Manual merge from mysql-trunk-merge.

Conflicts:
  - client/mysql.cc
  - client/mysqldump.c
  - configure.in
  - mysql-test/r/csv.result
  - mysql-test/r/func_time.result
  - mysql-test/r/show_check.result
  - mysql-test/r/sp-error.result
  - mysql-test/r/sp.result
  - mysql-test/r/sp_trans.result
  - mysql-test/r/type_blob.result
  - mysql-test/r/type_timestamp.result
  - mysql-test/r/warnings.result
  - mysql-test/suite/rpl/r/rpl_sp.result
  - sql/mysql_priv.h
  - sql/mysqld.cc
  - sql/sp.cc
  - sql/sql_base.cc
  - sql/sql_table.cc
  - sql/sql_trigger.cc
  - sql/sql_view.cc
  - sql/table.h
  - sql/share/errmsg.txt
  - mysql-test/suite/sys_vars/r/log_bin_trust_routine_creators_basic.result

1 files changed, 27 insertions, 6 deletions

diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc
index 3289b529edf..877cf070abd 100644
--- a/sql/ha_partition.cc
+++ b/sql/ha_partition.cc
@@ -1803,13 +1803,23 @@ void ha_partition::update_create_info(HA_CREATE_INFO *create_info)
 
 void ha_partition::change_table_ptr(TABLE *table_arg, TABLE_SHARE *share)
 {
-  handler **file_array= m_file;
+  handler **file_array;
   table= table_arg;
   table_share= share;
-  do
+  /*
+    m_file can be NULL when using an old cached table in DROP TABLE, when the
+    table just has REMOVED PARTITIONING, see Bug#42438
+  */
+  if (m_file)
   {
-    (*file_array)->change_table_ptr(table_arg, share);
-  } while (*(++file_array));
+    file_array= m_file;
+    DBUG_ASSERT(*file_array);
+    do
+    {
+      (*file_array)->change_table_ptr(table_arg, share);
+    } while (*(++file_array));
+  }
+
   if (m_added_file && m_added_file[0])
   {
     /* if in middle of a drop/rename etc */
@@ -6226,7 +6236,13 @@ void ha_partition::print_error(int error, myf errflag)
       thd->lex->sql_command != SQLCOM_TRUNCATE)
     m_part_info->print_no_partition_found(table);
   else
-    m_file[m_last_part]->print_error(error, errflag);
+  {
+    /* In case m_file has not been initialized, like in bug#42438 */
+    if (m_file)
+      m_file[m_last_part]->print_error(error, errflag);
+    else
+      handler::print_error(error, errflag);
+  }
   DBUG_VOID_RETURN;
 }
 
@@ -6236,7 +6252,12 @@ bool ha_partition::get_error_message(int error, String *buf)
   DBUG_ENTER("ha_partition::get_error_message");
 
   /* Should probably look for my own errors first */
-  DBUG_RETURN(m_file[m_last_part]->get_error_message(error, buf));
+
+  /* In case m_file has not been initialized, like in bug#42438 */
+  if (m_file)
+    DBUG_RETURN(m_file[m_last_part]->get_error_message(error, buf));
+  DBUG_RETURN(handler::get_error_message(error, buf));
+
 }