dm panic due to empty column name of unique index

[GMHDBJD]

What did you do?

start dm task

What did you expect to see?

task runs well

What did you see instead?

DM panic:
[golang.org/x/sync@v0.1.0/errgroup/errgroup.go:75](http://golang.org/x/sync@v0.1.0/errgroup/errgroup.go:75) +0x64
[golang.org/x/sync/errgroup.(*Group).Go.func1()](http://golang.org/x/sync/errgroup.(*Group).Go.func1())
        [github.com/pingcap/tiflow/dm/pkg/checker/worker_pool.go:85](http://github.com/pingcap/tiflow/dm/pkg/checker/worker_pool.go:85) +0xd3
[github.com/pingcap/tiflow/dm/pkg/checker](http://github.com/pingcap/tiflow/dm/pkg/checker).(*WorkerPool[...]).Go.func1()
        [github.com/pingcap/tiflow/dm/pkg/checker/table_structure.go:189](http://github.com/pingcap/tiflow/dm/pkg/checker/table_structure.go:189) +0x7ed
[github.com/pingcap/tiflow/dm/pkg/checker.(*tablesCheckerWorker).handle](http://github.com/pingcap/tiflow/dm/pkg/checker.(*tablesCheckerWorker).handle)(0xc001a70300, {0x493ce28, 0xc0011cc5f0}, 0xc0011cdc70)
        [github.com/pingcap/tiflow/dm/pkg/checker/table_structure.go:338](http://github.com/pingcap/tiflow/dm/pkg/checker/table_structure.go:338) +0x56c
[github.com/pingcap/tiflow/dm/pkg/checker.(*TablesChecker).checkAST](http://github.com/pingcap/tiflow/dm/pkg/checker.(*TablesChecker).checkAST)(0xc0018583e8?, 0xc0011fd450, 0xc0011fdad0, {0x0, 0x0, 0x0})
        [github.com/pingcap/tiflow/dm/pkg/checker/table_structure.go:404](http://github.com/pingcap/tiflow/dm/pkg/checker/table_structure.go:404) +0x2694
[github.com/pingcap/tiflow/dm/pkg/checker.(*TablesChecker).checkTableStructurePair](http://github.com/pingcap/tiflow/dm/pkg/checker.(*TablesChecker).checkTableStructurePair)(0xc001935c48?, 0xc0011fd450, 0xc0011fdad0, {0x0, 0x0, 0xc000098c00?})
        [github.com/pingcap/tiflow/dm/pkg/checker/utils.go:215](http://github.com/pingcap/tiflow/dm/pkg/checker/utils.go:215)
[github.com/pingcap/tiflow/dm/pkg/checker.getPKAndUK(...)](http://github.com/pingcap/tiflow/dm/pkg/checker.getPKAndUK(...))
goroutine 864 [running]:
[signal SIGSEGV: segmentation violation code=0x1 addr=0x98 pc=0x3347634]
panic: runtime error: invalid memory address or nil pointer dereference

Versions of the cluster

DM version (run dmctl -V or dm-worker -V or dm-master -V):

master

Upstream MySQL/MariaDB server version:

(paste upstream MySQL/MariaDB server version here)

Downstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

(paste TiDB cluster version here)

How did you deploy DM: tiup or manually?

(leave TiUP or manually here)

Other interesting information (system version, hardware config, etc):

>
>

current status of DM cluster (execute query-status <task-name> in dmctl)

(paste current status of DM cluster here)