Fix dbug crash in mysql_server_end

unittest/libmariadb/thread.c

@@ -0,0 +1,60 @@
+/*
+*/
+
+#include "my_test.h"
+
+static int basic_connect(MYSQL *mysql)
+{
+  MYSQL_ROW row;
+  MYSQL_RES *res;
+  MYSQL_FIELD *field;
+  int rc;
+
+  MYSQL *my= mysql_init(NULL);
+  FAIL_IF(!my, "mysql_init() failed");
+
+  FAIL_IF(!mysql_real_connect(my, hostname, username, password, schema,
+                         port, socketname, 0), mysql_error(my));
+
+  rc= mysql_query(my, "SELECT @@version");
+  check_mysql_rc(rc, my);
+
+  res= mysql_store_result(my);
+  field= mysql_fetch_fields(res);
+  FAIL_IF(!res, mysql_error(my));
+
+  while ((row= mysql_fetch_row(res)) != NULL)
+  {
+    FAIL_IF(mysql_num_fields(res) != 1, "Got the wrong number of fields");
+  }
+  FAIL_IF(mysql_errno(my), mysql_error(my));
+
+  mysql_free_result(res);
+  mysql_close(my);
+
+  return OK;
+}
+
+struct my_tests_st my_tests[] = {
+  {"basic_connect", basic_connect, TEST_CONNECTION_NONE, 0,  NULL,  NULL},
+  {NULL, NULL, 0, 0, NULL, NULL}
+};
+
+
+int main(int argc, char **argv)
+{
+
+  mysql_library_init(0,0,NULL);
+  mysql_thread_init();
+  mysql_thread_end();
+  mysql_library_end();
+
+  if (argc > 1)
+    get_options(argc, argv);
+
+  get_envvars();
+
+  run_tests(my_tests);
+
+  return(exit_status());
+}