Bug 251044 – Fix clang-tidy bugprone-infinite-loop warnings in WebCore::AudioSampleDataSource::pullAvailableSamplesAsChunks()

• Component: Media
• Status: NEW

[David Kilzer (:ddkilzer)]

Fix clang-tidy bugprone-infinite-loop warnings in WebCore::AudioSampleDataSource::pullAvailableSamplesAsChunks().

In `Source/WebCore/platform/audio/cocoa/AudioSampleDataSource.mm`, the following `while()` loops can result in infinite loops if `sampleCountPerChunk` is zero (since there is no check that `sampleCountPerChunk` is non-zero):

```
bool AudioSampleDataSource::pullAvailableSamplesAsChunks(AudioBufferList& buffer, size_t sampleCountPerChunk, uint64_t timeStamp, Function<void()>&& consumeFilledBuffer)
{
    [...]
    if (m_muted) {
        AudioSampleBufferList::zeroABL(buffer, sampleCountPerChunk * m_outputDescription->bytesPerFrame());
        while (endFrame - startFrame >= sampleCountPerChunk) {
            consumeFilledBuffer();
            startFrame += sampleCountPerChunk;
        }
        return true;
    }

    while (endFrame - startFrame >= sampleCountPerChunk) {
        m_ringBuffer->fetch(&buffer, sampleCountPerChunk, startFrame, CARingBuffer::Copy);
        consumeFilledBuffer();
        startFrame += sampleCountPerChunk;
    }
    return true;
}
```
<https://github.com/WebKit/WebKit/blob/main/Source/WebCore/platform/audio/cocoa/AudioSampleDataSource.mm#L317>

Found by clang static analyzer.

[Radar WebKit Bug Importer]

<rdar://problem/104575403>

[David Kilzer (:ddkilzer)]

Pull request: https://github.com/WebKit/WebKit/pull/9001