Copying an Exponential Histogram results in nil pointer dereference

[mfranklin]

Component(s)

processor/metricstransform

What happened?

Description

Attempting to perform any operation that copies an exponential histogram will result in a nil pointer dereference error as the code currently calls the incorrect method on the metric.

Steps to Reproduce

Have a config that attempts an operation on an exponential histogram metric that results in a copy, such as combine

Expected Result

The metric is correctly processed and exported.

Actual Result

A nil pointer dereference error is printed to the logs.

Collector version

v0.86.0

Environment information

Environment

All

OpenTelemetry Collector configuration

processors:
  metricstransform:
    transforms:
      - include: ^<regex_for_exponential_histogram_metric>\.(?P<new_label>.+)$
        match_type: regexp
        action: combine
        new_name: new_metric

Log output

service/service.go:161	Everything is ready. Begin running and processing data.
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x2287efb]

goroutine 51 [running]:
go.opentelemetry.io/collector/pdata/pmetric.Histogram.AggregationTemporality(...)
	/go/pkg/mod/go.opentelemetry.io/collector/pdata@v1.0.0-rcv0014/pmetric/generated_histogram.go:45

Additional context

No response

[github-actions]

Pinging code owners:

• processor/metricstransform: @dmitryax

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[crobert-1]

I'm not super familiar with this component, but removing needs triage as the PR shows the bug pretty clearly. Thanks for filing and fixing @mfranklin!