math, png: TeX for Gmail, not shown in GNU Emacs.

math, png: TeX for Gmail, not shown in GNU Emacs.

[Uwe Brauer]

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Hello

I asked something similar 1 year ago but meanwhile I have (at least
partially) switched from Xemacs 21.5.34 mule to GNU Emacs 25, using
ma-gnus 0.9. The problem I am to describe was not solvable for Xemacs
but I seem to remember that it was for GNU Emacs. However right now for
my current setting the display of the messages in question is not correct.

Situation:

I receive html-email generated by gmail using the «TeX for Gmail»
extension, which like latexit for thunderbird, or org-mime-htmlize for
Emacs converts latex formula to png. Actually I receive a lot of them
and their correct display is important for me.

However while this message is displayed correctly in 

    -  gmail itself using firefox, 

    -  thunderbird, 

    - it is not so (any longer, at least not in my setting) for GNU
      Emacs.

I use mm-text-html-renderer 'gnus-w3m
and played around with
  (setq gnus-mime-display-multipart-related-as-mixed nil)
  (setq gnus-mime-display-multipart-as-mixed nil)

Or   set to t.

I attach 4 screen shots
1. Firefox+gmail
2. Thunderbird
3. GNU Emacs with gnus-mime-display-multipart-as-mixed nil
4. GNU Emacs with gnus-mime-display-multipart-as-mixed t

I recall that somebody on the list told me he could see such embedded
png. I would love to hear about it and which setting I have to use.


Thanks very much

Uwe Brauer


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Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Adam Sjøgren]

Uwe writes:

> I receive html-email generated by gmail using the «TeX for Gmail»
> extension, which like latexit for thunderbird, or org-mime-htmlize for
> Emacs converts latex formula to png.

Do you by any chance have any of these variables set to not show HTML:

  mm-discouraged-alternatives
  mm-automatic-display

?

Have you tried using shr as the HTML renderer? I.e. leaving
mm-text-html-renderer at its default value?

Have you customized mm-automatic-display?

What have you set mm-inline-text-html-with-images to?

And if you keep using w3m, what is mm-w3m-safe-url-regexp set to?


Those are the variables I have touched in my config; maybe one if the
holds the key.


  :-),

   Adam

-- 
 "We're not unreasonable, I mean, noone's going to eat        Adam Sjøgren
  your eyes"                                             asjo@koldfront.dk

Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Uwe Brauer]

>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:
Hi

I remember now it was you who said you could see those png!

   > Uwe writes:
   >> I receive html-email generated by gmail using the «TeX for Gmail»
   >> extension, which like latexit for thunderbird, or org-mime-htmlize for
   >> Emacs converts latex formula to png.

   > Do you by any chance have any of these variables set to not show HTML:

   >   mm-discouraged-alternatives


Set to nil
   >   mm-automatic-display
mm-automatic-display is a variable defined in ‘mm-decode.el’. Its value
is ("text/calendar" "text/plain" "text/enriched" "text/richtext"
"text/html" "text/x-verbatim" "text/x-vcard" "image/.*"
"message/delivery-status" "multipart/.*" "message/rfc822" "text/x-patch"
"text/dns" "application/pgp-signature" "application/emacs-lisp"
"application/x-emacs-lisp" "application/x-pkcs7-signature"
"application/pkcs7-signature" "application/x-pkcs7-mime"
"application/pkcs7-mime" "application/pgp\\'" "text/x-org")

   > ?

   > Have you tried using shr as the HTML renderer? I.e. leaving
   > mm-text-html-renderer at its default value?

Yes no difference
   > Have you customized mm-automatic-display?

See above

   > What have you set mm-inline-text-html-with-images to?

This is nil, custom tells me just to toggle them on

   > And if you keep using w3m, what is mm-w3m-safe-url-regexp set to?

m-w3m-safe-url-regexp is a variable defined in ‘mm-decode.el’.
Its value is "\\`cid:"

   > Those are the variables I have touched in my config; maybe one if the
   > holds the key.

Could you please send me your setting of this variable?

Thanks

Uwe 

Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Uwe Brauer]

   > Those are the variables I have touched in my config; maybe one if the
   > holds the key.
BTW what is your setting of
 gnus-mime-display-multipart-related-as-mixed 
 gnus-mime-display-multipart-as-mixed 

Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Adam Sjøgren]

Uwe writes:

>> What have you set mm-inline-text-html-with-images to?

> This is nil, custom tells me just to toggle them on

So, isn't that the culprit?

,----[ C-h v mm-inline-text-html-with-images RET ]
| mm-inline-text-html-with-images is a variable defined in `mm-decode.el'.
| Its value is t
| Original value was nil
| 
| Documentation:
| If non-nil, Gnus will allow retrieving images in HTML that has <img> tags.
| See also the documentation for the `mm-w3m-safe-url-regexp'
| variable.
`----

I would try setting that to t and use shr as the renderer.

>> And if you keep using w3m, what is mm-w3m-safe-url-regexp set to?

> m-w3m-safe-url-regexp is a variable defined in ‘mm-decode.el’.
> Its value is "\\`cid:"

I've set it to nil (because I've also discouraged text/html display, and
thus actively have to choose to show HTML-parts).

,----[ C-h v mm-w3m-safe-url-regexp RET ]
| mm-w3m-safe-url-regexp is a variable defined in `mm-decode.el'.
| Its value is nil
| Original value was "\\`cid:"
| 
| Documentation:
| Regexp matching URLs which are considered to be safe.
| Some HTML mails might contain a nasty trick used by spammers, using
| the <img> tag which is far more evil than the [Click Here!] button.
| It is most likely intended to check whether the ominous spam mail has
| reached your eyes or not, in which case the spammer knows for sure
| that your email address is valid.  It is done by embedding an
| identifier string into a URL that you might automatically retrieve
| when displaying the image.  The default value is "\\`cid:" which only
| matches parts embedded to the Multipart/Related type MIME contents and
| Gnus will never connect to the spammer's site arbitrarily.  You may
| set this variable to nil if you consider all urls to be safe.
`----

Are the images in your emails inline or linked?

>> Those are the variables I have touched in my config; maybe one if the
>> holds the key.

> Could you please send me your setting of this variable?

We don't know that my setup shows the images, as you haven't provided
anything to test on.


  Best regards,

    Adam

-- 
 "Halleluja og hurlumhej"                                     Adam Sjøgren
                                                         asjo@koldfront.dk

Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Uwe Brauer]

>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

   > We don't know that my setup shows the images, as you haven't provided
   > anything to test on.

Ok can I send you privately such an email and you tell me whether you
see the images?

I don't want to bother the list with html mail.

Uwe 

Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Adam Sjøgren]

Uwe writes:

> Ok can I send you privately such an email and you tell me whether you
> see the images?

Now that I have an example, I can see that your email contains links to
external images that need to be fetched by http. I wonder what you have
gnus-blocked-images set to?

If I set it to nil, Gnus/shr fetches the images from latex.codecogs.com
and displays them.

,----[ C-h v gnus-blocked-images RET ]
| gnus-blocked-images is a variable defined in `gnus-art.el'.
| Its value is nil
| Original value was 
| gnus-block-private-groups
| 
| Documentation:
| Images that have URLs matching this regexp will be blocked.
| This can also be a function to be evaluated.  If so, it will be
| called with the group name as the parameter, and should return a
| regexp.
`----


  Best regards,

    Adam

-- 
 "parsley, sage, rosemary and KOMPRESSOR"                     Adam Sjøgren
                                                         asjo@koldfront.dk

Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Uwe Brauer]

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>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

   > Uwe writes:
   >> Ok can I send you privately such an email and you tell me whether you
   >> see the images?

   > Now that I have an example, I can see that your email contains links to
   > external images that need to be fetched by http. I wonder what you have
   > gnus-blocked-images set to?

   > If I set it to nil, Gnus/shr fetches the images from latex.codecogs.com
   > and displays them.

That was the culprit!!! Thanks.

BTW the images are very big, also for your? I attach a screenshot


Thanks again, this has been very helpful.



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Re: math, png: TeX for Gmail, not shown in GNU Emacs.

[Adam Sjøgren]

Uwe writes:

> BTW the images are very big, also for your? I attach a screenshot

I guess latex.codecogs.com sends big images? They look like that in my
Gnus as well.


  Best regards,

    Adam

-- 
 "I'm a driver, I'm a winner, things are gonna change,        Adam Sjøgren
  I can feel it."                                        asjo@koldfront.dk

[Xemacs] (was: math, png: TeX for Gmail, not shown in GNU Emacs.)

[Uwe Brauer]

>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

> Uwe writes:
>> BTW the images are very big, also for your? I attach a screenshot

> I guess latex.codecogs.com sends big images? They look like that in my
> Gnus as well.
Ok, there seems nothing one can do about it, since the formulas look ok
in any browswer I tested: firefox/chrome/seamonkey.

BTW the formulas are not displayed, with the same setting, in Xemacs. I
will submit a bug report but don't make myself to many illusions (sigh
Xemacs...) 

[stoped working] (was: math, png: TeX for Gmail, not shown in GNU Emacs.)

[Uwe Brauer]

>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

> Uwe writes:
>> Ok can I send you privately such an email and you tell me whether you
>> see the images?

> Now that I have an example, I can see that your email contains links to
> external images that need to be fetched by http. I wonder what you have
> gnus-blocked-images set to?

You are not going to believe that but the feature stopped working. With
the same setting as yesterday the images are not longer fetched.

(setq gnus-inhibit-mime-unbuttonizing nil) 
(setq
 mm-discouraged-alternatives nil
 gnus-buttonized-mime-types '("multipart/signed" "multipart/encrypted")
; mm-automatic-display (remove "text/html" mm-automatic-display)
 ;; Render HTML with w3m
;;mm-text-html-renderer 'gnus-w3m
;;mm-text-html-renderer 'shr
mm-text-html-renderer 'gnus-article-html
 mm-url-use-external t)
 
(setq w3m-safe-url-regexp nil)
(setq  gnus-blocked-images nil)
(setq  mm-inline-text-html-with-images t)



In xemacs they are fetched but not displayed.

Re: [Xemacs]

[Adam Sjøgren]

Uwe writes:

>>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

>> I guess latex.codecogs.com sends big images? They look like that in my
>> Gnus as well.

> Ok, there seems nothing one can do about it, since the formulas look ok
> in any browswer I tested: firefox/chrome/seamonkey.

Not besides hacking Emacs to scale them.

> BTW the formulas are not displayed, with the same setting, in Xemacs. I
> will submit a bug report but don't make myself to many illusions (sigh
> Xemacs...) 

I gave up a couple of years ago.


  Best regards,

    Adam

-- 
 "I'm a driver, I'm a winner, things are gonna change,        Adam Sjøgren
  I can feel it."                                        asjo@koldfront.dk

Re: [stoped working]

[Adam Sjøgren]

Uwe writes:

> You are not going to believe that but the feature stopped working. With
> the same setting as yesterday the images are not longer fetched.

Well, then the webserver in the other end (latex.codecogs.com) returns:

  HTTP/1.1 500 Internal Server Error.
  Content-Type: text/html.
  Content-Length: 369.
  Date: Sun, 13 Sep 2015 11:43:58 GMT.
  Server: lighttpd/1.4.36.
  .
  <?xml version="1.0" encoding="iso-8859-1"?>
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
           "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
   <head>
    <title>500 - Internal Server Error</title>
   </head>
   <body>
    <h1>500 - Internal Server Error</h1>
   </body>
  </html>

It _is_ kind of hard for Gnus to display the images.

That is the downside of relying on a third party to provide images.

> In xemacs they are fetched but not displayed.

I don't know how you concluded that, but I doubt it.


  Best regards,

    Adam

-- 
 "Everybody will be quick to agree that EMACS has a           Adam Sjøgren
  simple to learn user interface, at least to gain       asjo@koldfront.dk
  'novice' status."

Re: [stoped working]

[Uwe Brauer]

>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

   > Uwe writes:
   >> You are not going to believe that but the feature stopped working. With
   >> the same setting as yesterday the images are not longer fetched.

   > Well, then the webserver in the other end (latex.codecogs.com) returns:

   >   HTTP/1.1 500 Internal Server Error.
   >   Content-Type: text/html.
   >   Content-Length: 369.
   >   Date: Sun, 13 Sep 2015 11:43:58 GMT.
   >   Server: lighttpd/1.4.36.
   >   .
   >   <?xml version="1.0" encoding="iso-8859-1"?>
   >   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
   >            "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
   >   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
   >    <head>
   >     <title>500 - Internal Server Error</title>
   >    </head>
   >    <body>
   >     <h1>500 - Internal Server Error</h1>
   >    </body>
   >   </html>

   > It _is_ kind of hard for Gnus to display the images.

How do you see this messages?

   > That is the downside of relying on a third party to provide images.

But why are displayed in seamonkey/firefox/chrome correctly? 

   >> In xemacs they are fetched but not displayed.



   > I don't know how you concluded that, but I doubt it.

Well I see 

--8<---------------cut here---------------start------------->8---
Stored: Email from Uwe Brauer: To: UWE RICHARD OTTO Brauer: Date: Sun,
13 Sep 2015 11:16:58 +0200 Subj:   
Retrieval complete.
Reading... 535 bytes.
Contacting latex.codecogs.com:80

tex Actually we have the following situation:
<pre_int>H_1\subse</pre_int><_id id="l0.06521869946887593"> are  Hilbert
spaces, a map <pre_int><img_alt
src="http://latex.codecogs.com/gif.latex?%5Cdpi%7B300%7D%5Cinline%09%5CPhi:H%5F1%5Cto%09H%5F1"
width="91" height="14" hseq="2" title="\Phi:H_1\to H_1">\Phi:H_1\to
H</img_alt></pre_int><_id id="l0.3265760676902906"> and we set
<pre_int><img_alt
src="http://latex.codecogs.com/gif.latex?%5Cdpi%7B300%7D%5Cinline%09x%5F{n%2B1}=%5CPhi(x%5Fn)"
width="98" height="16" hseq="3" yoffset="-1"
title="x_{n+1}=\Phi(x_n)">x_{n+1}=\Phi(x</img_alt></pre_int><_id
id="l0.17770456394407674">. Then by the energy estimates we have:

--8<---------------cut here---------------end--------------->8---

Thanks 

Uwe 

Re: [stoped working]

[Uwe Brauer]

[-- Attachment #1: Type: text/plain, Size: 1103 bytes --]

>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

> Uwe writes:
>> You are not going to believe that but the feature stopped working. With
>> the same setting as yesterday the images are not longer fetched.

> Well, then the webserver in the other end (latex.codecogs.com) returns:

>   HTTP/1.1 500 Internal Server Error.
>   Content-Type: text/html.
>   Content-Length: 369.
>   Date: Sun, 13 Sep 2015 11:43:58 GMT.
>   Server: lighttpd/1.4.36.
>   .
>   <?xml version="1.0" encoding="iso-8859-1"?>
>   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
>            "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
>   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
>    <head>
>     <title>500 - Internal Server Error</title>
>    </head>
>    <body>
>     <h1>500 - Internal Server Error</h1>
>    </body>
>   </html>

> It _is_ kind of hard for Gnus to display the images.

Now I found the following buffer _*mm-482677
who displays the information about the gifs (but Emacs does not display
them) so I conclude the server is right now not down?

[-- Attachment #2: mm-482677 --]
[-- Type: text/plain, Size: 2091 bytes --]

<div dir=3D"ltr">=C2=A0 Actually we have the following situation: <img id=
=3D"l0.06521869946887593" src=3D"http://latex.codecogs.com/gif.latex?%5Cdpi=
%7B300%7D%5Cinline%09H%5F1%5Csubset%09H%5F2" class=3D"va_li" style=3D"displ=
ay: inline; vertical-align: -2.567px;" title=3D"H_1\subset H_2" alt=3D"H_1\=
subset H_2" height=3D"14" width=3D"62"> are<br>=C2=A0Hilbert spaces, a map =
<img id=3D"l0.3265760676902906" src=3D"http://latex.codecogs.com/gif.latex?=
%5Cdpi%7B300%7D%5Cinline%09%5CPhi:H%5F1%5Cto%09H%5F1" class=3D"va_li" style=
=3D"display: inline; vertical-align: -2.567px;" title=3D"\Phi:H_1\to H_1" a=
lt=3D"\Phi:H_1\to H_1" height=3D"14" width=3D"91"> and we set <img id=3D"l0=
.17770456394407674" src=3D"http://latex.codecogs.com/gif.latex?%5Cdpi%7B300=
%7D%5Cinline%09x%5F{n%2B1}=3D%5CPhi(x%5Fn)" class=3D"va_li" style=3D"displa=
y: inline; vertical-align: -3.667px;" title=3D"x_{n+1}=3D\Phi(x_n)" alt=3D"=
x_{n+1}=3D\Phi(x_n)" height=3D"16" width=3D"98">. Then by the energy estima=
tes we have:<br>=C2=A0 1. <img id=3D"l0.48052587598745655" src=3D"http://la=
tex.codecogs.com/gif.latex?%5Cdpi%7B300%7D%5Cinline%09%5C{x%5Fn%5C}" class=
=3D"va_li" style=3D"display: inline; vertical-align: -4.034px;" title=3D"\{=
x_n\}" alt=3D"\{x_n\}" height=3D"16" width=3D"32"> is bounded in <img id=3D=
"l0.15070800685165398" src=3D"http://latex.codecogs.com/gif.latex?%5Cdpi%7B=
300%7D%5Cinline%09H%5F1" class=3D"va_li" style=3D"display: inline; vertical=
-align: -2.567px;" title=3D"H_1" alt=3D"H_1" height=3D"14" width=3D"19">;<b=
r>=C2=A0 2. <img id=3D"l0.17361696536987203" src=3D"http://latex.codecogs.c=
om/gif.latex?%5Cdpi%7B300%7D%5Cinline%09%5C{x%5Fn%5C}" class=3D"va_li" styl=
e=3D"display: inline; vertical-align: -4.034px;" title=3D"\{x_n\}" alt=3D"\=
{x_n\}" height=3D"16" width=3D"32"> is Cauchy in <img id=3D"l0.219514490323=
2813" src=3D"http://latex.codecogs.com/gif.latex?%5Cdpi%7B300%7D%5Cinline%0=
9H%5F2" class=3D"va_li" style=3D"display: inline; vertical-align: -2.2px;" =
title=3D"H_2" alt=3D"H_2" height=3D"13" width=3D"19"> (by the contraction).=
<br><br></div>

Re: [stoped working]

[Adam Sjøgren]

Uwe writes:

> How do you see this messages?

I use ngrep(8) to watch the network traffic while displaying the HTML
email in Gnus.

You could use tcpdump(8), wireshark(1), or whatever your favourite
network monitoring tool is.

>> That is the downside of relying on a third party to provide images.

> But why are displayed in seamonkey/firefox/chrome correctly? 

I don't know. "500 - Internal Server Error" is not very enlightening.
Try asking whomever runs latex.codecogs.com.

Oh, I just got a 500 Internal Server Error fetching one of the gifs in
Iceweasel, so I think latex.codecogs.com is just flaky:

 * http://koldfront.dk/misc/500latexcodecogs.png

>>> In xemacs they are fetched but not displayed.

>> I don't know how you concluded that, but I doubt it.

> Well I see 

> Stored: Email from Uwe Brauer: To: UWE RICHARD OTTO Brauer: Date: Sun,
> 13 Sep 2015 11:16:58 +0200 Subj:   
> Retrieval complete.
> Reading... 535 bytes.
> Contacting latex.codecogs.com:80

And you are sure that 535 bytes is not the size of the Internal Server
Error response?


  Best regards,

    Adam

-- 
 "Det er Thomas Treo, han kan _kun_ lide Sort Sol."           Adam Sjøgren
                                                         asjo@koldfront.dk

Re: [stoped working]

[Adam Sjøgren]

Uwe writes:

> Now I found the following buffer _*mm-482677
> who displays the information about the gifs (but Emacs does not display
> them) so I conclude the server is right now not down?

How do you get to that conclusion?

The mumbo-jumbo you cite is the HTML in the email - that says NOTHING
about whether latex.codecogs.com is working or not.

You have to follow the img-links to to see if you get an image or an
error page.

I get an error page in Iceweasel right now. A little earlier today I got
images.

So my conclusion is that there probably is a problem at
latex.codecogs.com and probably not in Emacs/Gnus.


  Best regards,

    Adam

-- 
 "'What-you-see-is-what-you-get' is Motherhood and            Adam Sjøgren
  Apple Pie for screen editors, and EMACS definitely     asjo@koldfront.dk
  succeeds here."

Re: [stoped working]

[Adam Sjøgren]

Adam writes:

> So my conclusion is that there probably is a problem at
> latex.codecogs.com and probably not in Emacs/Gnus.

Further evidence: If you go to http://latex.codecogs.com/ the image in
the example is broken currently.


  Best regards,

    Adam

-- 
 "I think geniuses should be given special                    Adam Sjøgren
  considerations."                                       asjo@koldfront.dk

Re: [stoped working]

[Uwe Brauer]

>>>>> "Adam" == Adam Sjøgren <asjo@koldfront.dk> writes:

   > Adam writes:
   >> So my conclusion is that there probably is a problem at
   >> latex.codecogs.com and probably not in Emacs/Gnus.

   > Further evidence: If you go to http://latex.codecogs.com/ the image in
   > the example is broken currently.

Right, this seems hopeless.

   >   Best regards,

   >     Adam