From 45b4e788fb60138516ed8e58a368d72d994da4c0 Mon Sep 17 00:00:00 2001
From: Tony Zorman <soliditsallgood@mailbox.org>
Date: Sat, 3 Jun 2023 14:23:19 +0200
Subject: [PATCH] eshell-next-prompt: More precisely navigate to the prompt
 (bug#63748)

* lisp/eshell/em-prompt.el (eshell-next-prompt): Navigate to the
current prompt more accurately by using text properties instead of
going to the beginning of the line.  This is important for multiline
prompts, as they don't necessarily start at the beginning of the
current line.

* test/lisp/eshell/em-prompt-tests.el
(em-prompt-test/multiline):
Test a given function with a multiline prompt.

(em-prompt-test/next-previous-prompt-with):
(em-prompt-test/forward-backward-matching-input-with):
Helper functions for code reuse.

(em-prompt-test/forward-backward-matching-input):
(em-prompt-test/next-previous-prompt):
Rewrite in terms of the appropriate helper functions.

(em-prompt-test/next-previous-prompt-multiline):
(em-prompt-test/forward-backward-matching-input-multiline):
Add multiline variants of existing tests.
---
 lisp/eshell/em-prompt.el            |  3 +-
 test/lisp/eshell/em-prompt-tests.el | 45 ++++++++++++++++++++++++++---
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/lisp/eshell/em-prompt.el b/lisp/eshell/em-prompt.el
index 9f9e58e83d..42f8f273b5 100644
--- a/lisp/eshell/em-prompt.el
+++ b/lisp/eshell/em-prompt.el
@@ -180,7 +180,8 @@ eshell-next-prompt
                   (text-property-search-forward 'field 'prompt t))
         (setq n (1- n)))
     (let (match this-match)
-      (forward-line 0)           ; Don't count prompt on current line.
+      ;; Don't count the current prompt.
+      (text-property-search-backward 'field 'prompt t)
       (while (and (< n 0)
                   (setq this-match (text-property-search-backward
                                     'field 'prompt t)))
diff --git a/test/lisp/eshell/em-prompt-tests.el b/test/lisp/eshell/em-prompt-tests.el
index 257549e40f..7e3454a4d3 100644
--- a/test/lisp/eshell/em-prompt-tests.el
+++ b/test/lisp/eshell/em-prompt-tests.el
@@ -80,9 +80,27 @@ em-prompt-test/field-properties/no-highlight
                 (apply #'propertize "hello\n"
                        eshell-command-output-properties)))))))
 
-(ert-deftest em-prompt-test/next-previous-prompt ()
-  "Check that navigating forward/backward through old prompts works correctly."
+(defun em-prompt-test/multiline (test-fun)
+  "Execute TEST-FUN with a multiline prompt."
+  (funcall
+   test-fun
+   '(progn
+      (setq eshell-prompt-function
+            (lambda ()
+              (concat "┌─"
+                      (user-login-name) "@" (system-name)
+                      " " (abbreviate-file-name (eshell/pwd)) " \n"
+                      "└─"
+                      (if (zerop (user-uid)) "#" "$")
+                      " ")))
+      (setq eshell-prompt-regexp "└─[$#] "))))
+
+(defun em-prompt-test/next-previous-prompt-with (&optional more)
+  "Helper for checking forward/backward navigation of old prompts.
+Accepts an additional argument, to be executed inside of a
+temporary eshell buffer."
   (with-temp-eshell
+   (eval more)
    (eshell-insert-command "echo one")
    (eshell-insert-command "echo two")
    (eshell-insert-command "echo three")
@@ -98,9 +116,20 @@ em-prompt-test/next-previous-prompt
    (eshell-next-prompt 3)
    (should (equal (eshell-get-old-input) "echo fou"))))
 
-(ert-deftest em-prompt-test/forward-backward-matching-input ()
-  "Check that navigating forward/backward via regexps works correctly."
+(ert-deftest em-prompt-test/next-previous-prompt ()
+  "Check that navigating forward/backward through old prompts works correctly."
+  (em-prompt-test/next-previous-prompt-with))
+
+(ert-deftest em-prompt-test/next-previous-prompt-multiline ()
+  "Check old prompt forward/backward navigation for multiline prompts."
+  (em-prompt-test/multiline #'em-prompt-test/next-previous-prompt-with))
+
+(defun em-prompt-test/forward-backward-matching-input-with (&optional more)
+  "Helper for checking forward/backward navigation via regexps.
+Accepts an additional argument, to be executed inside of a
+temporary eshell buffer."
   (with-temp-eshell
+   (eval more)
    (eshell-insert-command "echo one")
    (eshell-insert-command "printnl something else")
    (eshell-insert-command "echo two")
@@ -117,4 +146,12 @@ em-prompt-test/forward-backward-matching-input
    (eshell-forward-matching-input "echo" 3)
    (should (equal (eshell-get-old-input) "echo fou"))))
 
+(ert-deftest em-prompt-test/forward-backward-matching-input ()
+  "Check that navigating forward/backward via regexps works correctly."
+  (em-prompt-test/forward-backward-matching-input-with))
+
+(ert-deftest em-prompt-test/forward-backward-matching-input-multiline ()
+  "Check forward/backward regexp navigation for multiline prompts."
+  (em-prompt-test/multiline #'em-prompt-test/forward-backward-matching-input-with))
+
 ;;; em-prompt-tests.el ends here
-- 
2.40.1