Bug: Unintended column added to table [9.4.6 (9.4.6-gab9f2a @ /home/user/.emacs.d/elpa/org-9.4.6/)]

[spectria]

In a preexisting org table, hitting <tab> can add a new, unintended column

To reproduce the behavior:

1) Create foo.org containing:
   
   | Type |
   | foo  |
   |      |
   
2) emacs -Q
3) M-x package-initialize
4) C-x C-f foo.org
5) Repeat:
   1) Put cursor at end of line containing foo
   2) <tab>

Bug: After the 2nd iteration, org adds a unintended new column. Further 
iteration adds more columns.


======================================================================

Emacs  : GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2021-01-30, modified by Debian
Package: Org mode version 9.4.6 (9.4.6-gab9f2a @ 
/home/user/.emacs.d/elpa/org-9.4.6/)

current state:
==============
(setq
 org-src-mode-hook '(org-src-babel-configure-edit-buffer 
org-src-mode-configure-edit-buffer)
 org-link-shell-confirm-function 'yes-or-no-p
 org-metadown-hook '(org-babel-pop-to-session-maybe)
 org-clock-out-hook '(org-clock-remove-empty-clock-drawer)
 org-reveal-start-hook '(org-decrypt-entry)
 org-mode-hook '(#[0 "\300\301\302\303\304$\207" [add-hook 
change-major-mode-hook org-show-all append local] 5]
                 #[0 "\300\301\302\303\304$\207" [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-archive-hook '(org-attach-archive-delete-maybe)
 org-confirm-elisp-link-function 'yes-or-no-p
 org-agenda-before-write-hook '(org-agenda-add-entry-text)
 org-metaup-hook '(org-babel-load-in-session-maybe)
 org-bibtex-headline-format-function #[257 "\300
\236A\207" [:title] 3 "\n\n(fn 
ENTRY)"]
 org-babel-pre-tangle-hook '(save-buffer)
 org-tab-first-hook '(org-babel-hide-result-toggle-maybe 
org-babel-header-arg-expand)
 org-agenda-loop-over-headlines-in-active-region nil
 org-occur-hook '(org-first-headline-recenter)
 org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-hide-drawers 
org-cycle-show-empty-lines
                  org-optimize-window-after-visibility-change)
 org-speed-command-hook '(org-speed-command-activate 
org-babel-speed-command-activate)
 org-export-before-parsing-hook '(org-attach-expand-links)
 org-confirm-shell-link-function 'yes-or-no-p
 org-link-parameters '(("attachment" :follow org-attach-follow :complete 
org-attach-complete-link) ("id" :follow org-id-open)
                       ("eww" :follow org-eww-open :store org-eww-store-link) 
("rmail" :follow org-rmail-open :store org-rmail-store-link)
                       ("mhe" :follow org-mhe-open :store org-mhe-store-link)
                       ("irc" :follow org-irc-visit :store org-irc-store-link 
:export org-irc-export)
                       ("info" :follow org-info-open :export org-info-export 
:store org-info-store-link)
                       ("gnus" :follow org-gnus-open :store org-gnus-store-link)
                       ("docview" :follow org-docview-open :export 
org-docview-export :store org-docview-store-link)
                       ("bibtex" :follow org-bibtex-open :store 
org-bibtex-store-link)
                       ("bbdb" :follow org-bbdb-open :export org-bbdb-export 
:complete org-bbdb-complete-link :store org-bbdb-store-link)
                       ("w3m" :store org-w3m-store-link) ("file+sys") 
("file+emacs") ("shell" :follow org-link--open-shell)
                       ("news" :follow #[514 "\301\300\302Q\"\207" ["news" 
browse-url ":"] 6 "\n\n(fn URL ARG)"])
                       ("mailto" :follow #[514 "\301\300\302Q\"\207" 
["mailto" browse-url ":"] 6 "\n\n(fn URL ARG)"])
                       ("https" :follow #[514 "\301\300\302Q\"\207" ["https" 
browse-url ":"] 6 "\n\n(fn URL ARG)"])
                       ("http" :follow #[514 "\301\300\302Q\"\207" ["http" 
browse-url ":"] 6 "\n\n(fn URL ARG)"])
                       ("ftp" :follow #[514 "\301\300\302Q\"\207" ["ftp" 
browse-url ":"] 6 "\n\n(fn URL ARG)"])
                       ("help" :follow org-link--open-help) ("file" :complete 
org-link-complete-file) ("elisp" :follow org-link--open-elisp)
                       ("doi" :follow org-link--open-doi))
 org-link-elisp-confirm-function 'yes-or-no-p
 )