MDEV-36714: Rows_log_event::write_data_header overallocates buffer size

bnestere · bnestere · commit 88cc11dc54b5 · 2025-05-01T08:45:44.000-06:00
Nothing is broken by this, but the function
Rows_log_event::write_data_header
slightly over-allocates its buf by 2 bytes. It allocates 10
(ROWS_HEADER_LEN_V2), but only 8 are ever written.

This patch fixes the buf size to match what is written (i.e.
ROWS_HEADER_LEN_V1, or 8 bytes).

Reviewed By:
============
Kristian Nielsen &lt;knielsen@knielsen-hq.org&gt;
diff --git a/sql/log_event_server.cc b/sql/log_event_server.cc
@@ -5514,7 +5514,7 @@ Rows_log_event::do_update_pos(rpl_group_info *rgi)
 
 bool Rows_log_event::write_data_header(Log_event_writer *writer)
 {
-  uchar buf[ROWS_HEADER_LEN_V2];        // No need to init the buffer
+  uchar buf[ROWS_HEADER_LEN_V1];        // No need to init the buffer
   DBUG_ASSERT(m_table_id != UINT32_MAX);
   DBUG_EXECUTE_IF("old_row_based_repl_4_byte_map_id_master",
                   {

Original file line number	Diff line number	Diff line change
`@@ -5514,7 +5514,7 @@ Rows_log_event::do_update_pos(rpl_group_info *rgi)`
`5514`	`5514`
`5515`	`5515`	`bool Rows_log_event::write_data_header(Log_event_writer *writer)`
`5516`	`5516`	`{`
`5517`		`- uchar buf[ROWS_HEADER_LEN_V2]; // No need to init the buffer`
	`5517`	`+ uchar buf[ROWS_HEADER_LEN_V1]; // No need to init the buffer`
`5518`	`5518`	`DBUG_ASSERT(m_table_id != UINT32_MAX);`
`5519`	`5519`	`DBUG_EXECUTE_IF("old_row_based_repl_4_byte_map_id_master",`
`5520`	`5520`	`{`