refactor for checkout to use fs::Context (#301)

The latter should be useful when fully implementing all required
baseline capabilities of doing a correct checkout

git-worktree/src/fs.rs

@@ -0,0 +1,56 @@
+/// Common knowledge about the worktree that is needed across most interactions with the work tree
+#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
+#[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]
+pub struct Context {
+    /// If true, the filesystem will store paths as decomposed unicode, i.e. `ä` becomes `"a\u{308}"`, which means that
+    /// we have to turn these forms back from decomposed to precomposed unicode before storing it in the index or generally
+    /// using it. This also applies to input received from the command-line, so callers may have to be aware of this and
+    /// perform conversions accordingly.
+    /// If false, no conversions will be performed.
+    pub precompose_unicode: bool,
+    /// If true, the filesystem ignores the case of input, which makes `A` the same file as `a`.
+    /// This is also called case-folding.
+    pub ignore_case: bool,
+    /// If true, we assume the the executable bit is honored as part of the files mode. If false, we assume the file system
+    /// ignores the executable bit, hence it will be reported as 'off' even though we just tried to set it to be on.
+    pub file_mode: bool,
+    /// If true, the file system supports symbolic links and we should try to create them. Otherwise symbolic links will be checked
+    /// out as files which contain the link as text.
+    pub symlink: bool,
+}
+
+#[cfg(windows)]
+impl Default for Context {
+    fn default() -> Self {
+        Context {
+            precompose_unicode: false,
+            ignore_case: true,
+            file_mode: false,
+            symlink: false,
+        }
+    }
+}
+
+#[cfg(target_os = "macos")]
+impl Default for Context {
+    fn default() -> Self {
+        Context {
+            precompose_unicode: true,
+            ignore_case: true,
+            file_mode: true,
+            symlink: true,
+        }
+    }
+}
+
+#[cfg(all(unix, not(target_os = "macos")))]
+impl Default for Context {
+    fn default() -> Self {
+        Context {
+            precompose_unicode: false,
+            ignore_case: false,
+            file_mode: true,
+            symlink: true,
+        }
+    }
+}

git-worktree/src/index.rs

@@ -4,15 +4,10 @@ pub mod checkout {
     use bstr::BString;
     use quick_error::quick_error;
 
-    #[derive(Clone, Copy)]
+    #[derive(Default, Clone, Copy)]
     pub struct Options {
-        pub symlinks: bool,
-    }
-
-    impl Default for Options {
-        fn default() -> Self {
-            Options { symlinks: true }
-        }
+        /// capabilities of the file system
+        pub fs: crate::fs::Context,
     }
 
     quick_error! {
@@ -79,7 +74,9 @@ pub(crate) mod entry {
         entry_path: &BStr,
         find: &mut Find,
         root: &std::path::Path,
-        index::checkout::Options { symlinks }: index::checkout::Options,
+        index::checkout::Options {
+            fs: crate::fs::Context { symlink, .. },
+        }: index::checkout::Options,
         buf: &mut Vec<u8>,
     ) -> Result<(), index::checkout::Error>
     where
@@ -124,7 +121,7 @@ pub(crate) mod entry {
                 })?;
                 let symlink_destination = git_features::path::from_byte_slice(obj.data)
                     .map_err(|_| index::checkout::Error::IllformedUtf8 { path: obj.data.into() })?;
-                if symlinks {
+                if symlink {
                     #[cfg(unix)]
                     std::os::unix::fs::symlink(symlink_destination, &dest)?;
                     #[cfg(windows)]

git-worktree/src/lib.rs

@@ -6,63 +6,6 @@
 #![forbid(unsafe_code, rust_2018_idioms)]
 
 /// file system related utilities
-pub mod fs {
-    /// Common knowledge about the worktree that is needed across most interactions with the work tree
-    #[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
-    #[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]
-    pub struct Context {
-        /// If true, the filesystem will store paths as decomposed unicode, i.e. `ä` becomes `"a\u{308}"`, which means that
-        /// we have to turn these forms back from decomposed to precomposed unicode before storing it in the index or generally
-        /// using it. This also applies to input received from the command-line, so callers may have to be aware of this and
-        /// perform conversions accordingly.
-        /// If false, no conversions will be performed.
-        pub precompose_unicode: bool,
-        /// If true, the filesystem ignores the case of input, which makes `A` the same file as `a`.
-        /// This is also called case-folding.
-        pub ignore_case: bool,
-        /// If true, we assume the the executable bit is honored as part of the files mode. If false, we assume the file system
-        /// ignores the executable bit, hence it will be reported as 'off' even though we just tried to set it to be on.
-        pub file_mode: bool,
-        /// If true, the file system supports symbolic links and we should try to create them. Otherwise symbolic links will be checked
-        /// out as files which contain the link as text.
-        pub symlink: bool,
-    }
-
-    #[cfg(windows)]
-    impl Default for Context {
-        fn default() -> Self {
-            Context {
-                precompose_unicode: false,
-                ignore_case: true,
-                file_mode: false,
-                symlink: false,
-            }
-        }
-    }
-
-    #[cfg(target_os = "macos")]
-    impl Default for Context {
-        fn default() -> Self {
-            Context {
-                precompose_unicode: true,
-                ignore_case: true,
-                file_mode: true,
-                symlink: true,
-            }
-        }
-    }
-
-    #[cfg(all(unix, not(target_os = "macos")))]
-    impl Default for Context {
-        fn default() -> Self {
-            Context {
-                precompose_unicode: false,
-                ignore_case: false,
-                file_mode: true,
-                symlink: true,
-            }
-        }
-    }
-}
+pub mod fs;
 
 pub mod index;

git-worktree/tests/fixtures/make_ignorecase_collisions.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+set -eu -o pipefail
+
+git init -q
+git config commit.gpgsign false
+
+touch a A
+git add a
+echo A | git update-index --add --stdin
+
+git commit -m "init"

git-worktree/tests/index/mod.rs

@@ -15,19 +15,29 @@ mod checkout {
 
     #[test]
     fn allow_symlinks() -> crate::Result {
-        let opts = Default::default();
-        let (source_tree, destination) = setup_fixture_with_options(opts)?;
+        let opts = index::checkout::Options {
+            fs: git_worktree::fs::Context {
+                symlink: true,
+                ..Default::default()
+            },
+        };
+        let (source_tree, destination) = setup_fixture_with_options(opts, "make_mixed_without_submodules")?;
 
-        assert_equality(&source_tree, &destination, opts.symlinks)?;
+        assert_equality(&source_tree, &destination, opts.fs.symlink)?;
         Ok(())
     }
 
     #[test]
     fn symlinks_become_files_if_disabled() -> crate::Result {
-        let opts = index::checkout::Options { symlinks: false };
-        let (source_tree, destination) = setup_fixture_with_options(opts)?;
+        let opts = index::checkout::Options {
+            fs: git_worktree::fs::Context {
+                symlink: false,
+                ..Default::default()
+            },
+        };
+        let (source_tree, destination) = setup_fixture_with_options(opts, "make_mixed_without_submodules")?;
 
-        assert_equality(&source_tree, &destination, opts.symlinks)?;
+        assert_equality(&source_tree, &destination, opts.fs.symlink)?;
 
         Ok(())
     }
@@ -71,8 +81,11 @@ mod checkout {
         files
     }
 
-    fn setup_fixture_with_options(opts: git_worktree::index::checkout::Options) -> crate::Result<(PathBuf, TempDir)> {
-        let source_tree = fixture_path("make_repo");
+    fn setup_fixture_with_options(
+        opts: git_worktree::index::checkout::Options,
+        name: &str,
+    ) -> crate::Result<(PathBuf, TempDir)> {
+        let source_tree = fixture_path(name);
         let git_dir = source_tree.join(".git");
         let mut index = git_index::File::at(git_dir.join("index"), Default::default())?;
         let odb = git_odb::at(git_dir.join("objects"))?;