coinstatsindex: guard input index against inconsistent undo data

Coverage report

f15fa50 - a month ago (FAILED)

Base master commit 58a7869 used for coverage and benchmarks

Failed to generate report: Essential container in task exited

Pull request run

Report ID 4241

Commit f15fa50024d2a1290f99bc177fdea1dc7603c9a3

Step Functions execution ARN arn:aws:states:ap-south-1:338220712891:execution:start-jobs-default:10f42740-2734-46fc-b73e-c58621965bc3

Coverage batch job ID Not available

Base master run

Report ID 4214

Commit 58a7869f860f022e6163dc3fae3106a0599830c5

Step Functions execution ARN arn:aws:states:ap-south-1:338220712891:execution:start-jobs-default:d589944c-d558-4ad3-b2be-f45672758157

Coverage batch job ID 29f98bed-cbe7-4f19-8948-bb1ec27e52e2