bug#21818: 24.5; org-set-tags-to indentation problems when called programmatically

[mail]

1. Start emacs with emacs -Q
2. Evaluate the following:

(require 'org-mode)

(defun bad-indent ()
  (interactive)
  (insert "* ")
  (org-insert-link nil "http://www.example.com/foo/bar/baz/qux/abc123f56789"; 
"something")
  (org-set-tags-to '("foo")))

3. Switch to an empty buffer
4. M-x org-mode
5. M-x bad-indent
6. The result looks like the following (except with an actual hyperlink):

* something     :foo:

This indentation is incorrect. If you follow the steps for `bad-indent'
interactively (or even using edebug), the indentation looks like:

* something                                                             :foo:

Digging in some more, it looks like the problem is the `current-column'
call in `org-set-tags' (where it says 'setq c0 (current-column)', on
line 14620 of org.el in my distribution). With some instrumentation,
`current-column' seems to be giving different values in interactive mode
than programatically; I'm guessing it has something to do with the long
link target causing the value to be different.



In GNU Emacs 24.5.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.16.6)
 of 2015-09-09 on foutrelis
Windowing system distributor `The X.Org Foundation', version 11.0.11704000
System Description:     Arch Linux

Configured using:
 `configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --with-x-toolkit=gtk3 --with-xft
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong
 --param=ssp-buffer-size=4' CPPFLAGS=-D_FORTIFY_SOURCE=2
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro'

Important settings:
  value of $LANG: en_US.utf8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Mark set
bad-indent
<XF86PowerOff> is undefined
bad-indent
Quit
You can run the command `org-insert-link' with C-c C-l
Making completion list... [2 times]
nil

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rfc822 mml mml-sec mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mm-util help-fns mail-prsvr
mail-utils help-mode tabify image-file org-element org-rmail org-mhe
org-irc org-info org-gnus gnus-util org-docview doc-view jka-compr
image-mode dired cl-loaddefs cl-lib org-bibtex bibtex org-bbdb org-w3m
org org-macro org-footnote org-pcomplete pcomplete org-list org-faces
org-entities noutline outline easy-mmode org-version ob-emacs-lisp ob
ob-tangle ob-ref ob-lob ob-table ob-exp org-src ob-keys ob-comint comint
ansi-color ring ob-core ob-eval org-compat org-macs org-loaddefs
format-spec find-func cal-menu easymenu calendar cal-loaddefs time-date
tooltip electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
x-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list
newcomment lisp-mode prog-mode register page menu-bar rfn-eshadow timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai
tai-viet lao korean japanese hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help
simple abbrev minibuffer nadvice loaddefs button faces cus-face macroexp
files text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
dbusbind gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 133855 6759)
 (symbols 48 24865 0)
 (miscs 40 81 451)
 (strings 32 33885 4710)
 (string-bytes 1 1030329)
 (vectors 16 16015)
 (vector-slots 8 456618 6166)
 (floats 8 108 286)
 (intervals 56 332 0)
 (buffers 960 13)
 (heap 1024 52252 997))