BUG#34141: mysqlbinlog cannot read 4.1 binlogs containing load data infile

Main problem: mysql 5.1 cannot read binlogs from 4.1.
Subproblem 1: There is a mistake in sql_ex_info::init. The read_str()
function updates its first argument to point to the next character to
read. However, it is applied only to a copy of the buffer pointer, so the
real buffer pointer is not updated.
Fix 1: do not take a copy of the buffer pointer. The copy was needed
because sql_ex_info::init does not use the const attribute on some of its
arguments. So we add the const attribute, too.
Subproblem 2: The first BINLOG statement is asserted to be a
FORMAT_DESCRIPTION_LOG_EVENT, but 4.1 binlogs begin with START_EVENT_V3.
Fix 2: allow START_EVENT_V3 too.

1 files changed, 3 insertions, 4 deletions

diff --git a/sql/sql_binlog.cc b/sql/sql_binlog.cc
index 543b1af9fc0..778aa46149c 100644
--- a/sql/sql_binlog.cc
+++ b/sql/sql_binlog.cc
@@ -159,14 +159,13 @@ void mysql_client_binlog_statement(THD* thd)
       */
       if (!have_fd_event)
       {
-        if (bufptr[EVENT_TYPE_OFFSET] == FORMAT_DESCRIPTION_EVENT)
+        int type = bufptr[EVENT_TYPE_OFFSET];
+        if (type == FORMAT_DESCRIPTION_EVENT || type == START_EVENT_V3)
           have_fd_event= TRUE;
         else
         {
           my_error(ER_NO_FORMAT_DESCRIPTION_EVENT_BEFORE_BINLOG_STATEMENT,
-                   MYF(0),
-                   Log_event::get_type_str(
-                     (Log_event_type)bufptr[EVENT_TYPE_OFFSET]));
+                   MYF(0), Log_event::get_type_str((Log_event_type)type));
           goto end;
         }
       }