feat!: Repository::prefix() turns Option<Result into Result<Option.

This makes it easier for the caller as they won't have to call transpose anymore.

Author: Byron

gix/src/repository/location.rs

@@ -45,27 +45,30 @@ impl crate::Repository {
     /// Note that there may be `None` if there is no work tree, even though the `PathBuf` will be empty
     /// if the CWD is at the root of the work tree.
     // TODO: tests, details - there is a lot about environment variables to change things around.
-    pub fn prefix(&self) -> Option<std::io::Result<PathBuf>> {
-        self.work_tree.as_ref().map(|root| {
-            std::env::current_dir().and_then(|cwd| {
-                gix_path::realpath_opts(root, &cwd, MAX_SYMLINKS)
-                    .map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err))
-                    .and_then(|root| {
-                        cwd.strip_prefix(&root)
-                            .map_err(|_| {
-                                std::io::Error::new(
-                                    std::io::ErrorKind::Other,
-                                    format!(
-                                        "CWD '{}' isn't within the work tree '{}'",
-                                        cwd.display(),
-                                        root.display()
-                                    ),
-                                )
-                            })
-                            .map(ToOwned::to_owned)
-                    })
+    pub fn prefix(&self) -> std::io::Result<Option<PathBuf>> {
+        self.work_tree
+            .as_ref()
+            .map(|root| {
+                std::env::current_dir().and_then(|cwd| {
+                    gix_path::realpath_opts(root, &cwd, MAX_SYMLINKS)
+                        .map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err))
+                        .and_then(|root| {
+                            cwd.strip_prefix(&root)
+                                .map_err(|_| {
+                                    std::io::Error::new(
+                                        std::io::ErrorKind::Other,
+                                        format!(
+                                            "CWD '{}' isn't within the work tree '{}'",
+                                            cwd.display(),
+                                            root.display()
+                                        ),
+                                    )
+                                })
+                                .map(ToOwned::to_owned)
+                        })
+                })
             })
-        })
+            .transpose()
     }
 
     /// Return the kind of repository, either bare or one with a work tree.