feat!: report findings with exit code 4, not the code for failure

src/commands/link/check.rs

@@ -1,6 +1,5 @@
 use fs_err::{read_dir, read_link};
 use std::path::{Path, PathBuf};
-use std::process::ExitCode;
 
 use anyhow::{Result, anyhow};
 
@@ -9,14 +8,14 @@ use crate::cmd::{Cmd, LsFiles};
 use crate::ctx::Ctx;
 use crate::output::{line, text};
 
+// whether anything is outside the store, which main turns into an exit code
 pub fn check(
     ctx: &Ctx,
     paths: &[PathBuf],
     porcelain: bool,
     null: bool,
-    exit_code: bool,
     store: Option<&Path>,
-) -> Result<ExitCode> {
+) -> Result<bool> {
     let repo = Repo::discover(ctx, store)?;
     let pathspecs = relative_pathspecs(&repo, paths)?;
 
@@ -43,19 +42,12 @@ pub fn check(
         print_listing(&repo, &exposed);
     }
 
-    // git's --exit-code convention: nothing to report is 0, anything is 1
-    if exit_code && !exposed.is_empty() {
-        return Ok(ExitCode::FAILURE);
-    }
-
-    Ok(ExitCode::SUCCESS)
+    Ok(!exposed.is_empty())
 }
 
 fn print_porcelain(exposed: &[Exposed], null: bool) {
     let end = if null { '\0' } else { '\n' };
-    // a filename can hold an arrow but not a NUL, so -z separates the two paths
-    // with one the way `git status -z` does for a rename. the two character code
-    // stays where it is: it cannot be mistaken for part of a path
+    // a filename can hold an arrow but not a NUL, as `git status -z` also assumes
     let between = if null { "\0" } else { " -> " };
 
     for item in exposed {