MDEV-17483 Insert on delete-marked record can wrongly inherit old values for instantly added column

row_ins_clust_index_entry_low(): Do not call dtuple_t::trim()
before row_ins_clust_index_entry_by_modify(), so that the values
of all columns will be available in row_upd_build_difference_binary().
If applicable, the tuple can be trimmed in btr_cur_optimistic_update()
or btr_cur_pessimistic_update(), which will be called by
row_ins_clust_index_entry_by_modify().

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

@@ -471,6 +471,21 @@ Table	Op	Msg_type	Msg_text
 test.t2	check	status	OK
 test.t1	check	status	OK
 DROP TABLE t2, t1;
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
+INSERT INTO t1 SET a = 1;
+ALTER TABLE t1 ADD COLUMN b TEXT;
+BEGIN;
+UPDATE t1 SET b = REPEAT('1', 32768);
+UPDATE t1 SET a = 2;
+INSERT INTO t1 SET a = 1;
+SELECT a,LENGTH(b) FROM t1;
+a	LENGTH(b)
+1	NULL
+2	32768
+DELETE FROM t1;
+COMMIT;
+InnoDB		0 transactions not purged
+DROP TABLE t1;
 CREATE TABLE t1
 (id INT PRIMARY KEY, c2 INT UNIQUE,
 c3 POINT NOT NULL DEFAULT ST_GeomFromText('POINT(3 4)'),
@@ -888,6 +903,21 @@ Table	Op	Msg_type	Msg_text
 test.t2	check	status	OK
 test.t1	check	status	OK
 DROP TABLE t2, t1;
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB ROW_FORMAT=COMPACT;
+INSERT INTO t1 SET a = 1;
+ALTER TABLE t1 ADD COLUMN b TEXT;
+BEGIN;
+UPDATE t1 SET b = REPEAT('1', 32768);
+UPDATE t1 SET a = 2;
+INSERT INTO t1 SET a = 1;
+SELECT a,LENGTH(b) FROM t1;
+a	LENGTH(b)
+1	NULL
+2	32768
+DELETE FROM t1;
+COMMIT;
+InnoDB		0 transactions not purged
+DROP TABLE t1;
 CREATE TABLE t1
 (id INT PRIMARY KEY, c2 INT UNIQUE,
 c3 POINT NOT NULL DEFAULT ST_GeomFromText('POINT(3 4)'),
@@ -1305,10 +1335,25 @@ Table	Op	Msg_type	Msg_text
 test.t2	check	status	OK
 test.t1	check	status	OK
 DROP TABLE t2, t1;
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB ROW_FORMAT=DYNAMIC;
+INSERT INTO t1 SET a = 1;
+ALTER TABLE t1 ADD COLUMN b TEXT;
+BEGIN;
+UPDATE t1 SET b = REPEAT('1', 32768);
+UPDATE t1 SET a = 2;
+INSERT INTO t1 SET a = 1;
+SELECT a,LENGTH(b) FROM t1;
+a	LENGTH(b)
+1	NULL
+2	32768
+DELETE FROM t1;
+COMMIT;
+InnoDB		0 transactions not purged
+DROP TABLE t1;
 disconnect analyze;
 SELECT variable_value-@old_instant instants
 FROM information_schema.global_status
 WHERE variable_name = 'innodb_instant_alter_column';
 instants
-48
+51
 SET GLOBAL innodb_purge_rseg_truncate_frequency= @saved_frequency;

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

@@ -343,6 +343,24 @@ DEFAULT REPEAT('a', @@GLOBAL.innodb_page_size * .75);
 CHECK TABLE t2, t1;
 DROP TABLE t2, t1;
 
+#
+# MDEV-17483 Insert on delete-marked record can wrongly inherit old values
+# for instantly added column
+#
+
+eval CREATE TABLE t1 (a INT PRIMARY KEY) $engine;
+INSERT INTO t1 SET a = 1;
+ALTER TABLE t1 ADD COLUMN b TEXT;
+BEGIN;
+UPDATE t1 SET b = REPEAT('1', 32768);
+UPDATE t1 SET a = 2;
+INSERT INTO t1 SET a = 1;
+SELECT a,LENGTH(b) FROM t1;
+DELETE FROM t1;
+COMMIT;
+--source include/wait_all_purged.inc
+DROP TABLE t1;
+
 dec $format;
 }
 disconnect analyze;

storage/innobase/row/row0ins.cc

@@ -2671,8 +2671,6 @@ row_ins_clust_index_entry_low(
 		}
 	}
 
-	if (index->is_instant()) entry->trim(*index);
-
 	if (rec_is_metadata(btr_cur_get_rec(cursor), index)) {
 		goto do_insert;
 	}
@@ -2739,6 +2737,7 @@ row_ins_clust_index_entry_low(
 		mtr_commit(&mtr);
 		mem_heap_free(entry_heap);
 	} else {
+		if (index->is_instant()) entry->trim(*index);
 do_insert:
 		rec_t*	insert_rec;