MDEV-6703 Add "mysqlbinlog --binlog-row-event-max-size" support

partially cherry-pick from mysql/5.6.
No test case (mysql/5.6 test case is useless, the correct
test case uses too much memory)

commit e061985813db54948f99892d89f7e076242473a5
Author:  <Dao-Gang.Qu@sun.com>
Date:   Tue Jun 1 15:02:22 2010 +0800

    Bug #49931          Incorrect type in read_log_event error
    Bug #49932          mysqlbinlog max_allowed_packet hard coded to 1GB

Author: vuvova

client/mysqlbinlog.cc

@@ -49,6 +49,8 @@
 
 #include "mysqld.h"
 
+#include <algorithm>
+
 Rpl_filter *binlog_filter= 0;
 
 #define BIN_LOG_HEADER_SIZE	4
@@ -67,6 +69,7 @@ ulong server_id = 0;
 ulong bytes_sent = 0L, bytes_received = 0L;
 ulong mysqld_net_retry_count = 10L;
 ulong open_files_limit;
+ulong opt_binlog_rows_event_max_size;
 uint test_flags = 0; 
 static uint opt_protocol= 0;
 static FILE *result_file;
@@ -1436,6 +1439,12 @@ that may lead to an endless loop.",
    "Used to reserve file descriptors for use by this program.",
    &open_files_limit, &open_files_limit, 0, GET_ULONG,
    REQUIRED_ARG, MY_NFILE, 8, OS_FILE_LIMIT, 0, 1, 0},
+  {"binlog-row-event-max-size", 0,
+   "The maximum size of a row-based binary log event in bytes. Rows will be "
+   "grouped into events smaller than this size if possible. "
+   "This value must be a multiple of 256.",
+   &opt_binlog_rows_event_max_size, &opt_binlog_rows_event_max_size, 0,
+   GET_ULONG, REQUIRED_ARG, UINT_MAX,  256, ULONG_MAX,  0, 256,  0},
   {"verify-binlog-checksum", 'c', "Verify checksum binlog events.",
    (uchar**) &opt_verify_binlog_checksum, (uchar**) &opt_verify_binlog_checksum,
    0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},

sql/log_event.cc

@@ -52,6 +52,8 @@
 
 #define my_b_write_string(A, B) my_b_write((A), (B), (uint) (sizeof(B) - 1))
 
+using std::max;
+
 /**
   BINLOG_CHECKSUM variable.
 */
@@ -1326,9 +1328,10 @@ int Log_event::read_log_event(IO_CACHE* file, String* packet,
   }
   data_len= uint4korr(buf + EVENT_LEN_OFFSET);
   if (data_len < LOG_EVENT_MINIMAL_HEADER_LEN ||
-      data_len > current_thd->variables.max_allowed_packet)
+      data_len > max(current_thd->variables.max_allowed_packet,
+                     opt_binlog_rows_event_max_size + MAX_LOG_EVENT_HEADER))
   {
-    DBUG_PRINT("error",("data_len: %ld", data_len));
+    DBUG_PRINT("error",("data_len: %lu", data_len));
     result= ((data_len < LOG_EVENT_MINIMAL_HEADER_LEN) ? LOG_READ_BOGUS :
 	     LOG_READ_TOO_LARGE);
     goto end;
@@ -1449,7 +1452,7 @@ failed my_b_read"));
     */
     DBUG_RETURN(0);
   }
-  uint data_len = uint4korr(head + EVENT_LEN_OFFSET);
+  ulong data_len = uint4korr(head + EVENT_LEN_OFFSET);
   char *buf= 0;
   const char *error= 0;
   Log_event *res=  0;
@@ -1458,7 +1461,8 @@ failed my_b_read"));
   uint max_allowed_packet= thd ? slave_max_allowed_packet:~(uint)0;
 #endif
 
-  if (data_len > max_allowed_packet)
+  if (data_len > max<ulong>(max_allowed_packet,
+                        opt_binlog_rows_event_max_size + MAX_LOG_EVENT_HEADER))
   {
     error = "Event too big";
     goto err;
@@ -1492,7 +1496,7 @@ failed my_b_read"));
   {
     DBUG_ASSERT(error != 0);
     sql_print_error("Error in Log_event::read_log_event(): "
-                    "'%s', data_len: %d, event_type: %d",
+                    "'%s', data_len: %lu, event_type: %d",
 		    error,data_len,(uchar)(head[EVENT_TYPE_OFFSET]));
     my_free(buf);
     /*