There is something that has always bugged me which can be potentially fixed in a few lines. I wanted to share it with you.
Problem
I type a long prompt; maybe I spend 3 minutes crafting it, and then I want to move a few paragraphs up (e.g., I use an agent to write prose and ask it to improve my text). I often end up typing C-up and C-down arrows because of muscle memory. This has unpleasant consequences because, as the prompt rolls to the previous one, I am no longer able to recover the prompt I was writing. Rolling back to a previous prompt is a great feature to have—sometimes it is precisely what I need. However, I often want to be able to roll back to the prompt I am composing. Currently, this is not possible. The prompt I was typing is gone, and I need to type it again—something frustrating.
Solution
Comint already has a solution, and agent-shell makes use of it, but the input that gets stashed is truncated because shell-maker overrides comint-get-old-input with a forward-sexp-based grabber. For prose, like when prompting an agent, the truncation implemented by shell-maker is the wrong behavior. The fix is just two/three lines. While it perfectly works for me with a hook, I thought you may want to share this fix with all your users by integrating something like this directly into upstream:
;; History navigation: preserve the full in-progress prompt. shell-maker sets
;; `comint-get-old-input' to a function that grabs a single `forward-sexp', so
;; multi-word/multi-line prompts are truncated when comint stashes them on the
;; first C-up. Override to capture the entire input region; comint's built-in
;; `comint-restore-input' then brings the full text back when C-down
;; overshoots the newest history entry.
(defun my/agent-shell-get-old-input ()
"Return the entire pending input from process-mark to point-max."
(when-let ((proc (get-buffer-process (current-buffer))))
(buffer-substring-no-properties (process-mark proc) (point-max))))
(add-hook 'agent-shell-mode-hook
(lambda ()
(setq-local comint-get-old-input
#'my/agent-shell-get-old-input)))If you like, I can open a PR with a suggestion so that we can discuss the concrete implementation in the code. Or perhaps you prefer to implement the few lines of code above, which essentially fix comint-get-old-input (already used in agent-shell).
Checklist
There is something that has always bugged me which can be potentially fixed in a few lines. I wanted to share it with you.
Problem
I type a long prompt; maybe I spend 3 minutes crafting it, and then I want to move a few paragraphs up (e.g., I use an agent to write prose and ask it to improve my text). I often end up typing C-up and C-down arrows because of muscle memory. This has unpleasant consequences because, as the prompt rolls to the previous one, I am no longer able to recover the prompt I was writing. Rolling back to a previous prompt is a great feature to have—sometimes it is precisely what I need. However, I often want to be able to roll back to the prompt I am composing. Currently, this is not possible. The prompt I was typing is gone, and I need to type it again—something frustrating.
Solution
Comint already has a solution, and agent-shell makes use of it, but the input that gets stashed is truncated because shell-maker overrides comint-get-old-input with a forward-sexp-based grabber. For prose, like when prompting an agent, the truncation implemented by shell-maker is the wrong behavior. The fix is just two/three lines. While it perfectly works for me with a
hook, I thought you may want to share this fix with all your users by integrating something like this directly into upstream:If you like, I can open a PR with a suggestion so that we can discuss the concrete implementation in the code. Or perhaps you prefer to implement the few lines of code above, which essentially fix comint-get-old-input (already used in agent-shell).
Checklist
67babec(2026-05-16, merge of Add Hermes Agent Support #583)03099fa(2026-05-03, merge of Add support for devcontainer #18)agent-shell-opencode.el, bundled with agent-shell)opencode0.0.0-integrated-202605150926(personal fork with--attachsupport; see config below)