various improvements

gix-index/src/entry/mode.rs

@@ -49,6 +49,7 @@ impl Mode {
     ) -> Option<Change> {
         match self {
             Mode::FILE if !stat.is_file() => (),
+            Mode::SYMLINK if stat.is_symlink() => return None,
             Mode::SYMLINK if has_symlinks && !stat.is_symlink() => (),
             Mode::SYMLINK if !has_symlinks && !stat.is_file() => (),
             Mode::COMMIT | Mode::DIR if !stat.is_dir() => (),

gix-ref/src/store/file/mod.rs

@@ -53,7 +53,7 @@ mod access {
         }
     }
 
-    use crate::file;
+    use crate::{file, Target};
 
     /// Access
     impl file::Store {
@@ -78,6 +78,35 @@ mod access {
         pub fn common_dir_resolved(&self) -> &Path {
             self.common_dir.as_deref().unwrap_or(&self.git_dir)
         }
+
+        /// Return `Some(true)` if this is a freshly initialized ref store without any observable changes.
+        /// Return `None` if `HEAD` couldn't be read.
+        ///
+        /// This is the case if:
+        ///
+        /// * the ref-store is valid
+        /// * `HEAD` exists
+        /// * `HEAD` still points to `default_ref`
+        /// * there are no packed refs
+        /// * There are no observable references in `refs/`
+        pub fn is_pristine(&self, default_ref: &crate::FullNameRef) -> Option<bool> {
+            let head = self.find_loose("HEAD").ok()?;
+            match head.target {
+                Target::Object(_) => return Some(false),
+                Target::Symbolic(name) => {
+                    if name.as_ref() != default_ref {
+                        return Some(false);
+                    }
+                }
+            }
+            if self.loose_iter().ok()?.filter_map(Result::ok).next().is_some() {
+                return Some(false);
+            }
+            if self.packed_refs_path().is_file() {
+                return Some(false);
+            }
+            Some(true)
+        }
     }
 }
 

gix-ref/tests/fixtures/make_pristine.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+set -eu -o pipefail
+
+git init untouched
+
+git init changed-headref
+(cd changed-headref
+  echo "ref: refs/heads/other" >.git/HEAD
+)
+
+git init detached
+(cd detached
+  echo "abcdefabcdefabcdefabcdefabcdefabcdefabcd" >.git/HEAD
+)
+
+git init invalid-loose-ref
+(cd invalid-loose-ref
+  touch .git/refs/heads/empty
+)

gix-ref/tests/refs/file/mod.rs

@@ -14,8 +14,12 @@ pub fn store_with_packed_refs() -> crate::Result<Store> {
 }
 
 pub fn store_at(name: &str) -> crate::Result<Store> {
-    let path = gix_testtools::scripted_fixture_read_only_standalone(name)?;
-    Ok(Store::at(path.join(".git"), Default::default()))
+    named_store_at(name, "")
+}
+
+pub fn named_store_at(script_name: &str, name: &str) -> crate::Result<Store> {
+    let path = gix_testtools::scripted_fixture_read_only_standalone(script_name)?;
+    Ok(Store::at(path.join(name).join(".git"), Default::default()))
 }
 
 pub fn store_at_with_args(name: &str, args: impl IntoIterator<Item = impl Into<String>>) -> crate::Result<Store> {

gix-ref/tests/refs/file/store/access.rs

@@ -1,4 +1,4 @@
-use crate::file::store;
+use crate::file::{named_store_at, store};
 
 #[test]
 fn set_packed_buffer_mmap_threshold() -> crate::Result {
@@ -20,3 +20,22 @@ fn set_packed_buffer_mmap_threshold() -> crate::Result {
     );
     Ok(())
 }
+
+#[test]
+fn is_pristine() -> crate::Result {
+    let store = named_store_at("make_pristine.sh", "untouched")?;
+    assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(true));
+    assert_eq!(store.is_pristine("refs/heads/other".try_into()?), Some(false));
+
+    let store = named_store_at("make_pristine.sh", "changed-headref")?;
+    assert_eq!(store.is_pristine("refs/heads/other".try_into()?), Some(true));
+    assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(false));
+
+    let store = named_store_at("make_pristine.sh", "detached")?;
+    assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(false));
+
+    let store = named_store_at("make_pristine.sh", "invalid-loose-ref")?;
+    assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(true));
+
+    Ok(())
+}

gix-ref/tests/refs/file/store/find.rs

@@ -9,6 +9,7 @@ mod existing {
             "make_packed_ref_repository_for_overlay.sh",
         ] {
             let store = store_at(fixture)?;
+            assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(false));
             let c1 = hex_to_id("134385f6d781b7e97062102c6a483440bfda2a03");
             let r = store.find("main")?;
             assert_eq!(r.target.into_id(), c1);

gix-ref/tests/refs/file/store/iter.rs

@@ -576,6 +576,7 @@ fn overlay_partial_prefix_iter_when_prefix_is_dir() -> crate::Result {
     use gix_ref::Target::*;
 
     let store = store_at("make_packed_ref_repository_for_overlay.sh")?;
+    assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(false));
     let c1 = hex_to_id("134385f6d781b7e97062102c6a483440bfda2a03");
 
     let ref_names = store

gix-ref/tests/refs/file/worktree.rs

@@ -84,6 +84,7 @@ mod read_only {
     fn linked() -> crate::Result {
         for packed in [false, true] {
             let (store, odb, _tmp) = worktree_store(packed, "w1", Mode::Read)?;
+            assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(false));
             let peel = into_peel(&store, odb);
 
             let w1_head_id = peel(store.find("HEAD").unwrap());
@@ -132,6 +133,7 @@ mod read_only {
     fn main() -> crate::Result {
         for packed in [false, true] {
             let (store, odb, _tmp) = main_store(packed, Mode::Read)?;
+            assert_eq!(store.is_pristine("refs/heads/main".try_into()?), Some(false));
             let peel = into_peel(&store, odb);
 
             let head_id = peel(store.find("HEAD").unwrap());

gix-status/src/index_as_worktree/function.rs

@@ -408,12 +408,12 @@ impl<'index> State<'_, 'index> {
                 None => false,
             };
 
-        // Here we implement racy-git. See racy-git.txt in the git documentation for a detailed documentation.
+        // We implement racy-git. See racy-git.txt in the git documentation for detailed documentation.
         //
         // A file is racy if:
-        // 1. its `mtime` is at or after the last index timestamp and its entry stat information
-        //   matches the on-disk file but the file contents are actually modified
-        // 2. it's size is 0 (set after detecting a file was racy previously)
+        // 1. Its `mtime` is at or after the last index timestamp and its entry stat information
+        //   matches the on-disk file, but the file contents are actually modified
+        // 2. Its size is 0 (set after detecting a file was racy previously)
         //
         // The first case is detected below by checking the timestamp if the file is marked unmodified.
         // The second case is usually detected either because the on-disk file is not empty, hence
@@ -449,7 +449,16 @@ impl<'index> State<'_, 'index> {
             file_len: file_size_bytes,
             filter: &mut self.filter,
             attr_stack: &mut self.attr_stack,
-            options: self.options,
+            core_symlinks:
+            // If this is legitimately a symlink, then pretend symlinks are enabled as the option seems stale.
+            // Otherwise, respect the option.
+            if metadata.is_symlink()
+                && entry.mode.to_tree_entry_mode().map(|m| m.kind()) == Some(gix_object::tree::EntryKind::Link)
+            {
+                true
+            } else {
+                self.options.fs.symlink
+            },
             id: &entry.id,
             objects,
             worktree_reads: self.worktree_reads,
@@ -517,7 +526,7 @@ where
     entry: &'a gix_index::Entry,
     filter: &'a mut gix_filter::Pipeline,
     attr_stack: &'a mut gix_worktree::Stack,
-    options: &'a Options,
+    core_symlinks: bool,
     id: &'a gix_hash::oid,
     objects: Find,
     worktree_bytes: &'a AtomicU64,
@@ -545,7 +554,7 @@ where
         //
         let is_symlink = self.entry.mode == gix_index::entry::Mode::SYMLINK;
         // TODO: what to do about precompose unicode and ignore_case for symlinks
-        let out = if is_symlink && self.options.fs.symlink {
+        let out = if is_symlink && self.core_symlinks {
             // conversion to bstr can never fail because symlinks are only used
             // on unix (by git) so no reason to use the try version here
             let symlink_path =

gix-status/tests/status/index_as_worktree.rs

@@ -48,6 +48,7 @@ fn nonfile_fixture(name: &str, expected_status: &[Expectation<'_>]) -> Outcome {
         false,
         Default::default(),
         false,
+        None,
     )
 }
 
@@ -65,6 +66,7 @@ fn fixture_with_index(
         false,
         Default::default(),
         false,
+        None,
     )
 }
 
@@ -78,6 +80,7 @@ fn submodule_fixture(name: &str, expected_status: &[Expectation<'_>]) -> Outcome
         false,
         Default::default(),
         false,
+        None,
     )
 }
 
@@ -91,6 +94,7 @@ fn conflict_fixture(name: &str, expected_status: &[Expectation<'_>]) -> Outcome
         false,
         Default::default(),
         false,
+        None,
     )
 }
 
@@ -104,6 +108,7 @@ fn submodule_fixture_status(name: &str, expected_status: &[Expectation<'_>], sub
         submodule_dirty,
         Default::default(),
         false,
+        None,
     )
 }
 
@@ -117,6 +122,7 @@ fn fixture_filtered(name: &str, pathspecs: &[&str], expected_status: &[Expectati
         false,
         Default::default(),
         false,
+        None,
     )
 }
 
@@ -130,6 +136,7 @@ fn fixture_filtered_detailed(
     submodule_dirty: bool,
     auto_crlf: gix_filter::eol::AutoCrlf,
     use_odb: bool,
+    fs_capabilities: Option<&dyn Fn(&std::path::Path) -> gix_fs::Capabilities>,
 ) -> Outcome {
     // This can easily happen in some fixtures, which can cause flakiness. It's time-dependent after all.
     fn ignore_racyclean(mut out: Outcome) -> Outcome {
@@ -179,7 +186,7 @@ fn fixture_filtered_detailed(
         should_interrupt: &AtomicBool::default(),
     };
     let options = Options {
-        fs: gix_fs::Capabilities::probe(&git_dir),
+        fs: fs_capabilities.map_or_else(|| gix_fs::Capabilities::probe(&git_dir), |new| new(&git_dir)),
         stat: TEST_OPTIONS,
         ..Options::default()
     };
@@ -353,6 +360,7 @@ fn replace_dir_with_file() {
         false,
         Default::default(),
         false,
+        None,
     );
     assert_eq!(
         out,
@@ -560,6 +568,24 @@ fn unchanged() {
     fixture("status_unchanged", &[]);
 }
 
+#[test]
+fn unchanged_symlinks_present_but_deactivated() {
+    fixture_filtered_detailed(
+        "status_unchanged",
+        "",
+        &[],
+        &[],
+        |_| {},
+        false,
+        Default::default(),
+        false,
+        Some(&|dir| gix_fs::Capabilities {
+            symlink: false,
+            ..gix_fs::Capabilities::probe(dir)
+        }),
+    );
+}
+
 #[test]
 fn unchanged_despite_filter() {
     let actual_outcome = fixture_filtered_detailed(
@@ -571,6 +597,7 @@ fn unchanged_despite_filter() {
         false,
         AutoCrlf::Enabled,
         true, /* make ODB available */
+        None,
     );
 
     let expected_outcome = Outcome {

gix/src/repository/location.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::path::{Path, PathBuf};
 
 use gix_path::realpath::MAX_SYMLINKS;
@@ -108,4 +109,20 @@ impl crate::Repository {
             None => crate::repository::Kind::Bare,
         }
     }
+
+    /// Returns `Some(true)` if the reference database [is untouched](gix_ref::file::Store::is_pristine()).
+    /// This typically indicates that the repository is new and empty.
+    /// Return `None` if a defect in the database makes the answer uncertain.
+    #[doc(alias = "is_empty", alias = "git2")]
+    pub fn is_pristine(&self) -> Option<bool> {
+        let name = self
+            .config
+            .resolved
+            .string(crate::config::tree::Init::DEFAULT_BRANCH)
+            .unwrap_or(Cow::Borrowed("master".into()));
+        let default_branch_ref_name: gix_ref::FullName = format!("refs/heads/{name}")
+            .try_into()
+            .unwrap_or_else(|_| gix_ref::FullName::try_from("refs/heads/master").expect("known to be valid"));
+        self.refs.is_pristine(default_branch_ref_name.as_ref())
+    }
 }

gix/src/repository/submodule.rs

@@ -26,7 +26,7 @@ impl Repository {
         )?))
     }
 
-    /// Return a shared [`.gitmodules` file](crate::submodule::File) which is updated automatically if the in-memory snapshot
+    /// Return a shared [`.gitmodules` file](submodule::File) which is updated automatically if the in-memory snapshot
     /// has become stale as the underlying file on disk has changed. The snapshot based on the file on disk is shared across all
     /// clones of this repository.
     ///
@@ -54,12 +54,20 @@ impl Repository {
                 }) {
                     Some(id) => id,
                     None => match self
-                        .head_commit()?
-                        .tree()?
-                        .find_entry(submodule::MODULES_FILE)
-                        .map(|entry| entry.inner.oid)
+                        .head()?
+                        .try_peel_to_id_in_place()?
+                        .map(|id| -> Result<Option<_>, submodule::modules::Error> {
+                            Ok(id
+                                .object()?
+                                .peel_to_commit()?
+                                .tree()?
+                                .find_entry(submodule::MODULES_FILE)
+                                .map(|entry| entry.inner.oid.to_owned()))
+                        })
+                        .transpose()?
+                        .flatten()
                     {
-                        Some(id) => id.to_owned(),
+                        Some(id) => id,
                         None => return Ok(None),
                     },
                 };

gix/src/status/index_worktree.rs

@@ -226,13 +226,6 @@ mod submodule_status {
                     v
                 }
                 Ok(None) => Vec::new(),
-                Err(crate::submodule::modules::Error::FindHeadCommit(
-                    crate::reference::head_commit::Error::PeelToCommit(
-                        crate::head::peel::to_commit::Error::PeelToObject(
-                            crate::head::peel::to_object::Error::Unborn { .. },
-                        ),
-                    ),
-                )) => Vec::new(),
                 Err(err) => return Err(err),
             };
             Ok(Self {

gix/src/submodule/errors.rs

@@ -23,8 +23,12 @@ pub mod modules {
         OpenIndex(#[from] crate::worktree::open_index::Error),
         #[error("Could not find the .gitmodules file by id in the object database")]
         FindExistingBlob(#[from] crate::object::find::existing::Error),
-        #[error("Did not find commit in current HEAD to access its tree")]
-        FindHeadCommit(#[from] crate::reference::head_commit::Error),
+        #[error(transparent)]
+        FindHeadRef(#[from] crate::reference::find::existing::Error),
+        #[error(transparent)]
+        PeelHeadRef(#[from] crate::head::peel::Error),
+        #[error(transparent)]
+        PeelObjectToCommit(#[from] crate::object::peel::to_kind::Error),
         #[error(transparent)]
         TreeFromCommit(#[from] crate::object::commit::Error),
     }