From: Aaron Ecay <aaronecay@gmail.com>
To: David Edmondson <dme@dme.org>, notmuch@notmuchmail.org
Subject: Re: [RFC][PATCH] emacs: Provide scaffolding so that the new `shr'
	HTML renderer can run.
In-Reply-To: <1324309559-7993-1-git-send-email-dme@dme.org>
References: <1324309559-7993-1-git-send-email-dme@dme.org>
User-Agent: Notmuch/0.10.1+56~gd709fd6 (http://notmuchmail.org)
	Emacs/24.0.92.3 (i386-apple-darwin10.8.0)
Date: Mon, 19 Dec 2011 12:50:17 -0500
Message-ID: <m2bor4mox2.fsf@gmail.com>
MIME-Version: 1.0
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Precedence: list

David,

This patch doesn=E2=80=99t allow users to have their own settings for
shr-{inhibit,block}-images, since it forces these values to nil (via the
corresponding gnus variables).

(For those looking to follow the code, here=E2=80=99s the call path:
notmuch-show-mm-display-part-inline ->
mm-display-part ->
mm-display-inline -> (via lookup table)
mm-inline-text-html -> (via LUT)
mm-shr
The last function is where this objectionable rebinding happens)

Would a better approach be:
- clone the mm-shr function, replacing the vile gnus-specific code with
  something functionally similar that takes the values from notmuch-foo
  variables instead
- add '(notmuch-shr . notmuch-mm-shr) to the mm-text-html-renderer-alist
  variable
- tell notmuch users to customize mm-text-html-renderer to 'notmuch-shr
  if they want to use this renderer

The default values of the notmuch-{inhibit,block}-images variables
should prevent network requests for images being made by default* =E2=80=93=
 your
proposed nil/nil values don=E2=80=99t do this, AFAICT.  Not doing network
requests for HTML email has been Spam Mitigation/Identity Protection 101
for a long time;** notmuch=E2=80=99s default behavior in this area has alwa=
ys
bothered me.

(Also, while we are on the subject of wonky defaults, why is
notmuch-show-all-multipart/alternative-parts set to t by default?  This
is certainly not the best setting.)

FWIW, the patch does seem to allow using shr as the HTML renderer, but
for the reasons expressed I don=E2=80=99t think it solves the broader probl=
em.

Aaron

* I think that inhibit -> nil, block -> ".*" should achieve this, but I=E2=
=80=99m
  not sure/haven=E2=80=99t tested

** For example, Gmail makes you click a link at the top of an email
   before it will load any network images contained therein.

--=20
Aaron Ecay