fix: don't be too generous when extrapolating worktree directories.

Previously it was possible that a non-bare repository that didn't have
worktree directory incorrectly claimed it had one.

Author: Byron

gix/src/open/repository.rs

@@ -1,7 +1,7 @@
 #![allow(clippy::result_large_err)]
-use std::{borrow::Cow, path::PathBuf};
-
 use gix_features::threading::OwnShared;
+use std::ffi::OsStr;
+use std::{borrow::Cow, path::PathBuf};
 
 use super::{Error, Options};
 use crate::{
@@ -86,7 +86,7 @@ impl ThreadSafeRepository {
             }
         };
 
-        // The be altered later based on `core.precomposeUnicode`.
+        // To be altered later based on `core.precomposeUnicode`.
         let cwd = gix_fs::current_dir(false)?;
         let (git_dir, worktree_dir) = gix_discover::repository::Path::from_dot_git_dir(path, kind, &cwd)
             .expect("we have sanitized path with is_git()")
@@ -284,7 +284,7 @@ impl ThreadSafeRepository {
         }
 
         match worktree_dir {
-            None if !config.is_bare => {
+            None if !config.is_bare && refs.git_dir().extension() == Some(OsStr::new(gix_discover::DOT_GIT_DIR)) => {
                 worktree_dir = Some(git_dir.parent().expect("parent is always available").to_owned());
             }
             Some(_) => {

gix/tests/fixtures/generated-archives/make_basic_repo.tar

@@ -36,4 +36,9 @@ git init all-untracked
 git init empty-core-excludes
 (cd empty-core-excludes
   echo $'[core]\n\texcludesFile = ' >> .git/config
+)
+
+git clone --bare . non-bare-without-worktree
+(cd non-bare-without-worktree
+  git config core.bare false
 )

gix/tests/fixtures/make_basic_repo.sh

@@ -42,6 +42,7 @@ mod dirwalk {
             ("bare.git".into(), Directory),
             ("empty-core-excludes".into(), Repository),
             ("non-bare-repo-without-index".into(), Repository),
+            ("non-bare-without-worktree".into(), Directory),
             ("some".into(), Directory),
         ];
         assert_eq!(

gix/tests/gix/repository/mod.rs

@@ -62,6 +62,30 @@ fn bare_repo_with_index() -> crate::Result {
         repo.is_bare(),
         "it's properly classified as it reads the configuration (and has no worktree)"
     );
+    assert_eq!(repo.work_dir(), None);
+    Ok(())
+}
+
+#[test]
+fn non_bare_non_git_repo_without_worktree() -> crate::Result {
+    let repo = named_subrepo_opts(
+        "make_basic_repo.sh",
+        "non-bare-without-worktree",
+        gix::open::Options::isolated(),
+    )?;
+    assert!(!repo.is_bare());
+    assert_eq!(repo.work_dir(), None, "it doesn't assume that workdir exists");
+
+    let repo = gix::open_opts(
+        repo.git_dir().join("objects").join(".."),
+        gix::open::Options::isolated(),
+    )?;
+    assert!(!repo.is_bare());
+    assert_eq!(
+        repo.work_dir(),
+        None,
+        "it figures this out even if a non-normalized gitdir is used"
+    );
     Ok(())
 }