Fix crashes in SndioCapture::recordProc (#594)

* Fix crashes while capturing audio using openal with sndio backend.

* Proper function for mFds preallocation.
Now it is checked whether the returned value of the sin_nfds() function is not a negative number.

1 files changed, 9 insertions, 0 deletions

diff --git a/alc/backends/sndio.cpp b/alc/backends/sndio.cpp
index 6852e01a..2c3eb3c7 100644
--- a/alc/backends/sndio.cpp
+++ b/alc/backends/sndio.cpp
@@ -311,6 +311,15 @@ int SndioCapture::recordProc()
 
     const uint frameSize{mDevice->frameSizeFromFmt()};
 
+    int nfds_pre{sio_nfds(mSndHandle)};
+    if (nfds_pre <= 0)
+    {
+        mDevice->handleDisconnect("Incorrect return value from sio_nfds(): %d", nfds_pre);
+        return 1;
+    }
+
+    mFds.resize(nfds_pre);
+
     while(!mKillNow.load(std::memory_order_acquire)
         && mDevice->Connected.load(std::memory_order_acquire))
     {