fix: respect core.bare=true in conjunction with the main worktree (#1683)

Author: Byron

gix/src/open/repository.rs

@@ -303,15 +303,33 @@ impl ThreadSafeRepository {
             }
         }
 
-        match worktree_dir {
-            None if !config.is_bare && refs.git_dir().file_name() == Some(OsStr::new(gix_discover::DOT_GIT_DIR)) => {
-                worktree_dir = Some(git_dir.parent().expect("parent is always available").to_owned());
-            }
-            Some(_) => {
-                // note that we might be bare even with a worktree directory - work trees don't have to be
-                // the parent of a non-bare repository.
+        {
+            let looks_like_standard_git_dir =
+                || refs.git_dir().file_name() == Some(OsStr::new(gix_discover::DOT_GIT_DIR));
+            match worktree_dir {
+                None if !config.is_bare && looks_like_standard_git_dir() => {
+                    worktree_dir = Some(git_dir.parent().expect("parent is always available").to_owned());
+                }
+                Some(_) => {
+                    // We may assume that the presence of a worktree-dir means it's not bare, but only if there
+                    // is no configuration saying otherwise.
+                    // Thus, if we are here and the common-dir config claims it's bare and we have inferred a worktree anyway,
+                    // forget about it.
+                    if looks_like_standard_git_dir()
+                        && config
+                            .resolved
+                            .boolean_filter("core.bare", |md| md.source == gix_config::Source::Local)
+                            .transpose()
+                            .ok()
+                            .flatten()
+                            .is_some()
+                        && config.is_bare
+                    {
+                        worktree_dir = None;
+                    }
+                }
+                None => {}
             }
-            None => {}
         }
 
         refs.write_reflog = config::cache::util::reflog_or_default(config.reflog, worktree_dir.is_some());

gix/tests/fixtures/make_worktree_repo.sh

@@ -56,3 +56,11 @@ mkdir $worktree && touch $worktree/file
   git add file
   git commit -m "make sure na index exists"
 )
+
+git init non-bare-turned-bare
+(cd non-bare-turned-bare
+  git commit --allow-empty -m 'empty'
+  git config core.bare true
+
+  git worktree add ../worktree-of-bare-repo
+)

gix/tests/gix/repository/open.rs

@@ -66,6 +66,37 @@ fn bare_repo_with_index() -> crate::Result {
     Ok(())
 }
 
+#[test]
+fn non_bare_turned_bare() -> crate::Result {
+    let repo = named_subrepo_opts(
+        "make_worktree_repo.sh",
+        "non-bare-turned-bare",
+        gix::open::Options::isolated(),
+    )?;
+    assert!(
+        repo.is_bare(),
+        "the configuration dictates this, even though it looks like a main worktree"
+    );
+    assert_eq!(repo.work_dir(), None);
+    Ok(())
+}
+
+#[test]
+fn worktree_of_bare_repo() -> crate::Result {
+    let repo = named_subrepo_opts(
+        "make_worktree_repo.sh",
+        "worktree-of-bare-repo",
+        gix::open::Options::isolated(),
+    )?;
+    assert!(!repo.is_bare(), "even though the main worktree is bare, this isn't");
+    assert_ne!(
+        repo.work_dir(),
+        None,
+        "we have opened the repo through a worktree, which is never bare"
+    );
+    Ok(())
+}
+
 #[test]
 fn non_bare_non_git_repo_without_worktree() -> crate::Result {
     let repo = named_subrepo_opts(
@@ -182,12 +213,12 @@ mod missing_config_file {
             "worktree-no-config",
             gix::open::Options::isolated(),
         )?;
-        assert!(repo.work_dir().is_some());
-        assert!(repo.worktree().is_some());
         assert!(
             !repo.is_bare(),
             "without config, we can't really know what the repo is actually but can guess as there is a worktree"
         );
+        assert!(repo.work_dir().is_some());
+        assert!(repo.worktree().is_some());
         assert_eq!(
             repo.config_snapshot().meta().source,
             gix::config::Source::Local,