bug#66211: 30.0.50; C-x v v in vc-diff does not work with lesser versionf of patch

[Dmitry Gutov]

On 26/09/2023 15:17, Alfred M. Szmidt wrote:
> The C-x v v command in a*vc-diff*  buffer does not work if you have a
> lesser version of patch, e.g., the one on OpenBSD:
>
> user-error: Patch failed: patch: unknown option -- no-backup-if-mismatch
> usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]
>               [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]
>               [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]
>               [--posix] [origfile [patchfile]]
>         patch <patchfile

Thanks for the report.

Any idea how to implement the same thing using your version of 'patch'?