Bug: linum-mode + org-indent-mode cursor movement problems [8.2.10 (release_8.2.10 @ /usr/share/emacs/25.2/lisp/org/)]

[Tom Schutter <t.schutter@comcast.net>]

If both linum-mode (or nlinum-mode) and org-indent-mode are enabled, 
then moving the cursor to the previous line using <up> causes it to jump 
horizontally to the right.  The jump matches the current indentation.  I 
would expect the cursor to remain in the same column.

Load linum.org (contents below) with minimal config.  linum.org will 
enable linum-mode and org-indent-mode:

   emacs -Q linum.org

Place your cursor on the "2" in the fourth line and press <up>.  The 
cursor will jump two columns to the right to the "4" in the third line. 
Press <up> again and the cursor will move to the "4" in the second line. 
  Press <up> again and the cursor will jump back to the "e" in the first 
line.

What is interesting is that you get different behavior when using 
<down>.  The cursor remains in the same column as you move down each 
line.  So starting on the "e" in the first line, pressing <down> moves 
the cursor to the "2" on the second line.

If you insert a second level heading in between the first and the second 
line, then the jumps will be four columns instead of two.

I discovered this problem first in nlimum-mode, but it is easier to 
reproduce using linum-mode when starting Emacs with -Q.

Contents of linum.org:

   * heading
   1234 line 2
   1234 line 3
   1234 line 4
   # Local Variables:
   # eval: (org-indent-mode 1)
   # eval: (linum-mode 1)
   # End:


Emacs  : GNU Emacs 25.2.2 (x86_64-pc-linux-gnu, GTK+ Version 3.22.21)
  of 2017-09-22, modified by Debian
Package: Org-mode version 8.2.10 (release_8.2.10 @ 
/usr/share/emacs/25.2/lisp/org/)

current state:
==============
(setq
  org-tab-first-hook '(org-hide-block-toggle-maybe
               org-src-native-tab-command-maybe
               org-babel-hide-result-toggle-maybe
               org-babel-header-arg-expand)
  org-speed-command-hook '(org-speed-command-default-hook
               org-babel-speed-command-hook)
  org-occur-hook '(org-first-headline-recenter)
  org-metaup-hook '(org-babel-load-in-session-maybe)
  org-confirm-shell-link-function 'yes-or-no-p
  org-after-todo-state-change-hook '(org-clock-out-if-current)
  org-src-mode-hook '(org-src-babel-configure-edit-buffer
              org-src-mode-configure-edit-buffer)
  org-agenda-before-write-hook '(org-agenda-add-entry-text)
  org-babel-pre-tangle-hook '(save-buffer)
  org-mode-hook '(#[nil "\300\301\302\303\304$\207"
            [org-add-hook change-major-mode-hook org-show-block-all
             append local]
            5]
          #[nil "\300\301\302\303\304$\207"
            [org-add-hook change-major-mode-hook
             org-babel-show-result-all append local]
            5]
          org-babel-result-hide-spec org-babel-hide-all-hashes)
  org-ctrl-c-ctrl-c-hook '(org-babel-hash-at-point
               org-babel-execute-safely-maybe)
  org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-hide-drawers
           org-cycle-hide-inline-tasks org-cycle-show-empty-lines
           org-optimize-window-after-visibility-change)
  org-confirm-elisp-link-function 'yes-or-no-p
  org-metadown-hook '(org-babel-pop-to-session-maybe)
  org-clock-out-hook '(org-clock-remove-empty-clock-drawer)
  )