MDEV-21983: Crash on DROP/RENAME TABLE after DISCARD TABLESPACE

fil_delete_tablespace(): Remove the unused parameter drop_ahi,
and add the parameter if_exists=false. We want to suppress
error messages if we know that the tablespace has been discarded.

dict_table_rename_in_cache(): Pass the new parameter to
fil_delete_tablespace(), that is, do not complain about
missing tablespace if the tablespace has been discarded.

row_make_new_pathname(): Declare as static.

row_drop_table_for_mysql(): Tolerate !table->data_dir_path
when the tablespace has been discarded.

row_rename_table_for_mysql(): Skip part of the RENAME TABLE
when fil_space_get_first_path() returns NULL.

mysql-test/suite/innodb/r/alter_missing_tablespace.result

@@ -35,7 +35,9 @@ ALTER TABLE t DISCARD TABLESPACE;
 Warnings:
 Warning	1812	Tablespace is missing for table 'test/t'
 Warning	1812	Tablespace is missing for table 'test/t'
-DROP TABLE t;
+RENAME TABLE t TO u;
+RENAME TABLE u TO v;
+DROP TABLE v;
 SELECT * FROM `x..d`;
 ERROR HY000: Got error 194 "Tablespace is missing for a table" from storage engine InnoDB
 DROP TABLE `x..d`;

mysql-test/suite/innodb/t/alter_missing_tablespace.test

@@ -58,7 +58,9 @@ ALTER TABLE t ALGORITHM=COPY, DISCARD TABLESPACE;
 --error ER_PARSE_ERROR
 ALTER TABLE t ALGORITHM=DEFAULT, DISCARD TABLESPACE;
 ALTER TABLE t DISCARD TABLESPACE;
-DROP TABLE t;
+RENAME TABLE t TO u;
+RENAME TABLE u TO v;
+DROP TABLE v;
 --error ER_GET_ERRNO
 SELECT * FROM `x..d`;
 DROP TABLE `x..d`;

storage/innobase/dict/dict0dict.cc

@@ -1630,7 +1630,8 @@ dict_table_rename_in_cache(
 			return(DB_OUT_OF_MEMORY);
 		}
 
-		fil_delete_tablespace(table->space);
+		fil_delete_tablespace(table->space,
+				      dict_table_is_discarded(table));
 
 		/* Delete any temp file hanging around. */
 		if (os_file_status(filepath, &exists, &ftype)

storage/innobase/fil/fil0fil.cc

@@ -2861,14 +2861,9 @@ bool fil_table_accessible(const dict_table_t* table)
 
 /** Delete a tablespace and associated .ibd file.
 @param[in]	id		tablespace identifier
+@param[in]	if_exists	whether to ignore missing tablespace
 @return	DB_SUCCESS or error */
-dberr_t
-fil_delete_tablespace(
-	ulint id
-#ifdef BTR_CUR_HASH_ADAPT
-	, bool drop_ahi /*!< whether to drop the adaptive hash index */
-#endif /* BTR_CUR_HASH_ADAPT */
-	)
+dberr_t fil_delete_tablespace(ulint id, bool if_exists)
 {
 	char*		path = 0;
 	fil_space_t*	space = 0;
@@ -2879,10 +2874,11 @@ fil_delete_tablespace(
 		id, FIL_OPERATION_DELETE, &space, &path);
 
 	if (err != DB_SUCCESS) {
-
-		ib::error() << "Cannot delete tablespace " << id
-			<< " because it is not found in the tablespace"
-			" memory cache.";
+		if (!if_exists) {
+			ib::error() << "Cannot delete tablespace " << id
+				    << " because it is not found"
+				       " in the tablespace memory cache.";
+		}
 
 		return(err);
 	}

storage/innobase/include/fil0fil.h

 /*****************************************************************************
 
 Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2013, 2019, MariaDB Corporation.
+Copyright (c) 2013, 2020, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -964,14 +964,9 @@ bool fil_table_accessible(const dict_table_t* table)
 
 /** Delete a tablespace and associated .ibd file.
 @param[in]	id		tablespace identifier
+@param[in]	if_exists	whether to ignore missing tablespace
 @return	DB_SUCCESS or error */
-dberr_t
-fil_delete_tablespace(
-	ulint id
-#ifdef BTR_CUR_HASH_ADAPT
-	, bool drop_ahi = false /*!< whether to drop the adaptive hash index */
-#endif /* BTR_CUR_HASH_ADAPT */
-	);
+dberr_t fil_delete_tablespace(ulint id, bool if_exists= false);
 
 /** Prepare to truncate an undo tablespace.
 @param[in]	space_id	undo tablespace id

storage/innobase/include/row0merge.h

 /*****************************************************************************
 
 Copyright (c) 2005, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2019, MariaDB Corporation.
+Copyright (c) 2015, 2020, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -202,18 +202,6 @@ row_merge_file_destroy_low(
 /*=======================*/
 	int		fd);	/*!< in: merge file descriptor */
 
-/*********************************************************************//**
-Provide a new pathname for a table that is being renamed if it belongs to
-a file-per-table tablespace.  The caller is responsible for freeing the
-memory allocated for the return value.
-@return new pathname of tablespace file, or NULL if space = 0 */
-char*
-row_make_new_pathname(
-/*==================*/
-	dict_table_t*	table,		/*!< in: table to be renamed */
-	const char*	new_name)	/*!< in: new name */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-
 /*********************************************************************//**
 Rename the tables in the data dictionary.  The data dictionary must
 have been locked exclusively by the caller, because the transaction

storage/innobase/row/row0merge.cc

@@ -4149,6 +4149,7 @@ Provide a new pathname for a table that is being renamed if it belongs to
 a file-per-table tablespace.  The caller is responsible for freeing the
 memory allocated for the return value.
 @return new pathname of tablespace file, or NULL if space = 0 */
+static
 char*
 row_make_new_pathname(
 /*==================*/

storage/innobase/row/row0mysql.cc

@@ -3725,10 +3725,12 @@ row_drop_table_for_mysql(
 		dict_table_t.  Free this memory before returning. */
 		if (DICT_TF_HAS_DATA_DIR(table->flags)) {
 			dict_get_and_save_data_dir_path(table, true);
-			ut_a(table->data_dir_path);
+			ut_ad(table->data_dir_path
+			      || dict_table_is_discarded(table));
 			filepath = fil_make_filepath(
 				table->data_dir_path,
-				table->name.m_name, IBD, true);
+				table->name.m_name, IBD,
+				table->data_dir_path != NULL);
 		} else {
 			filepath = fil_make_filepath(
 				NULL, table->name.m_name, IBD, false);
@@ -4304,11 +4306,9 @@ row_rename_table_for_mysql(
 
 	/* SYS_TABLESPACES and SYS_DATAFILES need to be updated if
 	the table is in a single-table tablespace. */
-	if (err == DB_SUCCESS
-	    && dict_table_is_file_per_table(table)) {
-		/* Make a new pathname to update SYS_DATAFILES. */
-		char*	new_path = row_make_new_pathname(table, new_name);
-		char*	old_path = fil_space_get_first_path(table->space);
+	if (err != DB_SUCCESS || !dict_table_is_file_per_table(table)) {
+	} else if (char* old_path = fil_space_get_first_path(table->space)) {
+		char* new_path = os_file_make_new_pathname(old_path, new_name);
 
 		/* If old path and new path are the same means tablename
 		has not changed and only the database name holding the table