Bug#13548704 ALGORITHM USED FOR DROPPING PARTITIONED TABLE CAN LEAD

             TO INCONSISTENCY 
[Merge from 5.1]

mysql-test/r/partition_myisam.result

@@ -106,8 +106,8 @@ test.t1	check	Error	Incorrect information in file: './test/t1.frm'
 test.t1	check	error	Corrupt
 SELECT * FROM t1;
 ERROR HY000: Failed to read from the .par file
-# Note that it is currently impossible to drop a partitioned table
-# without the .par file
+# Note that we will remove the frm file when we detect that
+# .par file has been deleted.
 DROP TABLE t1;
 ERROR 42S02: Unknown table 't1'
 #

mysql-test/t/partition_myisam.test

@@ -86,11 +86,10 @@ FLUSH TABLES;
 CHECK TABLE t1;
 --error ER_FAILED_READ_FROM_PAR_FILE
 SELECT * FROM t1;
---echo # Note that it is currently impossible to drop a partitioned table
---echo # without the .par file
+--echo # Note that we will remove the frm file when we detect that
+--echo # .par file has been deleted.
 --error ER_BAD_TABLE_ERROR
 DROP TABLE t1;
---remove_file $MYSQLD_DATADIR/test/t1.frm
 --remove_file $MYSQLD_DATADIR/test/t1#P#p0.MYI
 --remove_file $MYSQLD_DATADIR/test/t1#P#p0.MYD
 

sql/ha_partition.cc

@@ -1930,15 +1930,15 @@ char *ha_partition::update_table_comment(const char *comment)
     names of the partitions and the underlying storage engines.
 */
 
-uint ha_partition::del_ren_cre_table(const char *from,
+int ha_partition::del_ren_cre_table(const char *from,
 				     const char *to,
 				     TABLE *table_arg,
 				     HA_CREATE_INFO *create_info)
 {
   int save_error= 0;
-  int error;
+  int error= HA_ERR_INTERNAL_ERROR;
   char from_buff[FN_REFLEN], to_buff[FN_REFLEN], from_lc_buff[FN_REFLEN],
-       to_lc_buff[FN_REFLEN];
+       to_lc_buff[FN_REFLEN], buff[FN_REFLEN];
   char *name_buffer_ptr;
   const char *from_path;
   const char *to_path= NULL;
@@ -1950,24 +1950,28 @@ uint ha_partition::del_ren_cre_table(const char *from,
   if (create_info && create_info->options & HA_LEX_CREATE_TMP_TABLE)
   {
     my_error(ER_PARTITION_NO_TEMPORARY, MYF(0));
-    DBUG_RETURN(TRUE);
+    DBUG_RETURN(error);
+  }
+
+  fn_format(buff,from, "", ha_par_ext, MY_APPEND_EXT);
+  /* Check if the  par file exists */
+  if (my_access(buff,F_OK))
+  {
+    /*
+      If the .par file does not exist, return HA_ERR_NO_SUCH_TABLE,
+      This will signal to the caller that it can remove the .frm
+      file.
+    */
+    error= HA_ERR_NO_SUCH_TABLE;
+    DBUG_RETURN(error);
   }
 
   if (get_from_handler_file(from, ha_thd()->mem_root, false))
-    DBUG_RETURN(TRUE);
+    DBUG_RETURN(error);
   DBUG_ASSERT(m_file_buffer);
   DBUG_PRINT("enter", ("from: (%s) to: (%s)", from, to ? to : "(nil)"));
   name_buffer_ptr= m_name_buffer_ptr;
   file= m_file;
-  if (to == NULL && table_arg == NULL)
-  {
-    /*
-      Delete table, start by delete the .par file. If error, break, otherwise
-      delete as much as possible.
-    */
-    if ((error= handler::delete_table(from)))
-      DBUG_RETURN(error);
-  }
   /*
     Since ha_partition has HA_FILE_BASED, it must alter underlying table names
     if they do not have HA_FILE_BASED and lower_case_table_names == 2.
@@ -2006,6 +2010,18 @@ uint ha_partition::del_ren_cre_table(const char *from,
       save_error= error;
     i++;
   } while (*(++file));
+
+  if (to == NULL && table_arg == NULL)
+  {
+    DBUG_EXECUTE_IF("crash_before_deleting_par_file", DBUG_SUICIDE(););
+
+    /* Delete the .par file. If error, break.*/
+    if ((error= handler::delete_table(from)))
+      DBUG_RETURN(error);
+
+    DBUG_EXECUTE_IF("crash_after_deleting_par_file", DBUG_SUICIDE(););
+  }
+
   if (to != NULL)
   {
     if ((error= handler::rename_table(from, to)))

sql/ha_partition.h

@@ -275,7 +275,7 @@ private:
     delete_table, rename_table and create uses very similar logic which
     is packed into this routine.
   */
-  uint del_ren_cre_table(const char *from, const char *to,
+  int del_ren_cre_table(const char *from, const char *to,
                          TABLE *table_arg, HA_CREATE_INFO *create_info);
   /*
     One method to create the table_name.par file containing the names of the