Merge pull request #27389 from kamipo/fix_mysql_pk_dumping_correctly

Restore the behaviour of the compatibility layer for integer-like PKs

* kamipo/fix_mysql_pk_dumping_correctly:
  Restore custom primary key tests lost at #26266
  Restore the behaviour of the compatibility layer for integer-like PKs
  Correctly dump integer-like primary key with default nil

1 files changed, 6 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
index f0f4b5e565..34036d8a1d 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
@@ -14,6 +14,8 @@ module ActiveRecord
         return {} if default_primary_key?(column)
         spec = { id: schema_type(column).inspect }
         spec.merge!(prepare_column_options(column).except!(:null))
+        spec[:default] ||= "nil" if explicit_primary_key_default?(column)
+        spec
       end
 
       # This can be overridden on an Adapter level basis to support other
@@ -60,6 +62,10 @@ module ActiveRecord
           schema_type(column) == :bigint
         end
 
+        def explicit_primary_key_default?(column)
+          false
+        end
+
         def schema_type_with_virtual(column)
           if supports_virtual_columns? && column.virtual?
             :virtual