Fix instant ADD after instant DROP

row_metadata_to_tuple(), row_rec_to_index_entry_impl():
Add the parameter "pad" to determine whether
the tuple should be padded to the index fields (on ALTER TABLE it should),
or whether it should remain at its original size (on rollback).

trx_undo_page_report_modify(): Avoid out-of-bounds access to record fields.

row_quiesce_write_index_fields(): Do not crash when the table contains
an instantly dropped column.

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

@@ -56,6 +56,7 @@ ROLLBACK;
 InnoDB		0 transactions not purged
 INSERT INTO t2 VALUES (64,42,'De finibus bonorum'), (347,33101,' et malorum');
 connect ddl, localhost, root;
+ALTER TABLE t2 DROP COLUMN c3;
 SET DEBUG_SYNC='innodb_alter_inplace_before_commit SIGNAL ddl WAIT_FOR ever';
 ALTER TABLE t2 ADD COLUMN (c4 TEXT NOT NULL DEFAULT ' et malorum');
 connection default;
@@ -69,12 +70,12 @@ SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
 SELECT * FROM t1;
 id	c2
 SELECT * FROM t2;
-id	c2	c3
-2	1	De finibus bonorum
-16	1551	Omnium enim rerum
-64	42	De finibus bonorum
-128	1571	 principia parva sunt
-347	33101	 et malorum
+id	c2
+2	1
+64	42
+16	1551
+128	1571
+347	33101
 BEGIN;
 INSERT INTO t1 SET id=1;
 DELETE FROM t2;
@@ -87,26 +88,27 @@ header=0x010000030074 (id=0x696e66696d756d00)
 header=0x010008030000 (id=0x73757072656d756d00)
 t2 clustered index root page(type 18):
 N_RECS=6; LEVEL=0
-header=0x010000030088 (id=0x696e66696d756d00)
-header=0x1000100b00b9 (id=0x80000000,
- DB_TRX_ID=0x000000000000,
- DB_ROLL_PTR=0x80000000000000,
+header=0x01000003008f (id=0x696e66696d756d00)
+header=0x3000100c00d4 (id=0x80000000,
+ DB_TRX_ID=0x000000000042,
+ DB_ROLL_PTR=0x060000013a03a8,
+ BLOB=0x0000000600000006000000260000000000000008,
  c2=NULL(4 bytes),
  c3=0x44652066696e6962757320626f6e6f72756d)
-header=0x0000180900d9 (id=0x80000002,
+header=0x0000180900f4 (id=0x80000002,
  DB_TRX_ID=0x000000000000,
  DB_ROLL_PTR=0x80000000000000,
  c2=0x80000001)
-header=0x0000200b013e (id=0x80000010,
+header=0x0000200b0124 (id=0x80000010,
  DB_TRX_ID=0x000000000000,
  DB_ROLL_PTR=0x80000000000000,
  c2=0x8000060f,
  c3=0x4f6d6e69756d20656e696d20726572756d)
-header=0x00003009010a (id=0x80000040,
+header=0x000028090144 (id=0x80000040,
  DB_TRX_ID=0x000000000000,
  DB_ROLL_PTR=0x80000000000000,
  c2=0x8000002a)
-header=0x0000280b015e (id=0x80000080,
+header=0x0000300b0179 (id=0x80000080,
  DB_TRX_ID=0x000000000000,
  DB_ROLL_PTR=0x80000000000000,
  c2=0x80000623,
@@ -133,7 +135,6 @@ Table	Create Table
 t2	CREATE TABLE `t2` (
   `id` int(11) NOT NULL,
   `c2` int(11) DEFAULT NULL,
-  `c3` text NOT NULL DEFAULT 'De finibus bonorum',
   PRIMARY KEY (`id`),
   UNIQUE KEY `c2` (`c2`)
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=REDUNDANT

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

@@ -74,6 +74,7 @@ ROLLBACK;
 INSERT INTO t2 VALUES (64,42,'De finibus bonorum'), (347,33101,' et malorum');
 
 connect ddl, localhost, root;
+ALTER TABLE t2 DROP COLUMN c3;
 SET DEBUG_SYNC='innodb_alter_inplace_before_commit SIGNAL ddl WAIT_FOR ever';
 --send
 ALTER TABLE t2 ADD COLUMN (c4 TEXT NOT NULL DEFAULT ' et malorum');
@@ -124,6 +125,7 @@ for (my $offset= 0x65; $offset;
     my $n_fields= unpack("n", substr($page,$offset-4,2)) >> 1 & 0x3ff;
     my $start= 0;
     my $name;
+    if (unpack("C", substr($page,$offset-3,1)) & 1) {
 	for (my $i= 0; $i < $n_fields; $i++) {
 	    my $end= unpack("C", substr($page, $offset-7-$i, 1));
 	    print ",\n " if $i;
@@ -135,6 +137,27 @@ for (my $offset= 0x65; $offset;
 	    }
 	    $start= $end & 0x7f;
 	}
+    } else {
+	for (my $i= 0; $i < $n_fields; $i++) {
+	    my $end= unpack("n", substr($page, $offset-8-2*$i, 2));
+	    print ",\n " if $i;
+	    if ($i > 2 && !(~unpack("C",substr($page,$offset-6,1)) & 0x30)) {
+		if ($i == 3) {
+		    print "BLOB=";
+		} else {
+		    print "$fields[$i - 1]=";
+		}
+	    } else {
+		print "$fields[$i]=";
+	    }
+	    if ($end & 0x8000) {
+		print "NULL(", ($end & 0x7fff) - $start, " bytes)"
+	    } else {
+		print "0x", unpack("H*", substr($page,$offset+$start,($end-$start) & 0x3fff))
+	    }
+	    $start= $end & 0x3fff;
+	}
+    }
     print ")\n";
 }
 close(FILE) || die "Unable to close $file\n";

storage/innobase/btr/btr0cur.cc

@@ -4732,9 +4732,10 @@ btr_cur_pessimistic_update(
 		ut_ad(update->is_metadata());
 		ut_ad(flags & BTR_NO_LOCKING_FLAG);
 		ut_ad(index->is_instant());
-		new_entry = row_metadata_to_tuple(rec, index, *offsets,
+		new_entry = row_metadata_to_tuple(
+			rec, index, *offsets,
 			&n_ext, entry_heap,
-						  update->info_bits);
+			update->info_bits, !thr_get_trx(thr)->in_rollback);
 		ut_ad(new_entry->n_fields
 		      == ulint(index->n_fields)
 		      + update->is_alter_metadata());

storage/innobase/include/row0row.h

@@ -238,7 +238,8 @@ row_rec_to_index_entry(
 @param[in]	offsets		rec_get_offsets(rec)
 @param[out]	n_ext		number of externally stored fields
 @param[in,out]	heap		memory heap for allocations
-@param[in]	info_bits	the info_bits after an update */
+@param[in]	info_bits	the info_bits after an update
+@param[in]	pad		whether to pad to index->n_fields */
 dtuple_t*
 row_metadata_to_tuple(
 	const rec_t*		rec,
@@ -246,7 +247,8 @@ row_metadata_to_tuple(
 	const ulint*		offsets,
 	ulint*			n_ext,
 	mem_heap_t*		heap,
-	ulint			info_bits)
+	ulint			info_bits,
+	bool			pad)
 	MY_ATTRIBUTE((nonnull,warn_unused_result));
 
 /*******************************************************************//**

storage/innobase/row/row0quiesce.cc

@@ -73,17 +73,16 @@ row_quiesce_write_index_fields(
 			return(DB_IO_ERROR);
 		}
 
+		const char* field_name = field->name ? field->name : "";
 		/* Include the NUL byte in the length. */
-		ib_uint32_t	len = static_cast<ib_uint32_t>(strlen(field->name) + 1);
-		ut_a(len > 1);
-
+		ib_uint32_t	len = static_cast<ib_uint32_t>(strlen(field_name) + 1);
 		mach_write_to_4(row, len);
 
 		DBUG_EXECUTE_IF("ib_export_io_write_failure_10",
 				close(fileno(file)););
 
 		if (fwrite(row, 1,  sizeof(len), file) != sizeof(len)
-		    || fwrite(field->name, 1, len, file) != len) {
+		    || fwrite(field_name, 1, len, file) != len) {
 
 			ib_senderrf(
 				thd, IB_LOG_LEVEL_WARN, ER_IO_WRITE_ERROR,

storage/innobase/row/row0row.cc

@@ -709,6 +709,7 @@ row_build_w_add_vcol(
 @param[out]	n_ext		number of externally stored columns
 @param[in,out]	heap		memory heap for allocations
 @param[in]	info_bits	(only used if mblob=2)
+@param[in]	pad		(only used if mblob=2)
 @return index entry built; does not set info_bits, and the data fields
 in the entry will point directly to rec */
 template<bool metadata, int mblob = 0>
@@ -720,7 +721,8 @@ row_rec_to_index_entry_impl(
 	const ulint*		offsets,
 	ulint*			n_ext,
 	mem_heap_t*		heap,
-	ulint			info_bits = 0)
+	ulint			info_bits = 0,
+	bool			pad = false)
 {
 	ut_ad(rec != NULL);
 	ut_ad(heap != NULL);
@@ -741,9 +743,15 @@ row_rec_to_index_entry_impl(
 		ut_ad(info_bits == REC_INFO_METADATA_ALTER
 		      || info_bits == REC_INFO_METADATA_ADD);
 		ut_ad(rec_len <= ulint(index->n_fields + got));
-		rec_len += !got && info_bits == REC_INFO_METADATA_ALTER;
+		if (pad) {
+			rec_len = ulint(index->n_fields)
+				+ (info_bits == REC_INFO_METADATA_ALTER);
+		} else if (!got && info_bits == REC_INFO_METADATA_ALTER) {
+			rec_len++;
+		}
 	} else {
 		ut_ad(info_bits == 0);
+		ut_ad(!pad);
 	}
 	dtuple_t* entry = dtuple_create(heap, rec_len);
 	dfield_t* dfield = entry->fields;
@@ -825,6 +833,14 @@ row_rec_to_index_entry_impl(
 		for (; i < rec_len; i++, dfield++) {
 			dict_col_copy_type(dict_index_get_nth_col(index, j++),
 					   &dfield->type);
+			if (mblob == 2 && pad
+			    && i >= rec_offs_n_fields(offsets)) {
+				field = index->instant_field_value(j - 1,
+								   &len);
+				dfield_set_data(dfield, field, len);
+				continue;
+			}
+
 			field = rec_get_nth_field(rec, offsets, i, &len);
 			dfield_set_data(dfield, field, len);
 
@@ -913,7 +929,8 @@ row_rec_to_index_entry(
 @param[in]	offsets		rec_get_offsets(rec)
 @param[out]	n_ext		number of externally stored fields
 @param[in,out]	heap		memory heap for allocations
-@param[in]	info_bits	the info_bits after an update */
+@param[in]	info_bits	the info_bits after an update
+@param[in]	pad		whether to pad to index->n_fields */
 dtuple_t*
 row_metadata_to_tuple(
 	const rec_t*		rec,
@@ -921,7 +938,8 @@ row_metadata_to_tuple(
 	const ulint*		offsets,
 	ulint*			n_ext,
 	mem_heap_t*		heap,
-	ulint			info_bits)
+	ulint			info_bits,
+	bool			pad)
 {
 	ut_ad(info_bits == REC_INFO_METADATA_ALTER
 	      || info_bits == REC_INFO_METADATA_ADD);
@@ -939,7 +957,7 @@ row_metadata_to_tuple(
 	dtuple_t* entry = info_bits == REC_INFO_METADATA_ALTER
 		|| rec_is_alter_metadata(copy_rec, *index)
 		? row_rec_to_index_entry_impl<true,2>(
-			copy_rec, index, offsets, n_ext, heap, info_bits)
+			copy_rec, index, offsets, n_ext, heap, info_bits, pad)
 		: row_rec_to_index_entry_impl<true>(
 			copy_rec, index, offsets, n_ext, heap);
 

storage/innobase/trx/trx0rec.cc

@@ -1165,7 +1165,8 @@ trx_undo_page_report_modify(
 				return 0;
 			}
 
-			if (rec_offs_nth_extern(offsets, pos)) {
+			if (rec_offs_n_fields(offsets) > pos
+			    && rec_offs_nth_extern(offsets, pos)) {
 				ut_ad(col || pos == index->first_user_field());
 				ut_ad(col || update->is_alter_metadata());
 				ut_ad(col