Correctly dump integer-like primary key with default nil

The PR #27384 changed integer-like primary key to be autoincrement
unless an explicit default. This means that integer-like primary key is
restored as autoincrement unless dumping the default nil explicitly.
We should dump integer-like primary key with default nil correctly.

1 files changed, 5 insertions, 10 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
index 7a277b8cfd..a06dd0f6b8 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
@@ -1,16 +1,7 @@
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
-      module ColumnDumper
-        def column_spec_for_primary_key(column)
-          spec = super
-          if [:integer, :bigint].include?(schema_type(column)) && !column.auto_increment?
-            spec[:default] ||= schema_default(column) || "nil"
-          end
-          spec[:unsigned] = "true" if column.unsigned?
-          spec
-        end
-
+      module ColumnDumper # :nodoc:
         def prepare_column_options(column)
           spec = super
           spec[:unsigned] = "true" if column.unsigned?
@@ -34,6 +25,10 @@ module ActiveRecord
             super && column.auto_increment?
           end
 
+          def explicit_primary_key_default?(column)
+            column.type == :integer && !column.auto_increment?
+          end
+
           def schema_type(column)
             if column.sql_type == "tinyblob"
               :blob