Re: How to enforce unicode font for all charsets?

[Sergey Organov <sorganov@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Sergey Organov <sorganov@gmail.com>
>> Cc: help-gnu-emacs@gnu.org
>> Date: Fri, 13 Mar 2020 09:48:11 +0300
>> 
>> (let ((buf (get-buffer-create "test encodings")))
>>   (with-current-buffer buf
>>     (erase-buffer)
>>     (insert "Encoding windows-1251: "
>>             (propertize "привет\n" 'charset 'windows-1251))
>>     (insert "Encoding      unicode: "
>>             (propertize "привет\n" 'charset 'unicode)))
>>   (switch-to-buffer-other-window buf))
>> 
>> What I see in "emacs -Q" is attached as Emacs window snapshot. Please
>> notice how two strings look very different where encodings differ. What
>> I see in my "regular" Emacs is almost the same, just in larger font
>> size.
>> 
>> The question is why Emacs doesn't use the default font for windows-1251
>> encoding when the font definitely has all the needed glyphs?
>
> Thanks for the recipe.  Please go to each "привет" in the test buffer
> and type "C-u C-x =", then show what the *Help* buffer displays for
> each of the two.

Here are the results:

--- >8 ---
             position: 24 of 60 (38%), column: 23
            character: п (displayed as п) (codepoint 1087, #o2077, #x43f)
    preferred charset: windows-1251 (WINDOWS-1251 (Cyrillic))
code point in charset: 0xEF
               script: cyrillic
               syntax: w 	which means: word
             category: .:Base, L:Left-to-right (strong), Y:2-byte Cyrillic, c:Chinese, h:Korean, j:Japanese, y:Cyrillic
             to input: type "C-x 8 RET 43f" or "C-x 8 RET CYRILLIC SMALL LETTER PE"
          buffer code: #xD0 #xBF
            file code: #xD0 #xBF (encoded by coding system utf-8-unix)
              display: by this font (glyph code)
    x:-xos4-terminus-medium-r-normal--16-160-72-72-c-80-microsoft-cp1251 (#xEF)

Character code properties: customize what to show
  name: CYRILLIC SMALL LETTER PE
  general-category: Ll (Letter, Lowercase)
  decomposition: (1087) ('п')

There are text properties here:
  charset              windows-1251
--- >8 ---
             position: 54 of 60 (88%), column: 23
            character: п (displayed as п) (codepoint 1087, #o2077, #x43f)
    preferred charset: unicode (Unicode (ISO10646))
code point in charset: 0x043F
               script: cyrillic
               syntax: w 	which means: word
             category: .:Base, L:Left-to-right (strong), Y:2-byte Cyrillic, c:Chinese, h:Korean, j:Japanese, y:Cyrillic
             to input: type "C-x 8 RET 43f" or "C-x 8 RET CYRILLIC SMALL LETTER PE"
          buffer code: #xD0 #xBF
            file code: #xD0 #xBF (encoded by coding system utf-8-unix)
              display: by this font (glyph code)
    xft:-PfEd-DejaVu Sans Mono-normal-normal-normal-*-15-*-*-*-m-0-iso10646-1 (#x37E)

Character code properties: customize what to show
  name: CYRILLIC SMALL LETTER PE
  general-category: Ll (Letter, Lowercase)
  decomposition: (1087) ('п')

There are text properties here:
  charset              unicode
--- >8 ---

> FWIW, I cannot reproduce this on my system: I see the same font being
> used in both cases.  But maybe this is system-dependent in some ways,
> or maybe the fonts you have installed affect this.  So I think you
> should report all this (including the information I requested above)
> as part of a bug report, using "M-x report-emacs-bug", and let's take
> it from there.

Please confirm I need to report a bug based on the above information.

-- Sergey