better error handling on close (#301)

There is still some work to be done to deal with all the special errors
we see now for some reason.

Author: Byron

git-worktree/src/index/checkout.rs

@@ -219,8 +219,6 @@ pub enum Error<E: std::error::Error + Send + Sync + 'static> {
     Time(#[from] std::time::SystemTimeError),
     #[error("IO error while writing blob or reading file metadata or changing filetype")]
     Io(#[from] std::io::Error),
-    #[error(transparent)]
-    FileClose(#[from] close_file::CloseError),
     #[error("object {} for checkout at {} could not be retrieved from object database", .oid.to_hex(), .path.display())]
     Find {
         #[source]

git-worktree/src/index/entry.rs

@@ -70,7 +70,7 @@ where
             // NOTE: we don't call `file.sync_all()` here knowing that some filesystems don't handle this well.
             //       revisit this once there is a bug to fix.
             update_fstat(entry, file.metadata()?)?;
-            // file.close()?;
+            file.close().map_err(|err| err.unwrap() /* misnomer, won't panic */)?;
             obj.data.len()
         }
         git_index::entry::Mode::SYMLINK => {
@@ -91,7 +91,8 @@ where
                     open_options(p, destination_is_initially_empty, overwrite_existing).open(&dest)
                 })?;
                 file.write_all(obj.data)?;
-                file.close()?;
+                file.close()
+                    .map_err(|err| err.unwrap() /* misnomer for 'into inner' */)?;
             }
 
             update_fstat(entry, std::fs::symlink_metadata(&dest)?)?;