Turn attribute files into a Cow to support other usecases… (#301)

…but it feels a little like a hack. Maybe this should tell us that
we need to reorganize code elsewhere?

Author: Byron

git-worktree/src/fs/cache/state.rs

@@ -3,6 +3,7 @@ use crate::fs::PathOidMapping;
 use bstr::{BStr, BString, ByteSlice};
 use git_glob::pattern::Case;
 use git_hash::oid;
+use std::borrow::Cow;
 use std::path::Path;
 
 type AttributeMatchGroup = git_attributes::MatchGroup<git_attributes::Attributes>;
@@ -150,7 +151,7 @@ impl Ignore {
         let ignore_path_relative = rela_dir.join(".gitignore");
         let ignore_path_relative = git_path::to_unix_separators_on_windows(git_path::into_bstr(ignore_path_relative));
         let ignore_file_in_index =
-            attribute_files_in_index.binary_search_by(|t| t.0.cmp(ignore_path_relative.as_ref()));
+            attribute_files_in_index.binary_search_by(|t| t.0.as_ref().cmp(ignore_path_relative.as_ref()));
         let follow_symlinks = ignore_file_in_index.is_err();
         if !self
             .stack
@@ -267,7 +268,7 @@ impl State {
                     if is_ignore && !entry.flags.contains(git_index::entry::Flags::SKIP_WORKTREE) {
                         return None;
                     }
-                    Some((path, entry.id))
+                    Some((Cow::Borrowed(path), entry.id))
                 } else {
                     None
                 }

git-worktree/src/fs/mod.rs

@@ -1,4 +1,5 @@
 use bstr::BStr;
+use std::borrow::Cow;
 use std::path::PathBuf;
 
 /// Common knowledge about the worktree that is needed across most interactions with the work tree
@@ -69,7 +70,7 @@ pub struct Cache<'paths> {
     attribute_files_in_index: Vec<PathOidMapping<'paths>>,
 }
 
-pub(crate) type PathOidMapping<'paths> = (&'paths BStr, git_hash::ObjectId);
+pub(crate) type PathOidMapping<'paths> = (Cow<'paths, BStr>, git_hash::ObjectId);
 
 ///
 pub mod cache;

git-worktree/tests/worktree/fs/cache.rs

@@ -118,6 +118,7 @@ mod create_directory {
 #[allow(unused)]
 mod ignore_and_attributes {
     use bstr::{BStr, ByteSlice};
+    use std::borrow::Cow;
     use std::path::Path;
 
     use git_glob::pattern::Case;
@@ -180,7 +181,7 @@ mod ignore_and_attributes {
         assert_eq!(
             attribute_files_in_index,
             vec![(
-                "other-dir-with-ignore/.gitignore".as_bytes().as_bstr(),
+                Cow::Borrowed("other-dir-with-ignore/.gitignore".as_bytes().as_bstr()),
                 hex_to_id("5c7e0ed672d3d31d83a3df61f13cc8f7b22d5bfd")
             )]
         );