Editing file breaks hard link

[Nemowang2003]

Summary

After saving the file, the hard link would be broken.
If it is working as intended, is there an option to disable this feature?

Reproduction Steps

I tried this:

1. touch a
2. ln a b
3. hx b and insert test, and save by :x
4. cat a

I expected this to happen:
cat a outputs test.
Instead, this happened:
File a remains empty, and the hard link between a and b was broken.

Helix log

~/.cache/helix/helix.log

2024-07-23T02:10:03.063 globset [DEBUG] glob converted to regex: Glob { glob: "*/Dockerfile.*", re: "(?-u)^.*/Dockerfile\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('D'), Literal('o'), Literal('c'), Literal('k'), Literal('e'), Literal('r'), Literal('f'), Literal('i'), Literal('l'), Literal('e'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/dockerfile.*", re: "(?-u)^.*/dockerfile\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('d'), Literal('o'), Literal('c'), Literal('k'), Literal('e'), Literal('r'), Literal('f'), Literal('i'), Literal('l'), Literal('e'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/Containerfile.*", re: "(?-u)^.*/Containerfile\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('C'), Literal('o'), Literal('n'), Literal('t'), Literal('a'), Literal('i'), Literal('n'), Literal('e'), Literal('r'), Literal('f'), Literal('i'), Literal('l'), Literal('e'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/containerfile.*", re: "(?-u)^.*/containerfile\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('c'), Literal('o'), Literal('n'), Literal('t'), Literal('a'), Literal('i'), Literal('n'), Literal('e'), Literal('r'), Literal('f'), Literal('i'), Literal('l'), Literal('e'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/.*ignore", re: "(?-u)^.*/\\..*ignore$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('.'), ZeroOrMore, Literal('i'), Literal('g'), Literal('n'), Literal('o'), Literal('r'), Literal('e')]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/BUILD.*", re: "(?-u)^.*/BUILD\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('B'), Literal('U'), Literal('I'), Literal('L'), Literal('D'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/.env.*", re: "(?-u)^.*/\\.env\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('.'), Literal('e'), Literal('n'), Literal('v'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/.envrc.*", re: "(?-u)^.*/\\.envrc\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('.'), Literal('e'), Literal('n'), Literal('v'), Literal('r'), Literal('c'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/conf/*/*.{inc,conf}", re: "(?-u)^.*/conf/.*/.*\\.(?:conf|inc)$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('c'), Literal('o'), Literal('n'), Literal('f'), Literal('/'), ZeroOrMore, Literal('/'), ZeroOrMore, Literal('.'), Alternates([Tokens([Literal('c'), Literal('o'), Literal('n'), Literal('f')]), Tokens([Literal('i'), Literal('n'), Literal('c')])])]) }
2024-07-23T02:10:03.064 globset [DEBUG] glob converted to regex: Glob { glob: "*/Jenkinsfile.*", re: "(?-u)^.*/Jenkinsfile\\..*$", opts: GlobOptions { case_insensitive: false, literal_separator: false, backslash_escape: true, empty_alternates: false }, tokens: Tokens([ZeroOrMore, Literal('/'), Literal('J'), Literal('e'), Literal('n'), Literal('k'), Literal('i'), Literal('n'), Literal('s'), Literal('f'), Literal('i'), Literal('l'), Literal('e'), Literal('.'), ZeroOrMore]) }
2024-07-23T02:10:03.064 globset [DEBUG] built glob set; 1 literals, 0 basenames, 0 extensions, 0 prefixes, 127 suffixes, 9 required extensions, 10 regexes
2024-07-23T02:10:03.077 helix_view::clipboard [DEBUG] Using pbcopy+pbpaste to interact with the system clipboard
2024-07-23T02:10:03.085 helix_vcs [DEBUG] Error {
    context: "failed to open git repo",
    source: Discover(
        NoGitRepository {
            path: "/tmp",
        },
    ),
}
2024-07-23T02:10:03.085 helix_vcs [DEBUG] failed to open diff base for /tmp/b
2024-07-23T02:10:03.085 helix_vcs [DEBUG] Error {
    context: "failed to open git repo",
    source: Discover(
        NoGitRepository {
            path: "/tmp",
        },
    ),
}
2024-07-23T02:10:03.085 helix_vcs [DEBUG] failed to obtain current head name for /tmp/b
2024-07-23T02:10:03.086 helix_view::editor [DEBUG] editor status: Loaded 1 file.
2024-07-23T02:10:03.090 helix_tui::backend::crossterm [DEBUG] The keyboard enhancement protocol is supported in this terminal (checked in 1.891292ms)
2024-07-23T02:10:03.091 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:03.329 helix_term::application [DEBUG] received editor event: IdleTimer
2024-07-23T02:10:03.757 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:03.882 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:04.007 helix_term::application [DEBUG] received editor event: IdleTimer
2024-07-23T02:10:04.009 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:04.518 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:04.640 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:04.705 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:04.828 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:04.875 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:04.998 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:05.088 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:05.211 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:05.340 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 0
2024-07-23T02:10:05.341 helix_term::application [DEBUG] received editor event: IdleTimer
2024-07-23T02:10:05.380 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 1
2024-07-23T02:10:05.631 helix_term::application [DEBUG] received editor event: IdleTimer
2024-07-23T02:10:05.915 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 1
2024-07-23T02:10:06.168 helix_term::application [DEBUG] received editor event: IdleTimer
2024-07-23T02:10:06.174 helix_view::document [DEBUG] id 1 modified - last saved: 0, current: 1
2024-07-23T02:10:07.651 helix_view::document [DEBUG] submitting save of doc 'Some("/tmp/b")'
2024-07-23T02:10:07.651 helix_term::job [DEBUG] waiting on jobs...
2024-07-23T02:10:07.660 helix_lsp::file_event [DEBUG] Received file event for "/tmp/b"
2024-07-23T02:10:07.660 helix_view::document [DEBUG] doc 1 revision updated 0 -> 2
2024-07-23T02:10:07.660 helix_term::commands::typed [DEBUG] quitting...
2024-07-23T02:10:07.660 helix_view::document [DEBUG] id 1 modified - last saved: 2, current: 2
2024-07-23T02:10:07.660 helix_term::job [DEBUG] waiting on jobs...
2024-07-23T02:10:07.661 helix_term::job [DEBUG] waiting on jobs...

Platform

macOS

Terminal Emulator

iterm2 3.5.3

Installation Method

brew

Helix Version

helix 24.7 (079f544)

[kirawi]

Per Vim: https:/neovim/neovim/blob/4e5c633ed4871a948aff7338b793ac5f93484153/src/nvim/bufwrite.c#L736-L742

The current system is coded such that symbolic links work with backup files, but we should disable it when it's a hardlink in

helix/helix-view/src/document.rs

Lines 930 to 952 in 86795a9

	let backup = if path.exists() {
	let path_ = write_path.clone();
	// hacks: we use tempfile to handle the complex task of creating
	// non clobbered temporary path for us we don't want
	// the whole automatically delete path on drop thing
	// since the path doesn't exist yet, we just want
	// the path
	tokio::task::spawn_blocking(move || -> Option<PathBuf> {
	tempfile::Builder::new()
	.prefix(path_.file_name()?)
	.suffix(".bck")
	.make_in(path_.parent()?, |backup| std::fs::rename(&path_, backup))
	.ok()?
	.into_temp_path()
	.keep()
	.ok()
	})
	.await
	.ok()
	.flatten()
	} else {
	None
	};

[noktoborus]

I can add additional check to #11153
in fact, this is not the only problem with the current saving procedure, because there is also a security problem: file access rights are copied only after the file is finally written, which is not very good. Perhaps the temporary file creation function exposes private access to the temporary file, which is not obvious to me and I have not checked.

[kirawi]

I will be reading through Vim's write system in full in the near future to see what needs to be changed in Helix.

[cunha]

Encountered this last Wednesday while teaching. Created a hardlink, hx'd one file, and was going to show the students that the other file was changed too and... wut?!

I was utterly confused for several seconds... then figured out the reference counters were decreased and resorted to using vim for the example.

[kirawi]

#11340 should fix this