invalid memory address in the addindex_test

[hawkingrei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

2. What did you expect to see? (Required)

3. What did you see instead (Required)

panic: runtime error: invalid memory address or nil pointer dereference

[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0x4739c0e]


goroutine 1874953 [running]:

github.com/pingcap/tidb/pkg/lightning/backend.(*ClosedEngine).Cleanup(0x0, {0x6f945f8, 0xc04092c460})

	pkg/lightning/backend/backend.go:405 +0x2e

github.com/pingcap/tidb/pkg/ddl/ingest.(*litBackendCtx).unsafeImportAndReset(0xc040bddb90, 0xc057f1f5f0)

	pkg/ddl/ingest/backend.go:289 +0x666

github.com/pingcap/tidb/pkg/ddl/ingest.(*litBackendCtx).Flush(0xc040bddb90, 0xa0?)

	pkg/ddl/ingest/backend.go:250 +0x875

github.com/pingcap/tidb/pkg/ddl.(*indexWriteResultSink).flush(0xc057f54790)

	pkg/ddl/backfilling_operators.go:825 +0xb3

github.com/pingcap/tidb/pkg/ddl.(*indexWriteResultSink).collectResult(0xc057f54790)

	pkg/ddl/backfilling_operators.go:804 +0x18f

golang.org/x/sync/errgroup.(*Group).Go.func1()

	external/org_golang_x_sync/errgroup/errgroup.go:78 +0x56

created by golang.org/x/sync/errgroup.(*Group).Go in goroutine 1855725

	external/org_golang_x_sync/errgroup/errgroup.go:75 +0x96

https://do.pingcap.net/jenkins/blue/organizations/jenkins/pingcap%2Ftidb%2Fghpr_check2/detail/ghpr_check2/10414/pipeline

4. What is your TiDB version? (Required)

[tangenta]

This issue should have been fixed by #53233.