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Preserved Quirks

This is the condensed index of all 23 quirks documented in QUIRKS.md. These are not bugs in our recreation — they are faithful reproductions of the original binary's behavior. If you're building a "remix" with fixes, use this (and QUIRKS.md) as the checklist.

Do not "fix" these

Recreating, keeping, and extending the codebase to match these behaviors is correct and expected. Only change them when an explicit remix/fix pass is requested.

Exception & crash handling​

1. Double-Exception Protection Pattern (VEH + SEH)​

src/MovieMaker/main.cpp:14-30 — The launcher registers a Vectored Exception Handler catching C++ exception code 0xe06d7363 and subcodes 0x19930520 (__CT typeName), 0x19930521 (bad_typeid), 0x19930522 (bad_cast), plus the undocumented 0x01994000. The VEH returns EXCEPTION_EXECUTE_HANDLER, then the outer __except catches the unwind — silently swallowing RTTI failures that should probably be fatal.

8. Exception Objects Use Process Heap (Not CRT Heap)​

src/WLXPhotoBase/WLXPhotoBase.cpp:179-199 — Exception::operator new allocates from GetProcessHeap() and raises EXCEPTION_NONCONTINUABLE_EXCEPTION on failure instead of throwing std::bad_alloc. Mixing heap allocators can crash if CRT frees process-heap memory.

21. HMREngine Error Handling Silently Swallows Failures​

HMREngine logs-and-continues on non-fatal failures — failures disappear rather than propagate.

22. Null Pointer Dereference in Transport Controls​

A reachable null-deref path in the transport controls (specific seek-while-stopped sequence). Reproduced faithfully; surrounding behavior is contract-pinned.

Identity & branding​

2. "Sundance" Codename Leaked Into Runtime Objects​

MovieMakerCore.cpp:427-432 — the single-instance mutex is named Global\WindowsLiveMovieMaker_Sundance_SingleInstance (visible across all Terminal Services sessions; the internal codename persists in a system object). Any program creating this mutex blocks Movie Maker from launching.

7. "SkyDrive" Branding (Historical Anachronism)​

UIBehaviorClasses.h — PublishDialogSkyDriveBehavior targets "SkyDrive", renamed to OneDrive in 2014. The publish dialog targets a service that no longer exists under this name.

COM & GUID oddities​

3. Null CLSID for MovieMakerCore.dll​

src/common.h:163 — CLSID_MovieMakerCore is all zeros. The DLL is loaded via LoadLibrary/GetProcAddress, so it's never used — but COM-registering it would register a null GUID.

4. Deterministic Pseudo-GUIDs for COM Objects​

ComFactory.h:33-47 — hand-crafted sequential placeholder GUIDs ({A1B2C3D4-E5F6-...}) for reconstructed COM classes; the originals were never extracted. They will conflict with any real COM registration.

16. IsolationAwareTaskDialog​

External/UIControlsStub.h — RTTI ?AVIsolationAwareTaskDialog@@ references a task dialog type aware of manifest-based side-by-side isolation that doesn't exist in modern SDKs.

Rendering & UI​

6. Removed Win10 Ribbon SDK APIs​

UI/Ribbon/RibbonApp.cpp — the original used IUIFramework::RegisterUICommand, UI_VIEWVERB_EXECUTE, and UI_PKEY_* keys removed from the Windows 10 SDK; IID_IUICommandHandler had to be defined manually. The Ribbon integration silently fails where the APIs are missing — as the original would today.

9. D3D11 Single-Threaded Flag for a Video Editor​

dllmain.cpp — D3D11 device creation passes the single-threaded flag (no D3D11_CREATE_DEVICE_THREAD_SAFE) despite the app being multi-threaded: a latent race the original shipped with.

12. Vista Basic Ribbon Workaround​

src/WTL/atlribbon.h:2215 — SetWindowRgn(NULL, TRUE) works around a Vista Basic theme rendering bug; a no-op on modern Windows that wastes a call.

13. 118 Dummy Texture Codec Classes​

HMREngine/DXResources/TextureCodecs.h — ~118 D3DX11 texture codec classes existing solely to generate unique RTTI entries; Encode/Decode return E_NOTIMPL. Binary bloat with no functional purpose.

17. Custom STL-like Container Library​

DataStructs/IntSet.h — a custom STL-like container library (IntSet, StringSet) instead of CRT STL, duplicating container functionality with different semantics.

Architecture choices​

10. Non-Contiguous Command IDs​

MovieMakerCore.cpp:201-213 — command IDs with large gaps (ID_APP_IMPORT 0xE101, ID_APP_UNDO 0xE12B, ID_APP_DELETE 0xE200, ...), likely IDs of removed features never reclaimed.

11. Delay-Loaded DLLs That No Longer Exist​

WLXMediaPublishSubscribe.cpp:11-15 — WLXPhotoSqm.dll, DmxBici.dll, wlidcli.dll, uxcore.dll are delay-loaded but not shipped on modern Windows; without delay-load exception handling the app would crash at startup.

14. Local Classes Nested Inside Methods (RTTI)​

SundanceAppMain.cpp:39-44 — RTTI @?1?? names reveal C++03-style "lambda objects" (local classes inside member functions) — lambdas didn't exist in the original's toolchain.

15. Global Singleton Architecture​

dllmain.cpp:66, SundanceAppMain.cpp:50 — CAppModule _Module and g_pSundanceAppMain wire the entire app through file-scope singletons with no dependency injection: hard to unit-test, hidden coupling.

18. 92 Transition/Effect Animation Classes​

src/WLXPipetran/WLXPipetran.h:4-7 — 92 RTTI transition/effect classes (StarWipeTransition, BowTieWipeTransition, ClockWipeTransition, PixelateTransition, ...), of which 22 were never fully implemented in the original — shipped as stubs.

20. WARP Fallback as Default Rendering Path​

dllmain.cpp:200-243 — initialization tries hardware D3D11, then falls back to WARP with feature levels 11.1 → 9.1. Without hardware support the entire pipeline runs in software — extremely slow for video editing.

Legacy & leaks​

19. Legacy Project Format Support​

UI/Legacy/LegacyProject.cpp etc. — full backward compatibility with an older project format (LegacyExtent, LegacyTextExtent, ComplexProperty, SingleProperty, TransformProperty) — dead code in the 2012 version, but still compiled and shipped.

23. Memory Leak in Serialization Writer​

The .wlmp serialization writer leaks memory on an error path — reproduced faithfully (the contract suite documents the non-leaking paths around it).

5. HMREngine Redefines Windows SDK Error Macros​

HMREngine/HMREngine.h:111-182 — the engine temporarily redefines SDK error macros and restores them. Never add includes in that span; it breaks the restore logic.

How to use this list​

  • Contributors: treat these as pinned behavior. If a change alters one of them, that's a remix decision, not a bug fix.
  • Remixers: each quirk above is a candidate fix — read the full entry in QUIRKS.md (file/line references included) before changing it, and check the contract suite for pinned behavior around it.