_seq"), seq
         end
 
+        def test_renaming_table_renames_primary_key
+          connection.create_table :cats, id: :uuid, default: "uuid_generate_v4()"
+          rename_table :cats, :felines
+
+          assert connection.table_exists? :felines
+          refute connection.table_exists? :cats
+
+          primary_key_name = connection.select_values(<<-SQL.strip_heredoc, "SCHEMA")[0]
+            SELECT c.relname
+              FROM pg_class c
+              JOIN pg_index i
+                ON c.oid = i.indexrelid
+             WHERE i.indisprimary
+               AND i.indrelid = 'felines'::regclass
+          SQL
+
+          assert_equal "felines_pkey", primary_key_name
+        ensure
+          connection.drop_table :cats, if_exists: true
+          connection.drop_table :felines, if_exists: true
+        end
+
         def test_renaming_table_doesnt_attempt_to_rename_non_existent_sequences
           connection.create_table :cats, id: :uuid, default: "uuid_generate_v4()"
           assert_nothing_raised { rename_table :cats, :felines }
           assert connection.table_exists? :felines
+          refute connection.table_exists? :cats
         ensure
           connection.drop_table :cats, if_exists: true
           connection.drop_table :felines, if_exists: true