MDEV-19055 Failures with temporary tables and Aria

There was two separate problems:
- Aria pagecache didn't properly handle re-reading of blocks
  that have given errors before (this triggered an assert)
- temporary tables that where opened several times where
  not properly closed in ALTER, REPAIR or OPTIMIZE table

Other things
- Added a couple of asserts that will make it easier to
  find problems like this in the future.

2 files changed, 3 insertions, 2 deletions

diff --git a/storage/maria/ma_blockrec.c b/storage/maria/ma_blockrec.c
index c38b27d0f6c..13323dcae55 100644
--- a/storage/maria/ma_blockrec.c
+++ b/storage/maria/ma_blockrec.c
@@ -5244,6 +5244,8 @@ my_bool _ma_scan_init_block_record(MARIA_HA *info)
 {
   MARIA_SHARE *share= info->s;
   DBUG_ENTER("_ma_scan_init_block_record");
+  DBUG_ASSERT(info->dfile.file == share->bitmap.file.file);
+
   /*
     bitmap_buff may already be allocated if this is the second call to
     rnd_init() without a rnd_end() in between, see sql/handler.h
diff --git a/storage/maria/ma_pagecache.c b/storage/maria/ma_pagecache.c
index 7b0f395f926..f8c83e12a18 100644
--- a/storage/maria/ma_pagecache.c
+++ b/storage/maria/ma_pagecache.c
@@ -3464,8 +3464,6 @@ restart:
         pagecache_pthread_mutex_lock(&pagecache->cache_lock);
 #endif
       }
-      if (status & PCBLOCK_ERROR)
-        my_errno= block->error;
     }
 
     remove_reader(block);
@@ -3497,6 +3495,7 @@ restart:
 
     if (status & PCBLOCK_ERROR)
     {
+      my_errno= block->error;
       DBUG_ASSERT(my_errno != 0);
       DBUG_PRINT("error", ("Got error %d when doing page read", my_errno));
       DBUG_RETURN((uchar *) 0);