MDEV-27973 SIGSEGV in ha_innobase::reset() after TRUNCATE of TEMPORARY TABLE

create_table_info_t::innobase_table_flags(): Ignore page_compressed
and page_compression_level on TEMPORARY tables.

ha_innobase::truncate(): Add a debug assertion that create() must succeed
on temporary tables.

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

@@ -58,10 +58,13 @@ CREATE TABLE t(c INT) ENGINE=InnoDB page_compressed=1;
 DROP TABLE IF EXISTS t;
 SET GLOBAL innodb_compression_level=1;
 CREATE TABLE t(a INT)ENGINE=InnoDB ROW_FORMAT=DYNAMIC page_compressed=1;
+CREATE TEMPORARY TABLE tt(a INT PRIMARY KEY)
+ROW_FORMAT=DYNAMIC page_compressed=1 ENGINE=InnoDB;
 SET GLOBAL innodb_compression_level=0;
 ALTER TABLE t FORCE, ROW_FORMAT=DEFAULT, ALGORITHM=INPLACE;
 ERROR HY000: Table storage engine 'InnoDB' does not support the create option 'PAGE_COMPRESSED'
 ALTER TABLE t FORCE, ROW_FORMAT=DEFAULT, ALGORITHM=COPY;
 ERROR HY000: Can't create table `test`.`t` (errno: 140 "Wrong create options")
 DROP TABLE t;
+TRUNCATE tt;
 SET GLOBAL innodb_compression_level=@save_level;

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

@@ -69,10 +69,13 @@ DROP TABLE IF EXISTS t;
 
 SET GLOBAL innodb_compression_level=1;
 CREATE TABLE t(a INT)ENGINE=InnoDB ROW_FORMAT=DYNAMIC page_compressed=1;
+CREATE TEMPORARY TABLE tt(a INT PRIMARY KEY)
+ROW_FORMAT=DYNAMIC page_compressed=1 ENGINE=InnoDB;
 SET GLOBAL innodb_compression_level=0;
 --error ER_ILLEGAL_HA_CREATE_OPTION
 ALTER TABLE t FORCE, ROW_FORMAT=DEFAULT, ALGORITHM=INPLACE;
 --error ER_CANT_CREATE_TABLE
 ALTER TABLE t FORCE, ROW_FORMAT=DEFAULT, ALGORITHM=COPY;
 DROP TABLE t;
+TRUNCATE tt;
 SET GLOBAL innodb_compression_level=@save_level;

storage/innobase/handler/ha_innodb.cc

@@ -11776,29 +11776,33 @@ bool create_table_info_t::innobase_table_flags()
 		zip_ssize = 0;
 	}
 
+	ulint level = 0;
+
 	if (is_temp) {
 		m_flags2 |= DICT_TF2_TEMPORARY;
-	} else if (m_use_file_per_table) {
-		m_flags2 |= DICT_TF2_USE_FILE_PER_TABLE;
-	}
+	} else {
+		if (m_use_file_per_table) {
+			m_flags2 |= DICT_TF2_USE_FILE_PER_TABLE;
+		}
 
-	ulint level = ulint(options->page_compression_level);
-	if (!level) {
-		level = page_zip_level;
-		if (!level && options->page_compressed) {
-			push_warning_printf(
-				m_thd, Sql_condition::WARN_LEVEL_WARN,
-				ER_ILLEGAL_HA_CREATE_OPTION,
-				"InnoDB: PAGE_COMPRESSED requires"
-				" PAGE_COMPRESSION_LEVEL or"
-				" innodb_compression_level > 0");
-			DBUG_RETURN(false);
+		level = ulint(options->page_compression_level);
+		if (!level) {
+			level = page_zip_level;
+			if (!level && options->page_compressed) {
+				push_warning_printf(
+					m_thd, Sql_condition::WARN_LEVEL_WARN,
+					ER_ILLEGAL_HA_CREATE_OPTION,
+					"InnoDB: PAGE_COMPRESSED requires"
+					" PAGE_COMPRESSION_LEVEL or"
+					" innodb_compression_level > 0");
+				DBUG_RETURN(false);
+			}
 		}
 	}
 
 	/* Set the table flags */
 	dict_tf_set(&m_flags, innodb_row_format, zip_ssize,
-		    m_use_data_dir, options->page_compressed, level);
+		    m_use_data_dir, level && options->page_compressed, level);
 
 	if (m_form->s->table_type == TABLE_TYPE_SEQUENCE) {
 		m_flags |= DICT_TF_MASK_NO_ROLLBACK;
@@ -13856,6 +13860,7 @@ int ha_innobase::truncate()
 
 		int err = create(ib_table->name.m_name, table, &info, true,
 				 trx);
+		ut_ad(!err);
 		if (!err) {
 			err = open(ib_table->name.m_name, 0, 0);
 			m_prebuilt->stored_select_lock_type = stored_lock;