Bug#33016004: Problem when calling audit_log_filter_flush() in a prepared stmt

Followup fix.
initid.const_item may be changed by the called init function, thus
calling the deinit function may be done based on a bad value.
Fixed by saving the value of initid.const_item before calling the
init function and using this value to decide whether to call deinit.

Reviewed by: Gleb Shchepa <[email protected]>

Change-Id: I05a54916fc6c7c7f18b4268bf7eb2d5fd65bc409

Author: roylyseng

sql/item_func.cc

@@ -4341,8 +4341,9 @@ void udf_handler::cleanup() {
   if (thd->stmt_arena->is_stmt_prepare() && thd->stmt_arena->is_repreparing)
     return;
 
-  if (initid.const_item && u_d->func_deinit != nullptr) {
+  if (m_init_func_called && u_d->func_deinit != nullptr) {
     (*u_d->func_deinit)(&initid);
+    m_init_func_called = false;
   }
   DEBUG_SYNC(current_thd, "udf_handler_destroy_sync");
   free_handler();
@@ -4566,6 +4567,7 @@ bool udf_handler::call_init_func() {
     my_error(ER_CANT_INITIALIZE_UDF, MYF(0), u_d->name.str, init_msg_buff);
     return true;
   }
+  m_init_func_called = true;
   return false;
 }
 

sql/sql_udf.h

@@ -90,6 +90,8 @@ class udf_handler {
   uchar is_null{0};
   /// True when handler has been initialized and use count incremented
   bool m_initialized{false};
+  /// True when init function has been called
+  bool m_init_func_called{false};
   Item **args;
   Udf_args_extension m_args_extension; /**< A struct that holds the extension
                                           arguments for each UDF argument */