CNA-BUG-149: Microphone::Start reports Started even when the capture device could not be opened

CNA snapshot 009d40f5  ·  Known Issues › Current bugs  ·  source links pinned to 009d40f5

Start swallows every exception from opening the device and ignores an unusable negotiated format, then sets State to Started; XNA's Start surfaces the native error as an exception.

Identifier

CNA-BUG-149

Category

Bug

Subsystem

Audio & media

Status

Open

Verified against

CNA 009d40f5 (009d40f5dd085c4e674d3479675fac84b12b3e0a)

Severity

Low (a triage suggestion, not a project priority)

Evidence basis

Source-verified: read at TARGET, not executed

Tests touching this area

Yes: see Current tests

Affected contract

Microphone::Start() and Microphone::getStateProperty()

Expected behaviour

XNA 4.0's Microphone.Start (IL) calls the native start and passes its result to Helpers.ThrowExceptionFromErrorCode, so a device that cannot start raises an exception (for example NoMicrophoneConnectedException) and State does not become Started.

Actual behaviour at TARGET

Microphone::Start in Microphone.cpp opens the device inside catch (...) {} (“FNA ignores native start failure and still transitions public state”), closes it without error if the negotiated format is not 16-bit mono, and then unconditionally sets state_ = MicrophoneState::Started. The caller sees a started microphone that never delivers data.

Source locations

• modules/audio/src/Xna/Microphone.cpp — Microphone::Start: catch (...) and unconditional Started

Evidence

Checked by reading at 009d40f5 against the XNA 4.0 IL of Microphone.Start; not executed. The code follows FNA deliberately; this entry applies CNA's rule that XNA's contract wins where FNA differs.

Focused reproduction

No focused reproduction is known. Nothing has been invented here; the evidence above is what exists.

Current tests

MicrophoneTests.cpp and MicrophoneStateTests.cpp cover state transitions with working or absent providers; none asserts the failure path.

Regression test

A canned recording provider whose Open throws, expecting an exception and State Stopped.

Blast radius

Voice or audio-capture features on machines whose device fails to open; the game waits for data that never arrives.

Workaround

Check that GetData delivers data within a timeout after Start.