commit cac4c325f17b724825c0b3850cfc268df0a9710a
Author: GAO Xiaoxin <dennis.gao@greatopensource.com>
Date:   Tue Mar 24 19:05:31 2020 +0800

    Bug #99051 XA commit may do engine commit before MYSQL_BIN_LOG::ordered_commit
    
    -Description:
    
    In ubuntu 18.04 the xa commit operation may do a engine commit before binlog flush.
    
    If "xa commit" is done on the xid from "xa recover", it may invoke the function ha_commit_or_rollback_by_xid, which will invoke plugin_foreach_with_mask to loop all engine plugins to do xacommit_handlerton.
    
    In ubuntu 16.04, the binlog plugin will be invoked before innodb plugin, so the MYSQL_BIN_LOG::ordered_commit will be done before innobase_commit_by_xid. The binlog will be sync to disk first.
    
    But in ubuntu 18.04, the innodb plugin will be invoked before binlog plugin, if mysql crash after innobase_commit_by_xid and before MYSQL_BIN_LOG::ordered_commit, the innodb engine will in-consistence with the binlog file, which will lead replication broken.
    
    For detail, plugin_foreach_with_mask function may generate different sequence for plugins in ubuntu 16.04 and ubuntu 18.04.
    And the innodb plugin may be before binlog plugin.
    
    -How to repeat:
    
    Do the following test on Ubuntu 18.04 (can use docker image: "FROM ubuntu:18.04")
    
    In mysql5.7.25 (5.7.29 has the same problem), and use the following compile command:
    
    cmake  -DDOWNLOAD_BOOST=1 -DWITH_BOOST=`pwd`/../boost  -DCMAKE_INSTALL_PREFIX=`pwd`/../install_debug   -DWITH_INNODB_MEMCACHED=ON ..
    
    compile and install mysql, then do the following test by using gdb.
    
    Add a break-point at the beginning of MYSQL_BIN_LOG::ordered_commit, then execute the following sql:
    
    mysql> xa start '1';
    mysql> insert into t1 values (1);
    mysql> xa end '1';
    mysql> xa prepare '1';
    mysql> quit
    
    then login again execute:
    
    mysql> xa commit '1';  //-------> blocked by gdb
    
    quit the gdb to simulate the mysql crash, and start-up again.
    
    mysql> select * from t1;
    
    we will find the "1" has been inserted, but in binlog, there is no related "xa commit" event.
    
    -Suggested fix:
    
    Adjust the sequence in plugin_foreach_with_mask  to ensue the generated plugins vector will always put the binlog plugin in the first.

diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index 6ed656f..744c4ff 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -1642,6 +1642,10 @@ bool plugin_register_dynamic_and_init_all(int *argc,
   if (!initialized)
     DBUG_RETURN(true);
 
+  size_t total_plugin = plugin_hash[1].records;
+  size_t idx = 0;
+  struct st_plugin_int *plugin_tmp = NULL;
+
   /* Allocate the temporary mem root, will be freed before returning */
   MEM_ROOT tmp_root;
   init_alloc_root(key_memory_plugin_init_tmp, &tmp_root, 4096, 4096);
@@ -1669,6 +1673,16 @@ bool plugin_register_dynamic_and_init_all(int *argc,
 end:
   free_root(&tmp_root, MYF(0));
 
+  for (idx= 0; idx < total_plugin; idx++)
+  {
+    plugin_tmp = (st_plugin_int *) my_hash_element(&plugin_hash[1], idx);
+    if (!my_strcasecmp(&my_charset_latin1, plugin_tmp->name.str, "binlog"))
+    {
+      plugin_tmp->binlog_plugin = true;
+    } else
+      plugin_tmp->binlog_plugin = false;
+  }
+
   DBUG_RETURN(0);
 
 err:
@@ -2492,10 +2506,23 @@ bool plugin_foreach_with_mask(THD *thd, plugin_foreach_func **funcs,
   else
   {
     HASH *hash= plugin_hash + type;
+    bool has_binlog_plugin = false;
+    size_t binlog_pos = 0;
     for (idx= 0; idx < total; idx++)
     {
       plugin= (st_plugin_int *) my_hash_element(hash, idx);
       plugins[idx]= !(plugin->state & state_mask) ? plugin : NULL;
+      if (plugins[idx] && !has_binlog_plugin && plugins[idx]->binlog_plugin)
+      {
+        has_binlog_plugin = true;
+        binlog_pos = idx;
+      }
+    }
+    if (has_binlog_plugin && binlog_pos != 0)
+    {
+      st_plugin_int *tmp = plugins[0];
+      plugins[0] = plugins[binlog_pos];
+      plugins[binlog_pos] = tmp;
     }
   }
   mysql_mutex_unlock(&LOCK_plugin);
diff --git a/sql/sql_plugin_ref.h b/sql/sql_plugin_ref.h
index 89709d9..51caa19 100644
--- a/sql/sql_plugin_ref.h
+++ b/sql/sql_plugin_ref.h
@@ -46,6 +46,7 @@ struct st_plugin_int
   MEM_ROOT mem_root;            /* memory for dynamic plugin structures */
   sys_var *system_vars;         /* server variables for this plugin */
   enum_plugin_load_option load_option; /* OFF, ON, FORCE, F+PERMANENT */
+  bool binlog_plugin;
 };
 
 /*