confusing block numeration on names of merged-block files

[ThomasBlock]

i had a broken merged-block file. was not easy to spot as the numeration was not clear. here my observations: ( matic )

fireeth will crash with this error:
index builder exited {"error": "processing of file \"0004933300\" failed: error processing incoming file: failed reading next dbin message: corrupt stream, did not find end of stream"}

then i can scan:

fireeth tools check merged-blocks /merged-blocks -r 4933300:4933399    
Summary:
> 🆗 No hole found

but going further see:

fireeth tools check merged-blocks /merged-blocks -r 4933300:4933600 -s
...
Block #4933499 (0fab663c4a0ebf45e664e693ee6418d1e68cfdb5cc4540c3d4879fe627a37c51) 201 transactions, 1005 calls

2023-05-16T08:41:25.636+0200 INFO (dtracing) registering development exporters from environment variables
panic: unable to decode block #4933500 (91c4abc9fd9da55554dcd7d5e94e498835850b9b7c6d1f42bc07c21f8f884cca) payload (kind: ETH, version: 3, size: 1332588, sha256: c77cda5e09bbdacf61e19343710e15507674b899ae405db0c060e657488ee9c9): unable to decode payload: proto:<C2><A0>cannot parse invalid wire-format data

-> file 0004933500 was broken. restoring from backup helped

so somebody seeing the error "processing of file 0004933300 failed" has to make the mental transfer, to check the file TWO files after the file, here 0004933500

[ThomasBlock]

found other error, better numeration
maybe not really relevant