fix!: assure fifo or non-files aren't considered files, but are pruned instead.

That way, algorithms relying on dirwalking can still see them if they want to,
but would have a hard time to use them (accidentally).

Note that this replaces the `From` implementation with `entry::Kind::try_from_file_type()`,
which makes this a breaking change.`

Author: Byron

gix-dir/src/entry.rs

@@ -147,15 +147,20 @@ impl Entry {
     }
 }
 
-impl From<std::fs::FileType> for Kind {
-    fn from(value: std::fs::FileType) -> Self {
-        if value.is_dir() {
+impl Kind {
+    /// Try to represent the file type `t` as `Entry`, or return `None` if it cannot be represented.
+    ///
+    /// The latter can happen if it's a `pipe` for instance.
+    pub fn try_from_file_type(t: std::fs::FileType) -> Option<Self> {
+        Some(if t.is_dir() {
             Kind::Directory
-        } else if value.is_symlink() {
+        } else if t.is_symlink() {
             Kind::Symlink
-        } else {
+        } else if t.is_file() {
             Kind::File
-        }
+        } else {
+            return None;
+        })
     }
 }
 

gix-dir/src/walk/classify.rs

@@ -20,7 +20,10 @@ pub fn root(
     let mut last_length = None;
     let mut path_buf = worktree_root.to_owned();
     // These initial values kick in if worktree_relative_root.is_empty();
-    let file_kind = path_buf.symlink_metadata().map(|m| m.file_type().into()).ok();
+    let file_kind = path_buf
+        .symlink_metadata()
+        .ok()
+        .and_then(|m| entry::Kind::try_from_file_type(m.file_type()));
     let mut out = path(&mut path_buf, buf, 0, file_kind, || None, options, ctx)?;
     let worktree_root_is_repository = out
         .disk_kind
@@ -32,7 +35,10 @@ pub fn root(
         }
         path_buf.push(component);
         buf.extend_from_slice(gix_path::os_str_into_bstr(component.as_os_str()).expect("no illformed UTF8"));
-        let file_kind = path_buf.symlink_metadata().map(|m| m.file_type().into()).ok();
+        let file_kind = path_buf
+            .symlink_metadata()
+            .ok()
+            .and_then(|m| entry::Kind::try_from_file_type(m.file_type()));
 
         out = path(
             &mut path_buf,
@@ -122,6 +128,8 @@ impl<'a> EntryRef<'a> {
 ///
 /// Returns `(status, file_kind, pathspec_matches_how)` to identify the `status` on disk, along with a classification `file_kind`,
 /// and if `file_kind` is not a directory, the way the pathspec matched with `pathspec_matches_how`.
+///
+/// Note that non-files are pruned by default.
 pub fn path(
     path: &mut PathBuf,
     rela_path: &mut BString,

gix-dir/src/walk/readdir.rs

@@ -64,7 +64,7 @@ pub(super) fn recursive(
             current_bstr,
             if prev_len == 0 { 0 } else { prev_len + 1 },
             None,
-            || entry.file_type().ok().map(Into::into),
+            || entry.file_type().ok().and_then(entry::Kind::try_from_file_type),
             opts,
             ctx,
         )?;

gix-dir/tests/dir/walk.rs

@@ -97,12 +97,12 @@ fn fifo_in_traversal() {
     assert_eq!(
         entries,
         &[
+            entry_nokind(".git", Pruned).with_property(DotGit).with_match(Always),
             entry("dir-with-file/nested-file", Untracked, File),
-            entry_nokind("dir/nested", Pruned),
             entry("file", Untracked, File),
-            entry_nokind("top", Untracked),
         ],
-        "Non-files are simply pruned, and don't have a disk kind"
+        "Non-files are not even pruned, they are ignored entirely.\
+        If one day this isn't what we want, we can create an own filetype for them"
     );
 }