Never access thd->ha_data directly, use getters/setters from the plugin

API instead.
This is a pre-requisite of the fix for Bug 12713, which changes the
data type of thd->ha_data from void * to struct Ha_data.


include/mysql/plugin.h:
  Provide accessors to thd->ha_data for simple and robust code.
sql/ha_ndbcluster_binlog.h:
  Use getters/setters of thd->ha_data, instead of direct access.
sql/handler.cc:
  Use a getter of thd->ha_data instead of direct access.
sql/log.cc:
  Use getters/setters of thd->ha_data, instead of direct access.
sql/rpl_utility.h:
  Fix a compilation warning (declaration order must match initialization
  order in constructor).
storage/federated/ha_federated.cc:
  Use interface accessors to thd->ha_data, instead of direct access.

include/mysql/plugin.h

@@ -785,5 +785,28 @@ void mysql_query_cache_invalidate4(MYSQL_THD thd,
 }
 #endif
 
+#ifdef __cplusplus
+/**
+  Provide a handler data getter to simplify coding
+*/
+inline
+void *
+thd_get_ha_data(const MYSQL_THD thd, const struct handlerton *hton)
+{
+  return *thd_ha_data(thd, hton);
+}
+
+/**
+  Provide a handler data setter to simplify coding
+*/
+inline
+void
+thd_set_ha_data(const MYSQL_THD thd, const struct handlerton *hton,
+                const void *ha_data)
+{
+  *thd_ha_data(thd, hton)= (void*) ha_data;
+}
+#endif
+
 #endif
 

sql/ha_ndbcluster_binlog.h

@@ -216,10 +216,12 @@ inline void free_share(NDB_SHARE **share, bool have_lock= FALSE)
 
 inline
 Thd_ndb *
-get_thd_ndb(THD *thd) { return (Thd_ndb *) thd->ha_data[ndbcluster_hton->slot]; }
+get_thd_ndb(THD *thd)
+{ return (Thd_ndb *) thd_get_ha_data(thd, ndbcluster_hton); }
 
 inline
 void
-set_thd_ndb(THD *thd, Thd_ndb *thd_ndb) { thd->ha_data[ndbcluster_hton->slot]= thd_ndb; }
+set_thd_ndb(THD *thd, Thd_ndb *thd_ndb)
+{ thd_set_ha_data(thd, ndbcluster_hton, thd_ndb); }
 
 Ndb* check_ndb_in_thd(THD* thd);

sql/handler.cc

@@ -563,7 +563,7 @@ static my_bool closecon_handlerton(THD *thd, plugin_ref plugin,
     be rolled back already
   */
   if (hton->state == SHOW_OPTION_YES && hton->close_connection &&
-      thd->ha_data[hton->slot])
+      thd_get_ha_data(thd, hton))
     hton->close_connection(hton, thd);
   return FALSE;
 }
@@ -1511,7 +1511,7 @@ void handler::ha_statistic_increment(ulong SSV::*offset) const
 
 void **handler::ha_data(THD *thd) const
 {
-  return (void **) thd->ha_data + ht->slot;
+  return thd_ha_data(thd, ht);
 }
 
 THD *handler::ha_thd(void) const

sql/log.cc

@@ -1215,10 +1215,10 @@ binlog_trans_log_savepos(THD *thd, my_off_t *pos)
 {
   DBUG_ENTER("binlog_trans_log_savepos");
   DBUG_ASSERT(pos != NULL);
-  if (thd->ha_data[binlog_hton->slot] == NULL)
+  if (thd_get_ha_data(thd, binlog_hton) == NULL)
     thd->binlog_setup_trx_data();
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
   DBUG_ASSERT(mysql_bin_log.is_open());
   *pos= trx_data->position();
   DBUG_PRINT("return", ("*pos: %lu", (ulong) *pos));
@@ -1247,12 +1247,12 @@ binlog_trans_log_truncate(THD *thd, my_off_t pos)
   DBUG_ENTER("binlog_trans_log_truncate");
   DBUG_PRINT("enter", ("pos: %lu", (ulong) pos));
 
-  DBUG_ASSERT(thd->ha_data[binlog_hton->slot] != NULL);
+  DBUG_ASSERT(thd_get_ha_data(thd, binlog_hton) != NULL);
   /* Only true if binlog_trans_log_savepos() wasn't called before */
   DBUG_ASSERT(pos != ~(my_off_t) 0);
 
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
   trx_data->truncate(pos);
   DBUG_VOID_RETURN;
 }
@@ -1283,9 +1283,9 @@ int binlog_init(void *p)
 static int binlog_close_connection(handlerton *hton, THD *thd)
 {
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
   DBUG_ASSERT(trx_data->empty());
-  thd->ha_data[binlog_hton->slot]= 0;
+  thd_set_ha_data(thd, binlog_hton, NULL);
   trx_data->~binlog_trx_data();
   my_free((uchar*)trx_data, MYF(0));
   return 0;
@@ -1408,7 +1408,7 @@ static int binlog_commit(handlerton *hton, THD *thd, bool all)
 {
   DBUG_ENTER("binlog_commit");
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
 
   if (trx_data->empty())
   {
@@ -1435,7 +1435,7 @@ static int binlog_rollback(handlerton *hton, THD *thd, bool all)
   DBUG_ENTER("binlog_rollback");
   int error=0;
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
 
   if (trx_data->empty()) {
     trx_data->reset();
@@ -3252,23 +3252,22 @@ int THD::binlog_setup_trx_data()
 {
   DBUG_ENTER("THD::binlog_setup_trx_data");
   binlog_trx_data *trx_data=
-    (binlog_trx_data*) ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(this, binlog_hton);
 
   if (trx_data)
     DBUG_RETURN(0);                             // Already set up
 
-  ha_data[binlog_hton->slot]= trx_data=
-    (binlog_trx_data*) my_malloc(sizeof(binlog_trx_data), MYF(MY_ZEROFILL));
+  trx_data= (binlog_trx_data*) my_malloc(sizeof(binlog_trx_data), MYF(MY_ZEROFILL));
   if (!trx_data ||
       open_cached_file(&trx_data->trans_log, mysql_tmpdir,
                        LOG_PREFIX, binlog_cache_size, MYF(MY_WME)))
   {
     my_free((uchar*)trx_data, MYF(MY_ALLOW_ZERO_PTR));
-    ha_data[binlog_hton->slot]= 0;
     DBUG_RETURN(1);                      // Didn't manage to set it up
   }
+  thd_set_ha_data(this, binlog_hton, trx_data);
 
-  trx_data= new (ha_data[binlog_hton->slot]) binlog_trx_data;
+  trx_data= new (thd_get_ha_data(this, binlog_hton)) binlog_trx_data;
 
   DBUG_RETURN(0);
 }
@@ -3304,7 +3303,7 @@ int THD::binlog_setup_trx_data()
 void
 THD::binlog_start_trans_and_stmt()
 {
-  binlog_trx_data *trx_data= (binlog_trx_data*) ha_data[binlog_hton->slot];
+  binlog_trx_data *trx_data= (binlog_trx_data*) thd_get_ha_data(this, binlog_hton);
   DBUG_ENTER("binlog_start_trans_and_stmt");
   DBUG_PRINT("enter", ("trx_data: 0x%lx  trx_data->before_stmt_pos: %lu",
                        (long) trx_data,
@@ -3324,7 +3323,7 @@ THD::binlog_start_trans_and_stmt()
 
 void THD::binlog_set_stmt_begin() {
   binlog_trx_data *trx_data=
-    (binlog_trx_data*) ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(this, binlog_hton);
 
   /*
     The call to binlog_trans_log_savepos() might create the trx_data
@@ -3334,14 +3333,15 @@ void THD::binlog_set_stmt_begin() {
   */
   my_off_t pos= 0;
   binlog_trans_log_savepos(this, &pos);
-  trx_data= (binlog_trx_data*) ha_data[binlog_hton->slot];
+  trx_data= (binlog_trx_data*) thd_get_ha_data(this, binlog_hton);
   trx_data->before_stmt_pos= pos;
 }
 
 int THD::binlog_flush_transaction_cache()
 {
   DBUG_ENTER("binlog_flush_transaction_cache");
-  binlog_trx_data *trx_data= (binlog_trx_data*) ha_data[binlog_hton->slot];
+  binlog_trx_data *trx_data= (binlog_trx_data*)
+    thd_get_ha_data(this, binlog_hton);
   DBUG_PRINT("enter", ("trx_data=0x%lu", (ulong) trx_data));
   if (trx_data)
     DBUG_PRINT("enter", ("trx_data->before_stmt_pos=%lu",
@@ -3404,7 +3404,7 @@ Rows_log_event*
 THD::binlog_get_pending_rows_event() const
 {
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(this, binlog_hton);
   /*
     This is less than ideal, but here's the story: If there is no
     trx_data, prepare_pending_rows_event() has never been called
@@ -3417,11 +3417,11 @@ THD::binlog_get_pending_rows_event() const
 void
 THD::binlog_set_pending_rows_event(Rows_log_event* ev)
 {
-  if (ha_data[binlog_hton->slot] == NULL)
+  if (thd_get_ha_data(this, binlog_hton) == NULL)
     binlog_setup_trx_data();
 
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(this, binlog_hton);
 
   DBUG_ASSERT(trx_data);
   trx_data->set_pending(ev);
@@ -3444,7 +3444,7 @@ MYSQL_BIN_LOG::flush_and_set_pending_rows_event(THD *thd,
   int error= 0;
 
   binlog_trx_data *const trx_data=
-    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
 
   DBUG_ASSERT(trx_data);
 
@@ -3595,7 +3595,7 @@ bool MYSQL_BIN_LOG::write(Log_event *event_info)
         goto err;
 
       binlog_trx_data *const trx_data=
-        (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+        (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
       IO_CACHE *trans_log= &trx_data->trans_log;
       my_off_t trans_log_pos= my_b_tell(trans_log);
       if (event_info->get_cache_stmt() || trans_log_pos != 0)
@@ -5032,7 +5032,7 @@ int TC_LOG_BINLOG::log_xid(THD *thd, my_xid xid)
   DBUG_ENTER("TC_LOG_BINLOG::log");
   Xid_log_event xle(thd, xid);
   binlog_trx_data *trx_data=
-    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
+    (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
   /*
     We always commit the entire transaction when writing an XID. Also
     note that the return value is inverted.

sql/rpl_utility.h

@@ -241,8 +241,8 @@ class table_def
 private:
   ulong m_size;           // Number of elements in the types array
   field_type *m_type;                     // Array of type descriptors
-  uint16 *m_field_metadata;
   uint m_field_metadata_size;
+  uint16 *m_field_metadata;
   uchar *m_null_bits;
   uchar *m_memory;
 };

storage/federated/ha_federated.cc

@@ -3169,7 +3169,7 @@ int ha_federated::external_lock(THD *thd, int lock_type)
 #ifdef XXX_SUPERCEDED_BY_WL2952
   if (lock_type != F_UNLCK)
   {
-    ha_federated *trx= (ha_federated *)thd->ha_data[ht->slot];
+    ha_federated *trx= (ha_federated *)thd_get_ha_data(thd, ht);
 
     DBUG_PRINT("info",("federated not lock F_UNLCK"));
     if (!(thd->options & (OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN))) 
@@ -3200,7 +3200,7 @@ int ha_federated::external_lock(THD *thd, int lock_type)
           DBUG_PRINT("info", ("error setting autocommit FALSE: %d", error));
           DBUG_RETURN(error);
         }
-        thd->ha_data[ht->slot]= this;
+        thd_set_ha_data(thd, ht, this);
         trans_register_ha(thd, TRUE, ht);
         /*
           Send a lock table to the remote end.
@@ -3230,7 +3230,7 @@ int ha_federated::external_lock(THD *thd, int lock_type)
 static int federated_commit(handlerton *hton, THD *thd, bool all)
 {
   int return_val= 0;
-  ha_federated *trx= (ha_federated *)thd->ha_data[hton->slot];
+  ha_federated *trx= (ha_federated *) thd_get_ha_data(thd, hton);
   DBUG_ENTER("federated_commit");
 
   if (all)
@@ -3245,7 +3245,7 @@ static int federated_commit(handlerton *hton, THD *thd, bool all)
       if (error && !return_val)
         return_val= error;
     }
-    thd->ha_data[hton->slot]= NULL;
+    thd_set_ha_data(thd, hton, NULL);
   }
 
   DBUG_PRINT("info", ("error val: %d", return_val));
@@ -3256,7 +3256,7 @@ static int federated_commit(handlerton *hton, THD *thd, bool all)
 static int federated_rollback(handlerton *hton, THD *thd, bool all)
 {
   int return_val= 0;
-  ha_federated *trx= (ha_federated *)thd->ha_data[hton->slot];
+  ha_federated *trx= (ha_federated *)thd_get_ha_data(thd, hton);
   DBUG_ENTER("federated_rollback");
 
   if (all)
@@ -3271,7 +3271,7 @@ static int federated_rollback(handlerton *hton, THD *thd, bool all)
       if (error && !return_val)
         return_val= error;
     }
-    thd->ha_data[hton->slot]= NULL;
+    thd_set_ha_data(thd, hton, NULL);
   }
 
   DBUG_PRINT("info", ("error val: %d", return_val));