# PDF merge regression checks

Run with the .NET 8 SDK:

```sh
dotnet run --project tests/PdfMergeRegression
```

This console harness links the production merge class and uses the same iText
7.1.13 dependency, without loading WPF. It checks page order, single-file copies,
source-path protection, failed merges, replacement, and temporary-file cleanup.
It does not change the application's .NET Core 3.1 target.

Also check the WPF application on Windows: after an invalid or inaccessible PDF,
the error must leave the selection and destination intact, without a success
message; after a successful merge, both fields should clear. Check uppercase
`.PDF` destinations and the single-input case as well.