merge(3p/git): Merge git upstream at v2.26.2

third_party/git/worktree.h

@@ -44,13 +44,29 @@ int submodule_uses_worktrees(const char *path);
 const char *get_worktree_git_dir(const struct worktree *wt);
 
 /*
- * Search a worktree that can be unambiguously identified by
- * "arg". "prefix" must not be NULL.
+ * Search for the worktree identified unambiguously by `arg` -- typically
+ * supplied by the user via the command-line -- which may be a pathname or some
+ * shorthand uniquely identifying a worktree, thus making it convenient for the
+ * user to specify a worktree with minimal typing. For instance, if the last
+ * component (say, "foo") of a worktree's pathname is unique among worktrees
+ * (say, "work/foo" and "work/bar"), it can be used to identify the worktree
+ * unambiguously.
+ *
+ * `prefix` should be the `prefix` handed to top-level Git commands along with
+ * `argc` and `argv`.
+ *
+ * Return the worktree identified by `arg`, or NULL if not found.
  */
 struct worktree *find_worktree(struct worktree **list,
 			       const char *prefix,
 			       const char *arg);
 
+/*
+ * Return the worktree corresponding to `path`, or NULL if no such worktree
+ * exists.
+ */
+struct worktree *find_worktree_by_path(struct worktree **, const char *path);
+
 /*
  * Return true if the given worktree is the main one.
  */