bug#71533: 30.0.50; [PATCH] Calc: fix calc-trail-here on initial line of trail.

[Ashwin Kafle]

Hello,

On Calc-trail, you cannot access the first element of trail using ``t
['' or going to the first line and doing (calc-trail-here). This is
because the check of empty buffer has small error.

Attached is a simple fix for that.

>From ea1822bf39aa5236368567f067064b1a2c2c6361 Mon Sep 17 00:00:00 2001
From: Ashwin Kafle <ashwin@ashwink.com.np>
Date: Thu, 13 Jun 2024 16:06:38 +0545
Subject: [PATCH] Fix calc-trail-here for first line of trail.

* lisp/calc/calc.el(calc-trail-here): change 'or' to 'and'
since (bobp) return true even if the buffer is not empty.
---
 lisp/calc/calc.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/calc/calc.el b/lisp/calc/calc.el
index e6448625cee..f92e4958e33 100644
--- a/lisp/calc/calc.el
+++ b/lisp/calc/calc.el
@@ -2184,7 +2184,7 @@ calc-trail-here
        (beginning-of-line)
        (if (eobp)
             (forward-line -1))
-       (if (or (bobp) (eobp))
+       (if (and (bobp) (eobp))
            (setq overlay-arrow-position nil)   ; trail is empty
          (set-marker calc-trail-pointer (point) (current-buffer))
          (setq calc-trail-overlay (concat (buffer-substring (point)
-- 
2.45.1

Cheers!