working_copy: handle symlink outside write_path_to_store()

The `write_path_to_store()` has almost no overlapping code between the
handling of symlinks and regular files, which suggests that we should
move out the handling of symlinks to the caller (there's only one).

lib/src/local_working_copy.rs

@@ -1068,12 +1068,20 @@ impl TreeState {
         } else {
             let new_file_type = new_file_state.file_type.clone();
             let current_tree_values = current_tree.path_value(repo_path);
-            let new_tree_values = self.write_path_to_store(
-                repo_path,
-                &disk_path,
-                &current_tree_values,
-                new_file_type,
-            )?;
+            let new_tree_values = match new_file_type {
+                FileType::Normal { executable } => self.write_path_to_store(
+                    repo_path,
+                    &disk_path,
+                    &current_tree_values,
+                    executable,
+                )?,
+                FileType::Symlink => {
+                    let id = self.write_symlink_to_store(repo_path, &disk_path)?;
+                    Merge::normal(TreeValue::Symlink(id))
+                }
+                FileType::GitSubmodule => panic!("git submodule cannot be written to store"),
+            };
+
             if new_tree_values != current_tree_values {
                 Ok(Some(new_tree_values))
             } else {
@@ -1087,17 +1095,8 @@ impl TreeState {
         repo_path: &RepoPath,
         disk_path: &Path,
         current_tree_values: &MergedTreeValue,
-        file_type: FileType,
+        executable: FileExecutableFlag,
     ) -> Result<MergedTreeValue, SnapshotError> {
-        let executable = match file_type {
-            FileType::Normal { executable } => executable,
-            FileType::Symlink => {
-                let id = self.write_symlink_to_store(repo_path, disk_path)?;
-                return Ok(Merge::normal(TreeValue::Symlink(id)));
-            }
-            FileType::GitSubmodule => panic!("git submodule cannot be written to store"),
-        };
-
         // If the file contained a conflict before and is now a normal file on disk, we
         // try to parse any conflict markers in the file into a conflict.
         if let Some(current_tree_value) = current_tree_values.as_resolved() {