gistfile1.diff

diff --git a/ext/mysql2/client.c b/ext/mysql2/client.c
index 258f3fb..57f49de 100644
--- a/ext/mysql2/client.c
+++ b/ext/mysql2/client.c
@@ -17,8 +17,10 @@ static ID intern_merge, intern_error_number_eql, intern_sql_state_eql;
   rb_iv_set(conn, "@active", Qfalse);
 
 #define GET_CLIENT(self) \
+  mysql_client_wrapper * wrapper; \
   MYSQL * client; \
-  Data_Get_Struct(self, MYSQL, client);
+  Data_Get_Struct(self, mysql_client_wrapper, wrapper); \
+  client = &wrapper->client;
 
 /*
  * used to pass all arguments to mysql_real_connect while inside
@@ -66,6 +68,13 @@ struct nogvl_send_query_args {
  * - mysql_ssl_set()
  */
 
+static void rb_mysql_client_mark(void * wrapper) {
+  mysql_client_wrapper * w = wrapper;
+  if (w) {
+    rb_gc_mark(w->encoding);
+  }
+}
+
 static VALUE rb_raise_mysql2_error(MYSQL *client) {
   VALUE e = rb_exc_new2(cMysql2Error, mysql_error(client));
   rb_funcall(e, intern_error_number_eql, 1, INT2NUM(mysql_errno(client)));
@@ -96,7 +105,8 @@ static VALUE nogvl_connect(void *ptr) {
 }
 
 static void rb_mysql_client_free(void * ptr) {
-  MYSQL * client = (MYSQL *)ptr;
+  mysql_client_wrapper * wrapper = (mysql_client_wrapper *)ptr;
+  MYSQL * client = &wrapper->client;
 
   /*
    * we'll send a QUIT message to the server, but that message is more of a
@@ -129,15 +139,11 @@ static VALUE nogvl_close(void * ptr) {
 }
 
 static VALUE allocate(VALUE klass) {
-  MYSQL * client;
-
-  return Data_Make_Struct(
-      klass,
-      MYSQL,
-      NULL,
-      rb_mysql_client_free,
-      client
-  );
+  VALUE obj;
+  mysql_client_wrapper * wrapper;
+  obj = Data_Make_Struct(klass, mysql_client_wrapper, rb_mysql_client_mark, rb_mysql_client_free, wrapper);
+  wrapper->encoding = Qnil;
+  return obj;
 }
 
 static VALUE rb_connect(VALUE self, VALUE user, VALUE pass, VALUE host, VALUE port, VALUE database, VALUE socket) {
diff --git a/ext/mysql2/client.h b/ext/mysql2/client.h
index a962303..a520b2e 100644
--- a/ext/mysql2/client.h
+++ b/ext/mysql2/client.h
@@ -31,4 +31,9 @@ rb_thread_blocking_region(
 
 void init_mysql2_client();
 
+typedef struct {
+  VALUE encoding;
+  MYSQL client;
+} mysql_client_wrapper;
+
 #endif
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