emacs: tramp: detect wrapped gvfsd-fuse daemon

[liff]

Motivation for this change

Tramp checks for a running gvfsd-fuse process to figure out whether to enable gvfs-based. Its tramp-compat-process-running-p function uses /proc/<pid>/comm to check for the name of running process(es). In Nix, the gvfsd processes are launched via wrappers and the name of gvfsd-fuse in
comm in Linux is .gvfsd-fuse-wra (truncated to 15 characters) which means the process is not detected and tramp-gvfs-enabled ends up with nil even when gvfs is available.

This patch adds .gvfsd-fuse-wrapped to the list of process names to check when determining the value of tramp-gvfs-enabled.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

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[Mic92]

Would it help if we wrap gvfsd-fuse with --argv0 to gvfsd-fuse set when calling makeWrapper?

[liff]

Oh, I’ll try that out. Thanks.

[liff]

@Mic92 the wrapper already sets --argv0 (via wrapGAppsHook -> wrapProgram).

However, even if it didn’t it wouldn’t help because Tramp is specifically looking at the comm attribute, which comes from /proc/<pid>/comm which, as far as I can tell, could only be changed by the program that was execed.