PG::Result: Initialize all caches before freeze

Multiple Ractor instances could otherwise initialize them simultanly, leading to data races.

Author: larskanis

ext/pg_result.c

@@ -12,6 +12,7 @@ static VALUE sym_symbol, sym_string, sym_static_symbol;
 static VALUE pgresult_type_map_set( VALUE, VALUE );
 static t_pg_result *pgresult_get_this( VALUE );
 static t_pg_result *pgresult_get_this_safe( VALUE );
+static void ensure_init_for_tuple(VALUE self);
 
 #if defined(HAVE_PQRESULTMEMORYSIZE)
 
@@ -396,6 +397,7 @@ pg_result_freeze(VALUE self)
 {
 	t_pg_result *this = pgresult_get_this(self);
 
+	ensure_init_for_tuple(self);
 	RB_OBJ_WRITE(self, &this->connection, Qnil);
 	return rb_call_super(0, NULL);
 }