[BUG] Index 0 out of bounds for length 0 (again)

[devopg]

hi i saw that you fix it in
#7162

but in
cp-ksqldb-server:7.0.0
cp-ksqldb-cli:7.0.0

i have problem again

how to reproduce?

1. press command:
   print test from BEGINNING;
2. send json value

var msgJson = JsonSerializer.Serialize(msg);
await _producer.ProduceAsync(topic, new Message<string, string> { Key = null, Value =  msgJson});

and you take auto exit from print topic with error:

!!! Intresting moment if enter in command again print test from BEGINNING;, you will see what all okey: data exists and you stay on print command observ;

[devopg]

Omg i find problem!!! its make crush if key is empty string "" or have whitespaces " ".
I create merge request for fix it
confluentinc/confluent-kafka-dotnet#1751

[agavra]

Thanks @devopg

[mhowlett]

the proposed fix to the .net utf8 serializer isn't what we want there - should be done at a higher level instead.