MDEV-26148 SEGV or Assertion `!page_is_comp(page) == !(index->table)-…

…>not_redundant()'

FetchIndexRootPages::operator(): handle REDUNDANT vs DYNAMIC case specifically.
Other combinations seems fine as is.

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

@@ -0,0 +1,12 @@
+call mtr.add_suppression("Index for table 'imp_t1' is corrupt; try to repair it");
+SET @save_innodb_checksum_algorithm=@@GLOBAL.innodb_checksum_algorithm;
+SET GLOBAL innodb_checksum_algorithm=full_crc32;
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
+CREATE TABLE imp_t1 (a INT PRIMARY KEY) ENGINE=InnoDB ROW_FORMAT=DYNAMIC;
+ALTER TABLE imp_t1 DISCARD TABLESPACE ;
+FLUSH TABLES t1 FOR EXPORT;
+UNLOCK TABLES;
+ALTER TABLE imp_t1 IMPORT TABLESPACE;
+ERROR HY000: Schema mismatch (ROW_FORMAT mismatch)
+DROP TABLE imp_t1, t1;
+SET GLOBAL innodb_checksum_algorithm=@save_innodb_checksum_algorithm;

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

@@ -0,0 +1,19 @@
+--source include/have_innodb.inc
+
+call mtr.add_suppression("Index for table 'imp_t1' is corrupt; try to repair it");
+
+SET @save_innodb_checksum_algorithm=@@GLOBAL.innodb_checksum_algorithm;
+SET GLOBAL innodb_checksum_algorithm=full_crc32;
+
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
+CREATE TABLE imp_t1 (a INT PRIMARY KEY) ENGINE=InnoDB ROW_FORMAT=DYNAMIC;
+ALTER TABLE imp_t1 DISCARD TABLESPACE ;
+FLUSH TABLES t1 FOR EXPORT;
+let $datadir=`select @@datadir`;
+--copy_file $datadir/test/t1.ibd $datadir/test/imp_t1.ibd
+UNLOCK TABLES;
+--error ER_TABLE_SCHEMA_MISMATCH
+ALTER TABLE imp_t1 IMPORT TABLESPACE;
+DROP TABLE imp_t1, t1;
+
+SET GLOBAL innodb_checksum_algorithm=@save_innodb_checksum_algorithm;

storage/innobase/row/row0import.cc

@@ -680,6 +680,14 @@ dberr_t FetchIndexRootPages::operator()(buf_block_t* block) UNIV_NOTHROW
 				return(DB_CORRUPTION);
 			}
 		}
+
+		if (!page_is_comp(block->frame) !=
+		    !dict_table_is_comp(m_table)) {
+			ib_errf(m_trx->mysql_thd, IB_LOG_LEVEL_ERROR,
+				ER_TABLE_SCHEMA_MISMATCH,
+				"ROW_FORMAT mismatch");
+			return DB_CORRUPTION;
+		}
 	}
 
 	return DB_SUCCESS;