improve logging and usability for low privileged users

[vikerup]

Fixes for Low-Privilege User Support

FolderOrFileDeleteToSystem/FolderOrFileDeleteToSystem.cpp

Fix 1 — Wrong handle check in stage1()

CreateFile returns INVALID_HANDLE_VALUE on failure, not NULL. The original check
if (!hFileDummy) never fired on failure, causing an infinite loop in
GetFinalPathNameByHandle. Fixed to:

if (hFileDummy == INVALID_HANDLE_VALUE)

Fix 2 — ALLUSERS property malformed on command line

ALLUSERS= followed by a space caused the MSI parser to consume the next property
(TARGETDIR=...) as the value of ALLUSERS, giving it a truthy non-"2" value which
the installer engine canonicalized to 1 (per-machine), triggering error 1603.
Fixed by quoting the empty string with \"\" in all three MSI calls:

// install()
L"ACTION=INSTALL ALLUSERS=\"\" TARGETDIR=" + installPath

// installWithRollback()
L"ACTION=INSTALL ALLUSERS=\"\" ERROROUT=1 TARGETDIR=" + installPath

// uninstall()
L"REMOVE=ALL ALLUSERS=\"\""

---

SystemCmdLauncher/dllmain.cpp

Fix 1 — CRT dependency caused load failure

std::make_unique (<memory>), memset, and wcslen all pull in the MSVC CRT
(VCRUNTIME140.DLL), which may not be present on the target. Removed <memory>,
replaced std::make_unique with HeapAlloc/HeapFree, and replaced memset zero-
initialization with C++ value-initialization (= {}).

Also set Runtime Library to /MT (Multi-threaded static) in project properties:

Properties - C/C++ - Code Generation - Runtime Library - Multi-threaded (/MT)

Fix 2 — Added rundll32-callable export for manual testing

extern "C" __declspec(dllexport) void CALLBACK Test(HWND, HINSTANCE, LPSTR, int)
{
    DoIt();
}

Test with:

rundll32.exe "C:\Program Files\Common Files\microsoft shared\ink\HID.DLL",Test