999072 - MediaManager GetCharPref("media.video_loopback_dev") leaks strings in DEBUG build

Status: RESOLVED FIXED

(Core :: WebRTC: Audio/Video, defect)

Description

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

From http://hg.mozilla.org/mozilla-central/rev/622e6c1191eb :
> +  char* loopbackAudioDevice = nullptr;
> +  char* loopbackVideoDevice = nullptr;
> +  nsresult rv;
> +#ifdef DEBUG
> +  // Check if the preference for using loopback devices is enabled.
> +  nsCOMPtr<nsIPrefService> prefs = do_GetService("@mozilla.org/preferences-service;1", &rv);
> +  if (NS_SUCCEEDED(rv)) {
> +    nsCOMPtr<nsIPrefBranch> branch = do_QueryInterface(prefs);
> +    if (branch) {
> +      branch->GetCharPref("media.audio_loopback_dev", &loopbackAudioDevice);
> +      branch->GetCharPref("media.video_loopback_dev", &loopbackVideoDevice);
> +    }
> +  }
> +#endif

GetCharPref returns an NS_strdup() which is never released (twice here per call).
Should use getter_Copies.

It only leaks if you set one or both of the loopback values in about:config - they aren't normally set - and only in DEBUG.

Comment 1

[(not currently active) Ted Mielczarek]

Attachment: fix leak in MediaManager loopback device pref checks, enable them for non-DEBUG

This fixes the leak by way of switching to Preferences::GetCString, and also enables this code in non-debug builds since I want to use it for bug 815002.

Comment 2

[(not currently active) Ted Mielczarek]

https://hg.mozilla.org/integration/mozilla-inbound/rev/c589ff189068

Comment 3

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/c589ff189068