[BUG]: NoMethodError in extract_trace_id! when extract_tags rescue returns Logger#warn result (true)

[eliasousa]

Tracer Version(s)

2.29.0, 2.31.0

Ruby Version(s)

3.4.5

Relevent Library and Version(s)

No response

Bug Report

The rescue block in Datadog::Tracing::Distributed::Datadog#extract_tags implicitly returns true (the return value of Logger#warn) instead of nil when a decoding error occurs.
This true is passed to extract_trace_id!, which calls .delete on it, raising a NoMethodError.

The same implicit return pattern exists in the inject_tags! rescue block, though it doesn't currently trigger a downstream error.

Expected behavior

#extract returns a valid TraceDigest (ignoring the malformed tags gracefully), and a warning is logged.

Actual behavior

  NoMethodError: undefined method 'delete' for true

  raised from extract_trace_id! (https://github.com/DataDog/dd-trace-rb/blob/e3406de/lib/datadog/tracing/distributed/datadog.rb#L117) because extract_tags returned true instead
   of nil.

Errors with stack traces

  NoMethodError: undefined method 'delete' for true
    from lib/datadog/tracing/distributed/datadog.rb:117:in 'extract_trace_id!'
    from lib/datadog/tracing/distributed/datadog.rb:73:in 'extract'

Impact

In our production environment, this generates ~30,000+ error logs per day. Any application receiving requests with malformed x-datadog-tags headers hits this.

Reproduction Code

propagator = Datadog::Tracing::Distributed::Datadog.new(
  fetcher: Datadog::Tracing::Distributed::Fetcher
)

propagator.extract({
  "x-datadog-trace-id" => "1234567890",
  "x-datadog-parent-id" => "9876543210",
  "x-datadog-tags" => "malformed_value"
})

Configuration Block

  Datadog.configure do |c|
    c.tracing.enabled = true
    c.tracing.log_injection = true
    c.tracing.instrument :rack, quantize: { base: :show, query: { show: :all, obfuscate: :internal } }
    c.tracing.instrument :rails
    c.tracing.contrib.global_default_service_name.enabled = true
  end

Error Logs

Operating System

Linux x86_64 6.19.6-arch1-1 GNU/Linux

How does Datadog help you?

No response