From e1e0bce5b3a2fcdaf966e450d86a2fb4b22376a7 Mon Sep 17 00:00:00 2001
From: Jim Porter <jporterbugs@gmail.com>
Date: Wed, 11 Oct 2023 11:38:27 -0700
Subject: [PATCH] Fix behavior of Eshell prompt when yanking output into it

* lisp/eshell/esh-util.el (eshell--unmark-string-as-output): New
function...

* lisp/eshell/esh-mode.el (eshell-mode): ... use it.

* test/lisp/eshell/eshell-tests.el (eshell-test/yank-output): New test
(bug#66469).
---
 lisp/eshell/esh-mode.el          |  3 +++
 lisp/eshell/esh-util.el          |  8 ++++++++
 test/lisp/eshell/eshell-tests.el | 19 +++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/lisp/eshell/esh-mode.el b/lisp/eshell/esh-mode.el
index 2b560afb92c..9d2cd1e67eb 100644
--- a/lisp/eshell/esh-mode.el
+++ b/lisp/eshell/esh-mode.el
@@ -361,6 +361,9 @@ eshell-mode
   (setq-local eshell-last-output-end (point-marker))
   (setq-local eshell-last-output-block-begin (point))
 
+  (add-function :filter-return (local 'filter-buffer-substring-function)
+                #'eshell--unmark-string-as-output)
+
   (let ((modules-list (copy-sequence eshell-modules-list)))
     (setq-local eshell-modules-list modules-list))
 
diff --git a/lisp/eshell/esh-util.el b/lisp/eshell/esh-util.el
index 4c251a29269..ca2f775318a 100644
--- a/lisp/eshell/esh-util.el
+++ b/lisp/eshell/esh-util.el
@@ -234,6 +234,14 @@ eshell--mark-yanked-as-output
                 (eshell--mark-as-output start1 end1)))))
     (add-hook 'after-change-functions hook nil t)))
 
+(defun eshell--unmark-string-as-output (string)
+  "Unmark STRING as Eshell output."
+  (remove-list-of-text-properties
+   0 (length string)
+   '(rear-nonsticky front-sticky field insert-in-front-hooks)
+   string)
+  string)
+
 (defun eshell-find-delimiter
   (open close &optional bound reverse-p backslash-p)
   "From point, find the CLOSE delimiter corresponding to OPEN.
diff --git a/test/lisp/eshell/eshell-tests.el b/test/lisp/eshell/eshell-tests.el
index b02e5fca592..d2ef44ae507 100644
--- a/test/lisp/eshell/eshell-tests.el
+++ b/test/lisp/eshell/eshell-tests.el
@@ -195,6 +195,25 @@ eshell-test/get-old-input/run-output
    (eshell-send-input)
    (eshell-match-output "(\"hello\" \"there\")")))
 
+(ert-deftest eshell-test/yank-output ()
+  "Test that yanking a line of output into the next prompt works (bug#66469)."
+  (with-temp-eshell
+   (eshell-insert-command "echo hello")
+   ;; Go to the output and kill the line of text.
+   (forward-line -1)
+   (kill-line)
+   ;; Go to the last prompt and yank the previous output.
+   (goto-char (point-max))
+   (yank)
+   ;; Go to the beginning of the prompt and add some text.
+   (move-beginning-of-line 1)
+   (insert-and-inherit "echo ")
+   ;; Make sure when we go to the beginning of the line, we go to the
+   ;; right spot (before the "echo").
+   (move-end-of-line 1)
+   (move-beginning-of-line 1)
+   (should (looking-at "echo hello"))))
+
 (provide 'eshell-tests)
 
 ;;; eshell-tests.el ends here
-- 
2.25.1