how to prevent faces from bleeding onto surrounding areas of buffer?

Question

Q: How do I keep org-mode link faces from bleeding over into the ... selective display characters at the end of a folded header?

This is a visual tick that drives me a little nutty. When, in org-mode, a link is the very last thing on a line, the link face bleeds over into the ... that indicates that the header is folded up. If there is, say, a blank space after the link, there is no bleeding.

The screenshot I've posted demonstrates the issue. Line three is the problematic line with no characters between the end of the link and the end of line, while line four shows a link, followed by a space:

First of all, why does this happen? Second, and more to the point, how do I make it stop?

UPDATE 1: As per comments, posted below are screenshots of the buffer with the headers closed and open. I've opened Emacs with no init file (ie, emacs -Q), required org-mode, and opened this example file. So: it does not appear to be something kooky in my setup.

All headers closed:

All headers open:

The theme I'd been using above is inkpot, although I get the same problem when using the solarized theme as well as the default theme (as in the new screenshots).

Emacs version is 24.3.1. I get the same results when using org version 7.9.3f (ie, the one bundled with that Emacs version), as well as 8.3beta.

UPDATE 2: here's a minimum working example in response to a comment request:

* here's a header with a [[~/somefile.txt][link at the end]]

  - This one's a problem
  - Interesting note:
    + put the cursor immediately *after* the *d* in "end" with the
      header closed/folded
      * the face no longer bleeds over into the dots
    + move the cursor anywhere else
      * the face bleeds over into the dots again

* here's another [[~/someotherfile.txt][go at it]]
  DEADLINE: <2014-10-26 Sun>

  - This one's also a problem

* here's another header with a [[~/anotherfile.txt][link followed by a space]] 

  - No bleed-over onto the dots with this one

Answer 1

This looks like a bug triggered by org-mode's org-activate-bracket-links function.

This is what this function looks like:

(defun org-activate-bracket-links (limit)
  "Run through the buffer and add overlays to bracketed links."
  (if (and (re-search-forward org-bracket-link-regexp limit t)
       (not (org-in-src-block-p)))
      (let* ((hl (org-match-string-no-properties 1))
         (help (concat "LINK: " (save-match-data (org-link-unescape hl))))
         (ip (org-maybe-intangible
          (list 'invisible 'org-link
            'keymap org-mouse-map 'mouse-face 'highlight
            'font-lock-multiline t 'help-echo help
            'htmlize-link `(:uri ,hl))))
         (Vp (list 'keymap org-mouse-map 'mouse-face 'highlight
               'font-lock-multiline t 'help-echo help
               'htmlize-link `(:uri ,hl))))
    ;; We need to remove the invisible property here.  Table narrowing
    ;; may have made some of this invisible.
    (org-remove-flyspell-overlays-in (match-beginning 0) (match-end 0))
    (remove-text-properties (match-beginning 0) (match-end 0)
                '(invisible nil))
    (if (match-end 3)
        (progn
          (add-text-properties (match-beginning 0) (match-beginning 3) ip)
          (org-rear-nonsticky-at (match-beginning 3))
          (add-text-properties (match-beginning 3) (match-end 3) vp)
          (org-rear-nonsticky-at (match-end 3))
          (add-text-properties (match-end 3) (match-end 0) ip)
          (org-rear-nonsticky-at (match-end 0)))
      (add-text-properties (match-beginning 0) (match-beginning 1) ip)
      (org-rear-nonsticky-at (match-beginning 1))
      (add-text-properties (match-beginning 1) (match-end 1) vp)
      (org-rear-nonsticky-at (match-end 1))
      (add-text-properties (match-end 1) (match-end 0) ip)
      (org-rear-nonsticky-at (match-end 0)))
    t)))

It searches for a match for a bracketed link (e.g. [[target][label]], hides the [[target][ part by adding ip to the text properties, then linkifies the label by adding vp to the text properties, and finally removes the trailing ]] by adding ip to the text properties again.

This all looks right. org-rear-nonsticky-at should take care of property bleeding.

This behaviour is triggered by (add-text-properties (match-end 3) (match-end 0) ip), which hides the trailing ]]. Only the 'invisible 'org-link property triggers this behaviour, the other properties appear to be innocent.

You could overwrite org-activate-bracket-links such that ip no longer sets 'invisible but 'display "", which has the same effect:

(defun org-activate-bracket-links (limit)
  "Run through the buffer and add overlays to bracketed links."
  (if (and (re-search-forward org-bracket-link-regexp limit t)
       (not (org-in-src-block-p)))
      (let* ((hl (org-match-string-no-properties 1))
         (help (concat "LINK: " (save-match-data (org-link-unescape hl))))
         (ip (org-maybe-intangible
          (list 'display ""
            'keymap org-mouse-map 'mouse-face 'highlight
            'font-lock-multiline t 'help-echo help
            'htmlize-link `(:uri ,hl))))
         (Vp (list 'keymap org-mouse-map 'mouse-face 'highlight
               'font-lock-multiline t 'help-echo help
               'htmlize-link `(:uri ,hl))))
    ;; We need to remove the invisible property here.  Table narrowing
    ;; may have made some of this invisible.
    (org-remove-flyspell-overlays-in (match-beginning 0) (match-end 0))
    (remove-text-properties (match-beginning 0) (match-end 0)
                '(invisible nil))
    (if (match-end 3)
        (progn
          (add-text-properties (match-beginning 0) (match-beginning 3) ip)
          (org-rear-nonsticky-at (match-beginning 3))
          (add-text-properties (match-beginning 3) (match-end 3) vp)
          (org-rear-nonsticky-at (match-end 3))
          (add-text-properties (match-end 3) (match-end 0) ip)
          (org-rear-nonsticky-at (match-end 0)))
      (add-text-properties (match-beginning 0) (match-beginning 1) ip)
      (org-rear-nonsticky-at (match-beginning 1))
      (add-text-properties (match-beginning 1) (match-end 1) vp)
      (org-rear-nonsticky-at (match-end 1))
      (add-text-properties (match-end 1) (match-end 0) ip)
      (org-rear-nonsticky-at (match-end 0)))
    t)))

Clearly, this is an ugly hack. But it works for me and might work for you. I still recommend filing a bug report.