Bug #17720 Partition ALTER TABLE fails on rename of .MYI file

Fix this by passing the HA_EXTRA_PREPARE_FOR_DELETE onto the newly added or about to be dropped partitions
so they have an opportunity to close their OS file handle.


client/mysqltest.c:
  prevent positive find of pattern when pattern has zero length (this has nothing to do with this bug fix)
sql/ha_partition.cc:
  initialize m_new_file to NULL
  call new function prepare_for_delete for the HA_EXTRA_PREPARE_FOR_DELETE operation
  inside prepare_for_delete, loop over m_new_file and m_reorged_file if they are non-NULL
sql/ha_partition.h:
  added decl for new prepare_for_delete function

client/mysqltest.c

@@ -3736,6 +3736,7 @@ static void fix_win_paths(const char* val, int len)
   {
     const char** pattern= dynamic_element(&patterns, i, const char**);
     DBUG_PRINT("info", ("pattern: %s", *pattern));
+    if (strlen(*pattern) == 0) continue;
     /* Search for the path in string */
     while ((p= strstr(val, *pattern)))
     {

sql/ha_partition.cc

@@ -218,6 +218,7 @@ void ha_partition::init_handler_variables()
   m_engine_array= NULL;
   m_file= NULL;
   m_reorged_file= NULL;
+  m_new_file= NULL;
   m_reorged_parts= 0;
   m_added_file= NULL;
   m_tot_parts= 0;
@@ -4680,11 +4681,13 @@ int ha_partition::extra(enum ha_extra_function operation)
   }
 
   /* Category 3), used by MyISAM handlers */
+  case HA_EXTRA_PREPARE_FOR_DELETE:
+    DBUG_RETURN(prepare_for_delete());
+    break;
   case HA_EXTRA_NORMAL:
   case HA_EXTRA_QUICK:
   case HA_EXTRA_NO_READCHECK:
   case HA_EXTRA_PREPARE_FOR_UPDATE:
-  case HA_EXTRA_PREPARE_FOR_DELETE:
   case HA_EXTRA_FORCE_REOPEN:
   case HA_EXTRA_FLUSH_CACHE:
   {
@@ -4793,6 +4796,41 @@ void ha_partition::prepare_extra_cache(uint cachesize)
 }
 
 
+/*
+  Prepares our new and reorged handlers for rename or delete
+
+  SYNOPSIS
+    prepare_for_delete()
+
+  RETURN VALUE
+    >0                    Error code
+    0                     Success
+*/
+
+int ha_partition::prepare_for_delete()
+{
+  int result= 0, tmp;
+  handler **file;
+  DBUG_ENTER("ha_partition::prepare_for_delete()");
+  
+  if (m_new_file != NULL)
+  {
+    for (file= m_new_file; *file; file++)
+      if ((tmp= (*file)->extra(HA_EXTRA_PREPARE_FOR_DELETE)))
+        result= tmp;      
+    for (file= m_reorged_file; *file; file++)
+      if ((tmp= (*file)->extra(HA_EXTRA_PREPARE_FOR_DELETE)))
+        result= tmp;      
+  }
+  else
+  {
+    for (file= m_file; *file; file++)
+      if ((tmp= (*file)->extra(HA_EXTRA_PREPARE_FOR_DELETE)))
+        result= tmp;      
+  }
+  DBUG_RETURN(result);
+}
+
 /*
   Call extra on all partitions
 
@@ -4810,6 +4848,7 @@ int ha_partition::loop_extra(enum ha_extra_function operation)
   int result= 0, tmp;
   handler **file;
   DBUG_ENTER("ha_partition::loop_extra()");
+  
   /* 
     TODO, 5.2: this is where you could possibly add optimisations to add the bitmap
     _if_ a SELECT.

sql/ha_partition.h

@@ -197,6 +197,7 @@ class ha_partition :public handler
     DBUG_RETURN(0);
   }
 private:
+  int prepare_for_delete();
   int copy_partitions(ulonglong *copied, ulonglong *deleted);
   void cleanup_new_partition(uint part_count);
   int prepare_new_partition(TABLE *table, HA_CREATE_INFO *create_info,