move-beginning-of-line move to wrong position on heading when markdown-hide-markup is enabled

[kuranari]

When markdown-hide-markup is enabled, invoking move-beginning-of-line （C-a） on a header line incorrectly moves the cursor to the previous line.

Headings do not use the invisible property. However, this appears to be an intentional choice. #130 (comment)

Expected Behavior

• Move to beginning of current line

Actual Behavior

• Move to previouse line

Steps to Reproduce

1. Place the following in /tmp/emacs/.emacs:

(setq custom-file "/dev/null")

(package-initialize)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/"))
(package-install 'markdown-mode)
 
(setq markdown-hide-markup t)

2. Make sample.md

text

# Heading 

3. HOME=/tmp/emacs emacs -Q --load /tmp/emacs/.emacs /tmp/emacs/sample.md
4. Move to line 3
5. Hit C-a (move-beginning-of-line）

Screenshot

default.mov

Software Versions

• Markdown Mode: 2.7-alpha
• Emacs: GNU Emacs 29.1
• OS: macOS Sonoma 14.1

[kuranari]

📝 Research Findings

When evaluating the following, it no longer moves to the previous line (not a fundamental solution).

(setq global-disable-point-adjustment t)

https://www.gnu.org/software/emacs/manual/html_node/elisp/Adjusting-Point.html