missing a character / font in agenda?

missing a character / font in agenda?

[Daniel Ortmann]

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Hello,

During the past couple of weeks I have been seeing a new character in 
the agenda when the log is on and I am displaying the time grid. I have 
tried to find and install this character representation on Fedora-based 
Linux but have not found the magic.

Any clues where this particular symbol resides?  A hint about the 
package name would wonderful.  :-)

Thank you!




More information on that character:

              position: 195 of 690 (28%), column: 26
             character: ⭠ (displayed as ⭠) (codepoint 11104, #o25540, 
#x2b60)
               charset: unicode-bmp (Unicode Basic Multilingual Plane 
(U+0000..U+FFFF))
code point in charset: 0x2B60
                script: symbol
                syntax: _     which means: symbol
              category: .:Base
              to input: type "C-x 8 RET 2b60" or "C-x 8 RET LEFTWARDS 
TRIANGLE-HEADED ARROW"
           buffer code: #xE2 #xAD #xA0
             file code: #xE2 #xAD #xA0 (encoded by coding system utf-8-unix)
               display: no font available

Character code properties: customize what to show
   name: LEFTWARDS TRIANGLE-HEADED ARROW
   general-category: So (Symbol, Other)
   decomposition: (11104) ('⭠')

There are text properties here:
   breadcrumbs          nil
   day                  738348
   dotime               "12:11 "
   duration             nil
   extra                ""
   face                 org-agenda-current-time
   format               [Show]
   level                ""
   org-agenda-type      agenda
   org-category         ""
   org-day-cnt          1
   org-heading          t
   org-last-args        (nil 738348 day)
   org-priority-highest 65
   org-priority-lowest  67
   org-redo-cmd         (org-agenda-list 'nil 738348 'day nil)
   org-series-cmd       nil
   tags                 nil
   time                 "12:11 ┄┄┄┄┄ "
   time-of-day          1211
   txt                  [Show]

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Re: missing a character / font in agenda?

[Juan Manuel Macías]

Hi,

Daniel Ortmann writes:

> Any clues where this particular symbol resides?  A hint about the
> package name would wonderful.  :-)

To be able to display "unusual" symbols in Emacs, I usually use the
symbola font:

You can download it here:

https://fontlibrary.org/en/font/symbola

And then:

(set-fontset-font t 'symbol (font-spec :family "Symbola"))

But I think that what is interesting here is to know how that character
has arrived. Could it be related to some new package you have installed
lately?

Best regards,

Juan Manuel

Re: [External] : Re: missing a character / font in agenda?

[Daniel Ortmann]

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That odd new character just showed up after a normal daily org-mode 'git 
pull'.

The Symbola.ttf font worked fine.
I used this page for for instructions.
https://linuxconfig.org/how-to-install-and-manage-fonts-on-linux

After copying the font to ~/.local/share/font/ and running the 'fc-cache 
-vf' command
... The font appears after emacs + org-mode are restarted.
(I did not need to run set-fontset-font.)

Somewhere in there I also pulled fresh org-mode and emacs code and 
rebuilt; am not sure if that was needed.

Here is how that screen now appears:



  * Would using the ASCII '<' character be a better solution?
  * Is anyone else seeing this issue and missing font?
  * What would allow that Symbola font to be available?
  * Is that Symbola font, or equivalent, now a true dependency? Or is
    there something more common which I should be using? (Perhaps I have
    missed a normal configuration step?)

Thank you!


On 7/12/22 12:58, Juan Manuel Macías wrote:
> Hi,
>
> Daniel Ortmann writes:
>
>> Any clues where this particular symbol resides?  A hint about the
>> package name would wonderful.  :-)
> To be able to display "unusual" symbols in Emacs, I usually use the
> symbola font:
>
> You can download it here:
>
> https://urldefense.com/v3/__https://fontlibrary.org/en/font/symbola__;!!ACWV5N9M2RV99hQ!LCWutd87ZOlNkSgFTjjR0zYsqhv6xP6ZBep63lyK7tIveH2MWiQ331YB8rJexEVU6gjcjT99EdYoJvFPvxABlZvT$  
>
> And then:
>
> (set-fontset-font t 'symbol (font-spec :family "Symbola"))
>
> But I think that what is interesting here is to know how that character
> has arrived. Could it be related to some new package you have installed
> lately?
>
> Best regards,
>
> Juan Manuel

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Re: [External] : Re: missing a character / font in agenda?

[Juan Manuel Macías]

Hi, Daniel,

Daniel Ortmann writes:

> – Would using the ASCII '<' character be a better solution?

I've done a quick test and a few very popular (and more or less
complete) fonts don't include a glyph for the LEFTWARDS TRIANGLE-HEADED
ARROW #2b60 character: DejavuSans, Iosevka, Hack Source Code Pro,
JuliaMono or Fira Code. It is a very rare symbol.

> – Is anyone else seeing this issue and missing font?

I haven't seen it, but I'm not using the Git version.

> – Is that Symbola font, or equivalent, now a true dependency?  Or is
>   there something more common which I should be using?  (Perhaps I
>   have missed a normal configuration step?)

I think Symbola should not be a dependency. I use this font just to be
able to display unusual symbols, especially on web pages when I browse
the web with eww-mode. The most reasonable thing would be to use a more
common symbol. But I'm still intrigued by the origin of that symbol...

Best regards,

Juan Manuel

Re: [External] : Re: missing a character / font in agenda?

[Juan Manuel Macías]

Juan Manuel Macías writes:

> The most reasonable thing would be to use a more
> common symbol. But I'm still intrigued by the origin of that symbol...

It seems that the culprit is in line 1592 of org-agenda.el

I think this should be considered a bug, since the glyph used (LEFTWARDS
TRIANGLE-HEADED ARROW / #2b60) is not present in most fonts.

Best regards,

Juan Manuel

Re: [External] : Re: missing a character / font in agenda?

[Daniel Ortmann]

Ihor,
What are your thoughts?

On 7/12/22 15:03, Juan Manuel Macías wrote:
> Juan Manuel Macías writes:
>
>> The most reasonable thing would be to use a more
>> common symbol. But I'm still intrigued by the origin of that symbol...
> It seems that the culprit is in line 1592 of org-agenda.el
>
> I think this should be considered a bug, since the glyph used (LEFTWARDS
> TRIANGLE-HEADED ARROW / #2b60) is not present in most fonts.
>
> Best regards,
>
> Juan Manuel

Re: [External] : Re: missing a character / font in agenda?

[Ihor Radchenko]

Daniel Ortmann <daniel.ortmann@oracle.com> writes:

> Ihor,
> What are your thoughts?
>
> On 7/12/22 15:03, Juan Manuel Macías wrote:
>> Juan Manuel Macías writes:
>>
>>> The most reasonable thing would be to use a more
>>> common symbol. But I'm still intrigued by the origin of that symbol...
>> It seems that the culprit is in line 1592 of org-agenda.el
>>
>> I think this should be considered a bug, since the glyph used (LEFTWARDS
>> TRIANGLE-HEADED ARROW / #2b60) is not present in most fonts.

The offending commit is 998a0aacd from Stefan.
The commit is supposed to fall back to ASCII symbol if the Unicode
variant is not available, but apparently the check failed for some
reason:

(defcustom org-agenda-current-time-string
  (if (and (display-graphic-p)
           (char-displayable-p ?⭠)
           (char-displayable-p ?─))
      "⭠ now ───────────────────────────────────────────────"
    "now - - - - - - - - - - - - - - - - - - - - - - - - -")
  "The string for the current time marker in the agenda."
  :group 'org-agenda-time-grid
  :version "29.1"
  :type 'string)

Stefan, do you have any idea what can go wrong here?

The only thing I can think about is warning in the char-displayable-p
docstring:

>> On a multi-font display, the test is only whether there is an
>> appropriate font from the selected frame's fontset to display
>> CHAR's charset in general.  Since fonts may be specified on a
>> per-character basis, this may not be accurate.

Best,
Ihor

Re: [External] : Re: missing a character / font in agenda?

[Stefan Kangas]

Ihor Radchenko <yantar92@gmail.com> writes:

>>> I think this should be considered a bug, since the glyph used (LEFTWARDS
>>> TRIANGLE-HEADED ARROW / #2b60) is not present in most fonts.

If that is true (I don't know) then maybe we should just use a more
ubiquitous glyph?

> The commit is supposed to fall back to ASCII symbol if the Unicode
> variant is not available, but apparently the check failed for some
> reason:
[...]
> Stefan, do you have any idea what can go wrong here?
>
> The only thing I can think about is warning in the char-displayable-p
> docstring:
>
> >> On a multi-font display, the test is only whether there is an
> >> appropriate font from the selected frame's fontset to display
> >> CHAR's charset in general.  Since fonts may be specified on a
> >> per-character basis, this may not be accurate.

I don't think we specify a particular font here, do we?  So it seems
like there might be a bug in Emacs here?  I'm not an expert on this
stuff by any means, but I would probably 'M-x report-emacs-bug' to
find out why 'char-displayable-p' would say that a character is
displayable when it's not.

Re: [External] : Re: missing a character / font in agenda?

[Greg Minshall]

for what it's worth, without the symbola font on my machine (though i've
now added it), i seem to see the left-arrow 2b60 rendered using:
----
ftcrhb:-GNU-Unifont-normal-normal-normal-Sans-Serif-16-*-*-*-c-80-iso10646-1 (#x2B61)
----
(if i'm interpreting the output of [C-u C-x =] correctly.)

cheers, Greg

Re: [External] : Re: missing a character / font in agenda?

[Juan Manuel Macías]

Stefan Kangas writes:

> If that is true (I don't know) then maybe we should just use a more
> ubiquitous glyph?

I have done a quick test with some fonts that are ---I believe--- quite
popular. This character is missing from DejaVu Sans Mono, Iosevka,
Source Pro, Fira Code and Hack. JuliaMono does include it:

https://i.imgur.com/O3urnxa.png

I think LEFTWARDS ARROW / #2190 of the 'arrows' Unicode block is much
more common:

https://i.imgur.com/h0NQXvG.png

Best regards,

Juan Manuel 

Re: [External] : Re: missing a character / font in agenda?

[Max Nikulin]

On 13/07/2022 07:26, Stefan Kangas wrote:
> Ihor Radchenko writes:
> 
>>>> I think this should be considered a bug, since the glyph used (LEFTWARDS
>>>> TRIANGLE-HEADED ARROW / #2b60) is not present in most fonts.
> 
> If that is true (I don't know) then maybe we should just use a more
> ubiquitous glyph?

Disclaimer: I am not an expert in Unicode.

DejaVuSansMono has at least
- "\u{21fd}" "⇽" LEFTWARDS OPEN-HEADED ARROW 
https://util.unicode.org/UnicodeJsps/character.jsp?a=21fd
- "\u{2190}" "←" LEFTWARDS ARROW 
https://util.unicode.org/UnicodeJsps/character.jsp?a=2190
from https://en.wikipedia.org/wiki/Arrows_(Unicode_block)

Re: missing a character / font in agenda?

[Ihor Radchenko]

Daniel Ortmann <daniel.ortmann@oracle.com> writes:

> More information on that character:
>
>               position: 195 of 690 (28%), column: 26
>              character: ⭠ (displayed as ⭠) (codepoint 11104, #o25540, 
> #x2b60)
>                charset: unicode-bmp (Unicode Basic Multilingual Plane 
> (U+0000..U+FFFF))
> code point in charset: 0x2B60
>                 script: symbol
>                 syntax: _     which means: symbol
>               category: .:Base
>               to input: type "C-x 8 RET 2b60" or "C-x 8 RET LEFTWARDS 
> TRIANGLE-HEADED ARROW"
>            buffer code: #xE2 #xAD #xA0
>              file code: #xE2 #xAD #xA0 (encoded by coding system utf-8-unix)
>                display: no font available
>
> Character code properties: customize what to show
>    name: LEFTWARDS TRIANGLE-HEADED ARROW
>    general-category: So (Symbol, Other)
>    decomposition: (11104) ('⭠')

Would you mind sending a bug report to Emacs devs?
If you run (char-displayable-p ?⭠) on your side but yet not being able
to see the symbol properly, we can hopefully get some good suggestions
(or even a fix) from Emacs guys.

Best,
Ihor

Re: [External] : Re: missing a character / font in agenda?

[Ihor Radchenko]

Juan Manuel Macías <maciaschain@posteo.net> writes:

> I think LEFTWARDS ARROW / #2190 of the 'arrows' Unicode block is much
> more common:

Thanks for testing!
I now changed org-agenda to use LEFTWARDS ARROW in b4a72ddf9.

This does not completely solve the reported problem but at least less
users will suffer from it.

Best,
Ihor

Re: [External] : Re: missing a character / font in agenda?

[Daniel Ortmann]

I am not seeing the problem anymore after installing the Symbola fonts.

On 7/16/22 04:15, Ihor Radchenko wrote:
> Daniel Ortmann <daniel.ortmann@oracle.com> writes:
>
>> More information on that character:
>>
>>                position: 195 of 690 (28%), column: 26
>>               character: ⭠ (displayed as ⭠) (codepoint 11104, #o25540,
>> #x2b60)
>>                 charset: unicode-bmp (Unicode Basic Multilingual Plane
>> (U+0000..U+FFFF))
>> code point in charset: 0x2B60
>>                  script: symbol
>>                  syntax: _     which means: symbol
>>                category: .:Base
>>                to input: type "C-x 8 RET 2b60" or "C-x 8 RET LEFTWARDS
>> TRIANGLE-HEADED ARROW"
>>             buffer code: #xE2 #xAD #xA0
>>               file code: #xE2 #xAD #xA0 (encoded by coding system utf-8-unix)
>>                 display: no font available
>>
>> Character code properties: customize what to show
>>     name: LEFTWARDS TRIANGLE-HEADED ARROW
>>     general-category: So (Symbol, Other)
>>     decomposition: (11104) ('⭠')
> Would you mind sending a bug report to Emacs devs?
> If you run (char-displayable-p ?⭠) on your side but yet not being able
> to see the symbol properly, we can hopefully get some good suggestions
> (or even a fix) from Emacs guys.
>
> Best,
> Ihor

Re: [External] : Re: missing a character / font in agenda?

[Max Nikulin]

On 17/07/2022 15:58, Ihor Radchenko wrote:
> Juan Manuel Macías writes:
> 
>> I think LEFTWARDS ARROW / #2190 of the 'arrows' Unicode block is much
>> more common:
> 
> Thanks for testing!
> I now changed org-agenda to use LEFTWARDS ARROW in b4a72ddf9.
> 
> This does not completely solve the reported problem but at least less
> users will suffer from it.

At least in Noto Sans Mono (default font in Kubuntu, unsure concerning 
vanilla KDE) \u{2190} "←" arrow is below other dashes like - or —. 
Another symbol \u{21fd} "⇽" LEFTWARDS OPEN-HEADED ARROW from the same 
arrows Unicode block does not has such problem in this font.

Re: [External] : Re: missing a character / font in agenda?

[Ihor Radchenko]

Max Nikulin <manikulin@gmail.com> writes:

> DejaVuSansMono has at least
> - "\u{21fd}" "⇽" LEFTWARDS OPEN-HEADED ARROW 
> https://util.unicode.org/UnicodeJsps/character.jsp?a=21fd
> - "\u{2190}" "←" LEFTWARDS ARROW 
> https://util.unicode.org/UnicodeJsps/character.jsp?a=2190
> from https://en.wikipedia.org/wiki/Arrows_(Unicode_block)

"⇽" looks better on my system. However, I do not see "⇽" LEFTWARDS
OPEN-HEADED ARROW in Liberation Fonts used by default in Emacs on my
system. Though I only tested using emacs -Q + M-x describe-char

Best,
Ihor

Re: [External] : Re: missing a character / font in agenda?

[Max Nikulin]

On 05/08/2022 13:15, Ihor Radchenko wrote:
> Max Nikulin writes:
> 
>> DejaVuSansMono has at least
>> - "\u{21fd}" "⇽" LEFTWARDS OPEN-HEADED ARROW
>> https://util.unicode.org/UnicodeJsps/character.jsp?a=21fd
>> - "\u{2190}" "←" LEFTWARDS ARROW
>> https://util.unicode.org/UnicodeJsps/character.jsp?a=2190
>> from https://en.wikipedia.org/wiki/Arrows_(Unicode_block)
> 
> "⇽" looks better on my system. However, I do not see "⇽" LEFTWARDS
> OPEN-HEADED ARROW in Liberation Fonts used by default in Emacs on my
> system. Though I only tested using emacs -Q + M-x describe-char

You are right. Courier New is immortal and fonts created to be 
metric-compatible with it will outlive this font. I forgot about such 
compatibility test.

Another approach would be assuming reasonable set of modern fonts and 
providing some defcustom to switch to legacy compatibility mode.

Re: [External] : Re: missing a character / font in agenda?

[Ihor Radchenko]

Max Nikulin <manikulin@gmail.com> writes:

> Another approach would be assuming reasonable set of modern fonts and 
> providing some defcustom to switch to legacy compatibility mode.

This whole thread is about a single defcustom already.
I do not see much point providing yet another defcustom on top.
`char-displayable-p' check should be good enough in most cases, except
some strange font mapping settings. In the latter cases, users can
always customize org-agenda-current-time-string manually.

Ideally, we need to find a more reliable alternative to
`char-displayable-p'.

Best,
Ihor

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
Support Org development at https://liberapay.com/org-mode,
or support my work at https://liberapay.com/yantar92