1 files changed, 39 insertions, 0 deletions
diff --git a/sql/item.cc b/sql/item.cc
index 883c293f645..04c75107d14 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -3161,6 +3161,45 @@ void Item_param::print(String *str, enum_query_type query_type)
 }
 
 
+/**
+  Preserve the original parameter types and values
+  when re-preparing a prepared statement.
+
+  Copy parameter type information and conversion function
+  pointers from a parameter of the old statement to the
+  corresponding parameter of the new one.
+
+  Move parameter values from the old parameters to the new
+  one. We simply "exchange" the values, which allows
+  to save on allocation and character set conversion in
+  case a parameter is a string or a blob/clob.
+
+  @param[in]  src   parameter item of the original
+                    prepared statement
+*/
+
+void
+Item_param::set_param_type_and_swap_value(Item_param *src)
+{
+  unsigned_flag= src->unsigned_flag;
+  param_type= src->param_type;
+  set_param_func= src->set_param_func;
+  item_type= src->item_type;
+  item_result_type= src->item_result_type;
+
+  collation.set(src->collation.collation);
+  maybe_null= src->maybe_null;
+  null_value= src->null_value;
+  max_length= src->max_length;
+  decimals= src->decimals;
+  state= src->state;
+  value= src->value;
+
+  decimal_value.swap(src->decimal_value);
+  str_value.swap(src->str_value);
+  str_value_ptr.swap(src->str_value_ptr);
+}
+
 /****************************************************************************
   Item_copy_string
 ****************************************************************************/