Fix: Null-guards and unmanaged memory leaks

[freakdaniel]

Summary

Fixed critical memory safety and correctness bugs in InfiniFrame.Native and managed interop layer, addressing null pointer dereferences, memory corruption, memory leaks, and platform-specific build issues

Type of Change

• Bug fix (non-breaking change fixing an issue)

Affected Modules / Scope

• InfiniFrame
• InfiniFrame.Native
• InfiniFrame.Shared

Changes Introduced

• Added heap-allocated string copies for C API getters (GetUserAgent, GetTitle, GetIconFileName) to match documented ownership contract
• Added platform-specific AllocateStringCopy helper for safe string allocation across Windows/Linux/macOS
• Fixed EventSubscription token sequence to start from 1 instead of 0, preventing first subscription from being unsubscribable
• Fixed Linux/macOS CMake configuration by moving CMAKE_OSX_ARCHITECTURES to macOS-only section
• Added null-guard for WM_ACTIVATE message handler to prevent crash when hwnd map lookup fails
• Fixed bool/BOOL type mismatch in WebView2 getters by using intermediate BOOL variable for safe 4-byte to 1-byte conversion
• Added null-checks for RefreshImmersiveColorPolicyState and GetIsImmersiveColorUsingHighContrast in IsColorSchemeChange
• Implemented FreeCustomSchemeNames to release unmanaged memory after native constructor copies scheme names

Related Issues

Closes #224
Closes #226
Closes #223
Closes #231
Closes #232
Closes #151
Closes #182

Checklist

• My code follows InfiniFrame's coding conventions
• I added comments for complex or non-obvious code
• Documentation updated (if applicable)
• Existing tests pass
• No new warnings or errors introduced
• PR only includes changes relevant to the issue / feature

Additional Context

#224 - C API String Ownership Violation

• Problem: GetUserAgent, GetTitle, GetIconFileName returned borrowed c_str() pointers but documentation stated callers must free them
• Impact: Calling InfiniFrame_FreeString on these pointers caused undefined behavior and crashes
• Fix: Implemented platform-specific AllocateStringCopy helper and changed all three getters to return heap-allocated copies

#223 - bool/BOOL Type Mismatch (Memory Corruption)

• Problem: bool* (1 byte) cast to BOOL* (4 bytes) in WebView2 API calls caused stack corruption
• Impact: WebView2 wrote 4 bytes into 1-byte storage, corrupting adjacent stack memory
• Fix: Use intermediate BOOL variable and safe conversion: *enabled = (boolValue != FALSE)

#226 - Null Pointer Dereference in WM_ACTIVATE

• Problem: WM_ACTIVATE handler dereferenced hwndToInfiniFrame[hwnd] without null-check
• Impact: Crash when message arrives before map insertion or after removal
• Fix: Added null-guard consistent with other message handlers (WM_CLOSE, WM_DESTROY, etc.)

#151 - Null Function Pointer in Dark Mode

• Problem: IsColorSchemeChange unconditionally called RefreshImmersiveColorPolicyState and GetIsImmersiveColorUsingHighContrast
• Impact: Crash on Windows < build 18362 or when uxtheme.dll load fails
• Fix: Added null-checks before calling function pointers

#232 - EventSubscription Token 0 Bug

• Problem: Token sequence started at 0, but Unsubscribe/IsActive checked m_token != 0
• Impact: First subscription never unsubscribed, causing stale handlers
• Fix: Changed m_nextToken initial value from 0 to 1

#231 - Platform-Specific CMake Variables

• Problem: Linux build used CMAKE_OSX_ARCHITECTURES (macOS-only variable)
• Impact: Misleading configuration, incorrect cross-compilation setup
• Fix: Moved CMAKE_OSX_ARCHITECTURES to macOS section, Linux uses default detection

#182 - CustomSchemeNames Memory Leak

• Problem: Memory allocated via Marshal.StringToHGlobalAnsi never freed
• Impact: Unmanaged memory leak when creating/destroying windows with custom schemes
• Fix: Added FreeCustomSchemeNames helper called after native constructor (which copies the strings)

Testing Notes

These fixes address memory safety issues that may not be caught by existing tests

[AnnaSasDev]

D:\a\InfiniFrame\InfiniFrame\tests\InfiniFrameTests.Playwright\bin\Release\net8.0\InfiniFrameTests.Playwright.dll (net8.0|x64) Zero tests ran (7s 167ms)
Exit code: -1073741819
  Error output: Fatal error. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
  Repeat 2 times:
  --------------------------------
     at InfiniFrame.Native.InfiniFrameNative.<SendWebMessage>g____PInvoke|60_0(IntPtr, Byte*)
  --------------------------------
     at InfiniFrame.Native.InfiniFrameNative.SendWebMessage(IntPtr, System.String)
     at InfiniFrame.InfiniFrameWindow+<>c__DisplayClass147_0.<SendWebMessage>b__0()
     at InfiniFrame.Native.InfiniFrameNative.<WaitForExit>g____PInvoke|62_0(IntPtr)
     at InfiniFrame.Native.InfiniFrameNative.<WaitForExit>g____PInvoke|62_0(IntPtr)
     at InfiniFrame.Native.InfiniFrameNative.WaitForExit(IntPtr)
     at InfiniFrame.InfiniFrameWindow.<WaitForClose>b__144_0()
     at InfiniFrame.InfiniFrameWindow.Invoke(System.Action)
     at InfiniFrame.InfiniFrameWindow.WaitForClose()
     at InfiniFrameTests.Shared.InfiniFrameServerTestUtility+<>c__DisplayClass11_0.<Create>b__0()
     at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)

Seens to be that something went wrong with dotnet 8 and dotnet 9 Playwright

[freakdaniel]

@AnnaSasDev This problem appeared not bcs of me. I launched tests before the last merge from InfiniFrame upstream:
First one: https://github.com/freakdaniel/InfiniFrame/actions/runs/24452559864
And after macOS variable fix: https://github.com/freakdaniel/InfiniFrame/actions/runs/24453028634

So the problem comes with your commit here: bde0e05

[freakdaniel]

Fixed with double-check in invoke. All tests passed: https://github.com/freakdaniel/InfiniFrame/actions/runs/24456388737