bug#19225: eww-render: runs eww-after-render-hook in the (temporary) data buffer

[Ivan Shmakov]

Package:  emacs

>>>>> Lars Magne Ingebrigtsen <larsi@gnus.org> writes:
>>>>> Ivan Shmakov <ivan@siamics.net> writes:

[…]

 >> The plist-put calls down that progn are evaluated after
 >> eww-display-*, and thus after either eww-setup-buffer or some other
 >> set-buffer.  The eww-use-external-browser-for-content-type case I’m
 >> unsure about, though.

 > I've now removed the statement.

        Following the change for eww-display-* /not/ to change the
        current buffer ($ git log entry MIMEd), those forms are now also
        evaluated in the data buffer.

   283  (defun eww-render (status url &optional point buffer encode)
…
   287    (let* ((headers (eww-parse-headers))
…
   298           (data-buffer (current-buffer)))
   299      (unwind-protect
   300          (progn
…
   316            (plist-put eww-data :url url)
   317            (setq eww-history-position 0)
   318            (run-hooks 'eww-after-render-hook))
   319        (kill-buffer data-buffer))))

        What’s even worse is that the call to eww-after-render-hook is
        among them, and thus the code there has no (easy) way of finding
        the EWW buffer proper; consider, e. g.:

(add-hook 'eww-after-render-hook
          (lambda () (message "Called in: %S" (current-buffer))))

Called in: #<buffer  *http my.proxy.example:3128*>

        There’re two obvious ways to deal with the issues with eww-data
        and eww-history-position:

        • they could be wrapped into a (with-current-buffer buffer …)
          form in eww-render;

        • or they could be moved from there to eww-display-raw, -image,
          and -pdf; (eww-display-html already has them.)

        The eww-after-render-hook case is a bit trickier, as I’d rather
        prefer having some easy way to access /either/ of the buffers
        from the functions referenced.  For instance, I’d like to have a
        way to capture the HTTP header and provide a command to present
        it to the user when asked.  (I doubt this feature really belongs
        to the EWW “core,” so doing it from the hook looks sensible.)

-- 
FSF associate member #7257  http://boycottsystemd.org/  … 3013 B6A0 230E 334A

commit 6fd82d61a2b82e772e8cde0e04516f5c3ca98ed3
Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
Date:   Sun Nov 23 17:22:41 2014 +0100

    Switch to the *eww* buffer immediately to avoid doing it asynchronously
    
    (eww): Pop to the *eww* buffer immediately after executing the
    `M-x eww' command to avoid having buffers pop up later.
    (eww-display-html): Don't pop the *eww* buffer.
    (eww-display-raw): Ditto.
    (eww-display-image): Ditto.