fix!: Add entry::Kind::NonFile.

Previously, these were misclassified as `File`, which can lead to blocking applications
which get stuck reading pipes.

Now the downstream is forced to deal with the possibility that the item at hand isn't a file,
to do application-specific things.

Author: Byron

gix-dir/src/entry.rs

@@ -1,6 +1,7 @@
 use crate::walk::ForDeletionMode;
 use crate::{Entry, EntryRef};
 use std::borrow::Cow;
+use std::fs::FileType;
 
 /// A way of attaching additional information to an [Entry] .
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
@@ -25,6 +26,10 @@ pub enum Property {
 /// The kind of the entry, seated in their kinds available on disk.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub enum Kind {
+    /// Something that is not a file, like a named pipe or character device.
+    ///
+    /// These can only exist in the filesystem.
+    NonFile,
     /// The entry is a blob, executable or not.
     File,
     /// The entry is a symlink.
@@ -147,20 +152,17 @@ impl Entry {
     }
 }
 
-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() {
+impl From<std::fs::FileType> for Kind {
+    fn from(value: FileType) -> Self {
+        if value.is_dir() {
             Kind::Directory
-        } else if t.is_symlink() {
+        } else if value.is_symlink() {
             Kind::Symlink
-        } else if t.is_file() {
+        } else if value.is_file() {
             Kind::File
         } else {
-            return None;
-        })
+            Kind::NonFile
+        }
     }
 }
 

gix-dir/src/walk/classify.rs

@@ -20,10 +20,7 @@ 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()
-        .ok()
-        .and_then(|m| entry::Kind::try_from_file_type(m.file_type()));
+    let file_kind = path_buf.symlink_metadata().ok().map(|m| m.file_type().into());
     let mut out = path(&mut path_buf, buf, 0, file_kind, || None, options, ctx)?;
     let worktree_root_is_repository = out
         .disk_kind
@@ -35,10 +32,7 @@ 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()
-            .ok()
-            .and_then(|m| entry::Kind::try_from_file_type(m.file_type()));
+        let file_kind = path_buf.symlink_metadata().ok().map(|m| m.file_type().into());
 
         out = path(
             &mut path_buf,

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().and_then(entry::Kind::try_from_file_type),
+            || entry.file_type().ok().map(Into::into),
             opts,
             ctx,
         )?;

gix-dir/tests/dir/walk.rs

@@ -66,7 +66,11 @@ fn one_top_level_fifo() {
         }
     );
 
-    assert_eq!(entries, &[], "Non-files are simply pruned by default");
+    assert_eq!(
+        entries,
+        &[entry("top", Untracked, NonFile),],
+        "Non-files are like normal files, but with a different state"
+    );
 }
 
 #[test]
@@ -99,10 +103,11 @@ fn fifo_in_traversal() {
         &[
             entry_nokind(".git", Pruned).with_property(DotGit).with_match(Always),
             entry("dir-with-file/nested-file", Untracked, File),
+            entry("dir/nested", Untracked, NonFile),
             entry("file", Untracked, File),
+            entry("top", Untracked, NonFile),
         ],
-        "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"
+        "Non-files only differ by their disk-kind"
     );
 }