MDEV-31646 untie from max_allowed_packet and opt_binlog_rows_event_max_size

sql/log_event.cc

@@ -761,17 +761,13 @@ Log_event::Log_event(const uchar *buf,
 
 int Log_event::read_log_event(IO_CACHE* file, String* packet,
                               const Format_description_log_event *fdle,
-                              enum enum_binlog_checksum_alg checksum_alg_arg)
+                              enum enum_binlog_checksum_alg checksum_alg_arg,
+                              size_t max_allowed_packet)
 {
   ulong data_len;
   char buf[LOG_EVENT_MINIMAL_HEADER_LEN];
   uchar ev_offset= packet->length();
-#if !defined(MYSQL_CLIENT)
-  THD *thd=current_thd;
-  ulong max_allowed_packet= thd ? thd->slave_thread ? slave_max_allowed_packet
-                                                    : thd->variables.max_allowed_packet
-                                : ~(uint)0;
-#endif
+
   DBUG_ENTER("Log_event::read_log_event(IO_CACHE*,String*...)");
 
   if (my_b_read(file, (uchar*) buf, sizeof(buf)))
@@ -882,7 +878,8 @@ int Log_event::read_log_event(IO_CACHE* file, String* packet,
 
 Log_event* Log_event::read_log_event(IO_CACHE* file,
                                      const Format_description_log_event *fdle,
-                                     my_bool crc_check)
+                                     my_bool crc_check,
+                                     size_t max_allowed_packet)
 {
   DBUG_ENTER("Log_event::read_log_event(IO_CACHE*,Format_description_log_event*...)");
   DBUG_ASSERT(fdle != 0);
@@ -890,7 +887,8 @@ Log_event* Log_event::read_log_event(IO_CACHE* file,
   const char *error= 0;
   Log_event *res= 0;
 
-  switch (read_log_event(file, &event, fdle, BINLOG_CHECKSUM_ALG_OFF))
+  switch (read_log_event(file, &event, fdle, BINLOG_CHECKSUM_ALG_OFF,
+                         max_allowed_packet))
   {
     case 0:
       break;

sql/log_event.h

@@ -1363,6 +1363,20 @@ class Log_event
 #endif
 #endif
 
+private:
+  static size_t get_max_packet()
+  {
+    size_t max_packet= ~0UL;
+#if !defined(MYSQL_CLIENT)
+    THD *thd=current_thd;
+    if (thd)
+      max_packet= thd->slave_thread ? slave_max_allowed_packet
+                                    : thd->variables.max_allowed_packet;
+#endif
+    return max_packet;
+  }
+public:
+
   /*
     read_log_event() functions read an event from a binlog or relay
     log; used by SHOW BINLOG EVENTS, the binlog_dump thread on the
@@ -1377,7 +1391,15 @@ class Log_event
   static Log_event* read_log_event(IO_CACHE* file,
                                    const Format_description_log_event
                                    *description_event,
-                                   my_bool crc_check);
+                                   my_bool crc_check,
+                                   size_t max_allowed_packet);
+  static Log_event* read_log_event(IO_CACHE* file,
+                                   const Format_description_log_event
+                                   *description_event,
+                                   my_bool crc_check)
+  {
+    return read_log_event(file, description_event, crc_check, get_max_packet());
+  }
 
   /**
     Reads an event from a binlog or relay log. Used by the dump thread
@@ -1404,7 +1426,16 @@ class Log_event
    */
   static int read_log_event(IO_CACHE* file, String* packet,
                             const Format_description_log_event *fdle,
-                            enum enum_binlog_checksum_alg checksum_alg_arg);
+                            enum enum_binlog_checksum_alg checksum_alg_arg,
+                            size_t max_allowed_packet);
+
+  static int read_log_event(IO_CACHE* file, String* packet,
+                            const Format_description_log_event *fdle,
+                            enum enum_binlog_checksum_alg checksum_alg)
+  {
+    return read_log_event(file, packet, fdle, checksum_alg, get_max_packet());
+  }
+
   /* 
      The value is set by caller of FD constructor and
      Log_event::write_header() for the rest.

sql/sql_table.cc

@@ -11665,7 +11665,7 @@ static int online_alter_read_from_binlog(THD *thd, rpl_group_info *rgi,
   do
   {
     const auto *descr_event= rgi->rli->relay_log.description_event_for_exec;
-    auto *ev= Log_event::read_log_event(log_file, descr_event, false);
+    auto *ev= Log_event::read_log_event(log_file, descr_event, false, ~0UL);
     error= log_file->error;
     if (unlikely(!ev))
     {