Fix/memory resource safety

[gfnord]

Summary

A set of memory- and resource-safety fixes across four files. No behavioural change on the success path; each change closes a leak, a use-after-free risk, or an uninitialized read on a failure/exception path.

Changes

Common/Common.cpp — Update check buffer exception safety

The 255-byte char buffer used by CUpdateCheck was allocated with raw new[] and freed only after several std::string operations that can throw bad_alloc on OOM. Switched to std::unique_ptr<char[]> so the buffer cannot leak on the exception path. The 254-byte GitHub-API read through the same WinINet handles is unchanged.

LightFX/LightFX.cpp — Init resource cleanup on failure paths

Two fixes in LFX_Initialize:

• NODEVS path: when no devices are detected, the previous code returned LFX_ERROR_NODEVS leaving the worker thread, its two events, and afx_dev allocated for process lifetime. Now the NODEVS branch stops the worker (SetEvent + WaitForSingleObject + CloseHandle on the thread and both events) and then deletes afx_dev. CLightsProc at LightFX.cpp:54 dereferences afx_dev with no NULL guard, so the thread is stopped before afx_dev is freed, and a comment documents the invariant so future cleanup passes do not reorder it into a use-after-free.
• CreateThread failure path: if CreateThread in the same block returned NULL, the two CreateEvent handles created moments earlier leaked and afx_dev was left orphaned. The new if (!updateThread) branch closes both events, NULLs them, frees afx_dev, and returns LFX_ERROR_NOINIT.

alienfx-gui/HapticsDialog.cpp — Drop redundant DeleteDC

DrawFreq() already returns the window DC via ReleaseDC(hysto, hdc_r), so the following DeleteDC(hdc_r) was a no-op on an already-released handle (DeleteDC is for CreateCompatibleDC results, not GetDC results). Removed the redundant line.

alienfx-gui/WSAudioIn.cpp — Initialize COM enumerator, RAII FFT buffers

Two fixes:

• GetDefaultMultimediaDevice() declared IMMDeviceEnumerator* pEnumerator uninitialized, then tested it with if (pEnumerator) after CoCreateInstance. If CoCreateInstance failed, the out-param was not guaranteed NULL and the check read indeterminate stack memory. Now initialized to NULL.
• FFTProc() allocated kiss_cfg + three new[] arrays without rollback; a bad_alloc in any later allocation leaked the earlier ones, and kiss_fftr_alloc returning NULL caused a NULL dereference in kiss_fftr below. Switched the three arrays to std::unique_ptr<T[]>, moved kiss_fftr_alloc after them, and added a NULL check that returns early. Updated the kiss_fftr call site to use .get(). Removed the three matching delete[] lines at function exit; kiss_fft_free is retained.

Notes

• No public API or success-path behaviour changes.
• Resource lifetimes are now exception-safe where they were not before.