workon/
fetch.rs

1//! Prune-fetch helpers for keeping remote-tracking refs in sync.
2//!
3//! "Gone" upstream detection in `prune --gone` relies on `Branch::upstream()` returning
4//! `Err` for a branch whose tracking ref was deleted on the remote. That only happens
5//! after a *prune-fetch* — a fetch that also removes stale `refs/remotes/<remote>/*`
6//! entries. Nothing in the codebase performed such a fetch before this module.
7//!
8//! Two public functions are provided:
9//!
10//! - [`remotes_tracked_by_worktrees`] — discover which remotes are relevant (deduplicated
11//!   list of `branch.<name>.remote` values across all worktrees).
12//! - [`prune_fetch`] — run the equivalent of `git fetch --prune <remote>` for a single
13//!   remote, deleting stale remote-tracking refs and then fetching.
14
15use git2::{FetchOptions, FetchPrune};
16
17use crate::error::Result;
18use crate::get_remote_callbacks::get_remote_callbacks;
19use crate::worktree::WorktreeDescriptor;
20
21/// Returns the deduplicated list of remote names tracked by the given worktrees.
22///
23/// For each worktree with a local branch that has an upstream configured, reads
24/// `branch.<name>.remote` from git config. Results are deduplicated and returned in
25/// stable (first-seen) order. Worktrees with detached HEAD or no upstream are
26/// silently skipped.
27pub fn remotes_tracked_by_worktrees(
28    repo: &git2::Repository,
29    worktrees: &[WorktreeDescriptor],
30) -> Result<Vec<String>> {
31    let config = repo.config()?;
32    let mut remotes: Vec<String> = Vec::new();
33
34    for wt in worktrees {
35        let branch_name = match wt.branch()? {
36            Some(name) => name,
37            None => continue, // detached HEAD
38        };
39
40        let remote_key = format!("branch.{}.remote", branch_name);
41        if let Ok(remote) = config.get_string(&remote_key) {
42            if !remotes.contains(&remote) {
43                remotes.push(remote);
44            }
45        }
46    }
47
48    Ok(remotes)
49}
50
51/// Prune-fetch from a single remote: remove stale remote-tracking refs, then fetch.
52///
53/// Equivalent to `git fetch --prune <remote>`. After this call, any
54/// `refs/remotes/<remote>/<branch>` ref that no longer exists on the remote is
55/// deleted locally, making `Branch::upstream()` correctly return `Err` (i.e. "gone")
56/// for branches that were deleted upstream.
57///
58/// Returns `Err` on auth failure, network error, or unknown remote. Callers that
59/// want warn-and-continue behaviour should catch the error and proceed without
60/// aborting the rest of the prune.
61pub fn prune_fetch(repo: &git2::Repository, remote_name: &str) -> Result<()> {
62    let mut remote = repo.find_remote(remote_name)?;
63
64    // Stash the URL before we borrow remote mutably.
65    // url() returns Result<&str, _> in this git2 version; ignore errors (URL may be absent).
66    let remote_url = remote.url().ok().map(str::to_owned);
67    let auth = get_remote_callbacks(repo, remote_url.as_deref())?;
68
69    let mut fetch_opts = FetchOptions::new();
70    fetch_opts.prune(FetchPrune::On); // equivalent to --prune: delete stale tracking refs
71    fetch_opts.remote_callbacks(auth.callbacks());
72
73    // Empty refspec slice = use the remote's configured refspecs (same as `git fetch origin`).
74    remote.fetch(&[] as &[&str], Some(&mut fetch_opts), None)?;
75
76    Ok(())
77}
workon/fetch.rs

workon/
fetch.rs
