如何在Linux下让eshell-autojump不区分大小写

Question

在 Linux 下，eshell-autojump 会进行区分大小写的匹配，我觉得这很麻烦。我试图通过建议 eshell/j 使用总是返回 t 的 eshell-under-windows-p 来规避这个问题，但令我懊恼的是在 eshell/j 中调用的 eshell-under-windows-p 是不受 cl-letf 的影响。我修改了我的 eshell/j 来给我一些调试信息：

;; Modified eshell/j inside eshell-autojump.el to this

(defun eshell/j (&rest args)           ; all but first ignored
  "Jump to a directory you often cd to.
This compares the argument with the list of directories you usually jump to.
Without an argument, list the ten most common directories.
With a positive integer argument, list the n most common directories.
Otherwise, call `eshell/cd' with the result."
  (setq args (eshell-flatten-list args))
  (let ((path (car args))
        (candidates (eshell-autojump-candidates))
        (case-fold-search (eshell-under-windows-p))
        result)
    (when (not path)
      (setq path 10))
    (message "case-fold-search = %S" case-fold-search)
    (message "eshell-under-windows-p returns %s from inside eshell/j" (eshell-under-windows-p))
    (if (and (integerp path) (> path 0))
        (progn
          (let ((n (nthcdr (1- path) candidates)))
            (when n
              (setcdr n nil)))
          (eshell-lisp-command (mapconcat 'identity candidates "\n")))
      (while (and candidates (not result))
        (if (string-match path (car candidates))
            (setq result (car candidates))
          (setq candidates (cdr candidates))))
      (eshell/cd result))))

我的 init.el 添加了建议，试图通过欺骗它认为我们在 Windows 上来尝试使 eshell/j 无大小写：

;; Added to init.el
  (require 'eshell-autojump)
  (advice-add 'eshell/j :around
    (lambda (orig-fun &rest xs)
      (cl-letf (((symbol-function 'eshell-under-windows-p) (lambda () t)))
        (progn (message "eshell-under-windows-p returns %s from lambda" (eshell-under-windows-p)) (apply orig-fun xs)))))

但是当我尝试跳转到 eshell 时，我在 Messages 缓冲区中得到的只是：

;; I get in *Messages*
eshell-under-windows-p returns t from lambda
case-fold-search = nil
eshell-under-windows-p returns nil from inside eshell/j

我对 elisp 的菜鸟知识不足以解决这里可能的范围界定问题。谁能解码为什么从 eshell/j 调用时 eshell-under-window-p 不受影响？

Answer 1

我找到了答案。 cl-letf 不适用于字节编译函数。由于 eshell-autojump 是一个软件包，它在安装时会进行字节编译，并且 cl-letf 不能用于修改其内部行为。

最后我成功地通过以下方式欺骗 eshell/j 使其不区分大小写：

  (defun my/eshell-j-case-insensitive (orig-fun &rest args)
    "Advice function to make `eshell/j' case-insensitive."
    (let ((original-system-type system-type))
      (unwind-protect
        (progn
          (setq system-type 'windows-nt) ; Temporarily set system-type to Windows
          (apply orig-fun args))
        (setq system-type original-system-type)))) ; Restore the original system-type
  (advice-add 'eshell/j :around #'my/eshell-j-case-insensitive)