lib/git.rs: inline functions used only once, rename others

I now believe that jj will need to store git-tracking refs for both local and
remote-tracking branches of the git repo for the long term. See
jj-vcs#1666 (comment)

More refactoring will likely happen when that bug is fixed.

lib/src/git.rs

@@ -64,14 +64,6 @@ fn to_git_ref_name(parsed_ref: &RefName) -> String {
     }
 }
 
-fn ref_name_to_local_branch_name(ref_name: &str) -> Option<&str> {
-    ref_name.strip_prefix("refs/heads/")
-}
-
-fn local_branch_name_to_ref_name(branch: &str) -> String {
-    format!("refs/heads/{branch}")
-}
-
 /// Checks if `git_ref` points to a Git commit object, and returns its id.
 ///
 /// If the ref points to the previously `known_target` (i.e. unchanged), this
@@ -110,18 +102,16 @@ fn resolve_git_ref_to_commit_id(
     Some(CommitId::from_bytes(git_commit.id().as_bytes()))
 }
 
-// TODO: Eventually, git-tracking branches should no longer be stored in
-// git_refs but with the other remote-tracking branches in BranchTarget. Note
-// that there are important but subtle differences in behavior for, e.g. `jj
-// branch forget`.
-pub fn git_tracking_branches(view: &View) -> impl Iterator<Item = (&str, &RefTarget)> {
+pub fn local_git_tracking_branches(view: &View) -> impl Iterator<Item = (&str, &RefTarget)> {
     view.git_refs().iter().filter_map(|(ref_name, target)| {
-        ref_name_to_local_branch_name(ref_name).map(|branch_name| (branch_name, target))
+        ref_name
+            .strip_prefix("refs/heads/")
+            .map(|branch_name| (branch_name, target))
     })
 }
 
-pub fn get_git_tracking_branch<'a>(view: &'a View, branch: &str) -> Option<&'a RefTarget> {
-    view.git_refs().get(&local_branch_name_to_ref_name(branch))
+pub fn get_local_git_tracking_branch<'a>(view: &'a View, branch: &str) -> Option<&'a RefTarget> {
+    view.git_refs().get(&format!("refs/heads/{branch}"))
 }
 
 fn prevent_gc(git_repo: &git2::Repository, id: &CommitId) -> Result<(), git2::Error> {

lib/src/revset.rs

@@ -31,7 +31,7 @@ use thiserror::Error;
 
 use crate::backend::{BackendError, BackendResult, ChangeId, CommitId, ObjectId};
 use crate::commit::Commit;
-use crate::git::get_git_tracking_branch;
+use crate::git::get_local_git_tracking_branch;
 use crate::hex_util::to_forward_hex;
 use crate::index::{HexPrefix, PrefixResolution};
 use crate::op_store::WorkspaceId;
@@ -1658,7 +1658,7 @@ fn resolve_branch(repo: &dyn Repo, symbol: &str) -> Option<Vec<CommitId>> {
         }
         // A remote with name "git" will shadow local-git tracking branches
         if remote_name == "git" {
-            if let Some(target) = get_git_tracking_branch(repo.view(), name) {
+            if let Some(target) = get_local_git_tracking_branch(repo.view(), name) {
                 return Some(target.adds());
             }
         }

src/commands/branch.rs

@@ -3,7 +3,7 @@ use std::collections::BTreeSet;
 use clap::builder::NonEmptyStringValueParser;
 use itertools::Itertools;
 use jujutsu_lib::backend::{CommitId, ObjectId};
-use jujutsu_lib::git::{self, git_tracking_branches};
+use jujutsu_lib::git::{self, local_git_tracking_branches};
 use jujutsu_lib::git_backend::GitBackend;
 use jujutsu_lib::op_store::RefTarget;
 use jujutsu_lib::repo::Repo;
@@ -364,7 +364,7 @@ fn cmd_branch_list(
     let repo = workspace_command.repo();
 
     let mut all_branches = repo.view().branches().clone();
-    for (branch_name, git_tracking_target) in git_tracking_branches(repo.view()) {
+    for (branch_name, git_tracking_target) in local_git_tracking_branches(repo.view()) {
         let branch_target = all_branches.entry(branch_name.to_owned()).or_default();
         if branch_target.remote_targets.contains_key("git") {
             // TODO(#1690): There should be a mechanism to prevent importing a