Fixed memory leak in item_sum.cc::report_cut_value_error()

Only affects DBUG builds

sql/item_sum.cc

@@ -3737,13 +3737,16 @@ static void report_cut_value_error(THD *thd, uint row_count, const char *fname)
 {
   size_t fn_len= strlen(fname);
   char *fname_upper= (char *) my_alloca(fn_len + 1);
-  fname_upper[fn_len]= 0;
-  for (; fn_len; fn_len--)
-    fname_upper[fn_len-1]= my_toupper(&my_charset_latin1, fname[fn_len-1]);
+  if (!fname_upper)
+    fname_upper= (char*) fname;                 // Out of memory
+  else
+    memcpy(fname_upper, fname, fn_len+1);
+  my_caseup_str(&my_charset_latin1, fname_upper);
   push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
                       ER_CUT_VALUE_GROUP_CONCAT,
                       ER_THD(thd, ER_CUT_VALUE_GROUP_CONCAT),
                       row_count, fname_upper);
+  my_afree(fname_upper);
 }