Divide-by-zero in rd_hdr_histogram_new()

[vdeters]

Read the FAQ first: https://github.com/confluentinc/librdkafka/wiki/FAQ

Do NOT create issues for questions, use the discussion forum: https://github.com/confluentinc/librdkafka/discussions

Description

Divide-by-zero thrown, presumably caused by taking the logarithm of 0, which is passed in as parameter minValue.

How to reproduce

• Build with WITH_HDRHISTOGRAM enabled.
• Leave global parameter enable.metrics.push at its default value of true.
• Connect to any broker.

IMPORTANT: Always try to reproduce the issue on the latest released version (see https://github.com/confluentinc/librdkafka/releases), if it can't be reproduced on the latest version the issue has been fixed.

Checklist

IMPORTANT: We will close issues where the checklist has not been completed.

Please provide the following information:

• librdkafka version (release number or git tag): 2.6.1 or 2.8.0
• Apache Kafka version: Confluent 7.5.4
• librdkafka client configuration: metadata.broker.list=trcv002.trc.sas.com:9092,group.id=163dd99c-0b48-43a9-b2e8-fb3c935398c7,enable.partition.eof=true,log.connection.close=false,default_topic_conf={auto.offset.reset=smallest}
• Operating system: Centos 8(x64)
• Provide logs (with debug=.. as necessary) from librdkafka
• Provide broker log excerpts
• Critical issue

[vdeters]

Also, floating point exceptions must be enabled to reproduce. This is why sample code and basic tests don’t fail like this.