26.5.1

26.5.1 — Image-area redaction now works on Linux & macOS

What changed

• Fixed redact_image_area on Linux/macOS (including the Docker image). Added
  GdiPlusResolver (registered from Program.cs at startup) that maps the
  gdiplus.dll P/Invoke — emitted by System.Drawing.Common's GDI+ interop, which
  GroupDocs.Redaction reaches through Aspose.Pdf — to the platform's libgdiplus
  (libgdiplus.so / libgdiplus.dylib). It's a no-op on Windows (built-in GDI+).
• Engine (GroupDocs.Redaction) stays at 26.5.0; only the MCP package version is bumped.

Why

On non-Windows, the .NET native-library loader probes gdiplus.dll,
libgdiplus.dll, and the .so/.dylib variants of those names — but never the
installed libgdiplus.so / libgdiplus.dylib. So redact_image_area threw
System.DllNotFoundException: Unable to load shared library 'gdiplus.dll' on Linux
and macOS even when libgdiplus was installed (apt libgdiplus / brew
mono-libgdiplus), and inside the Docker image. The resolver intercepts that load
and redirects it to the real libgdiplus. The other four tools never touched this
path and were unaffected.

This surfaced via the integration suite: RedactImageAreaTests failed on the
ubuntu and macOS CI legs (Windows passed — GDI+ is built in).

Migration / impact

• libgdiplus must still be present on the host: the Docker image installs it; native
  (dnx / global tool) users install it per the README
  (apt-get install libgdiplus / brew install mono-libgdiplus). The resolver only
  fixes the name mapping, not a missing library.
• No API or tool-surface change. GdiPlusResolver must run before the first GDI+
  P/Invoke — do not remove the GdiPlusResolver.Register(); call at the top of
  Program.cs.

Full Changelog: 26.5.0...26.5.1