MDEV-17070 Table corruption or Assertion `table->file->stats.records > 0 || error' or Assertion `!is_set() || (m_status == DA_OK_BULK && is_bulk_op())' failed upon actions on temporary table

This was caused by a combination of factors:
* MyISAM/Aria temporary tables historically never saved the state
  to disk (MYI/MAI), because the state never needed to persist
* certain ALTER TABLE operations modify the original TABLE structure
  and if they fail, the original table has to be reopened to
  revert all changes (m_needs_reopen=1)

as a result, when ALTER fails and MyISAM/Aria temp table gets reopened,
it reads the stale state from the disk.

As a fix, MyISAM/Aria tables now *always* write the state to disk
on close, *unless* HA_EXTRA_PREPARE_FOR_DROP was done first. And
the server now always does HA_EXTRA_PREPARE_FOR_DROP before dropping
a temporary table.

4 files changed, 7 insertions, 18 deletions

diff --git a/storage/maria/ma_blockrec.c b/storage/maria/ma_blockrec.c
index 0b55a03f902..4395613862e 100644
--- a/storage/maria/ma_blockrec.c
+++ b/storage/maria/ma_blockrec.c
@@ -449,9 +449,7 @@ my_bool _ma_once_end_block_record(MARIA_SHARE *share)
   if (share->bitmap.file.file >= 0)
   {
     if (flush_pagecache_blocks(share->pagecache, &share->bitmap.file,
-                               ((share->temporary || share->deleting) ?
-                                FLUSH_IGNORE_CHANGED :
-                                FLUSH_RELEASE)))
+                       share->deleting ? FLUSH_IGNORE_CHANGED : FLUSH_RELEASE))
       res= 1;
     /*
       File must be synced as it is going out of the maria_open_list and so
diff --git a/storage/maria/ma_close.c b/storage/maria/ma_close.c
index 6e85551c24f..08bb7cee138 100644
--- a/storage/maria/ma_close.c
+++ b/storage/maria/ma_close.c
@@ -47,9 +47,7 @@ int maria_close(register MARIA_HA *info)
       a global mutex
     */
     if (flush_pagecache_blocks(share->pagecache, &share->kfile,
-                               ((share->temporary || share->deleting) ?
-                                FLUSH_IGNORE_CHANGED :
-                                FLUSH_RELEASE)))
+                       share->deleting ? FLUSH_IGNORE_CHANGED : FLUSH_RELEASE))
       error= my_errno;
   }
 
@@ -113,23 +111,14 @@ int maria_close(register MARIA_HA *info)
         since the start of the function (very unlikely)
       */
       if (flush_pagecache_blocks(share->pagecache, &share->kfile,
-                                 ((share->temporary || share->deleting) ?
-                                  FLUSH_IGNORE_CHANGED :
-                                  FLUSH_RELEASE)))
+                        share->deleting ? FLUSH_IGNORE_CHANGED : FLUSH_RELEASE))
         error= my_errno;
 #ifdef HAVE_MMAP
       if (share->file_map)
         _ma_unmap_file(info);
 #endif
-      /*
-        If we are crashed, we can safely flush the current state as it will
-        not change the crashed state.
-        We can NOT write the state in other cases as other threads
-        may be using the file at this point
-        IF using --external-locking, which does not apply to Maria.
-      */
       if (((share->changed && share->base.born_transactional) ||
-           maria_is_crashed(info)))
+           maria_is_crashed(info) || (share->temporary && !share->deleting)))
       {
         if (save_global_changed)
         {
diff --git a/storage/maria/ma_extra.c b/storage/maria/ma_extra.c
index 9feead42cf7..47c796daab3 100644
--- a/storage/maria/ma_extra.c
+++ b/storage/maria/ma_extra.c
@@ -314,6 +314,8 @@ int maria_extra(MARIA_HA *info, enum ha_extra_function function,
     share->state.open_count= 1;
     share->changed= 1;
     _ma_mark_file_changed_now(share);
+    if (share->temporary)
+      break;
     /* fall through */
   case HA_EXTRA_PREPARE_FOR_RENAME:
   {
diff --git a/storage/maria/ma_open.c b/storage/maria/ma_open.c
index a781b7e00d3..6d507cee7d8 100644
--- a/storage/maria/ma_open.c
+++ b/storage/maria/ma_open.c
@@ -1374,7 +1374,7 @@ uint _ma_state_info_write(MARIA_SHARE *share, uint pWrite)
 
   if (pWrite & MA_STATE_INFO_WRITE_LOCK)
     mysql_mutex_lock(&share->intern_lock);
-  else if (maria_multi_threaded)
+  else if (maria_multi_threaded && !share->temporary)
     mysql_mutex_assert_owner(&share->intern_lock);
   if (share->base.born_transactional && translog_status == TRANSLOG_OK &&
       !maria_in_recovery)