bug#24772: 26.0.50; homoglyph face is used in Gnus, eww

[Óscar Fuentes]

The new homoglyph face introduced in
c06a518b5b0706509252abb03875867b10a92fc7 is being used for displaying
characters in Gnu and eww buffers. Those characters look like sore
thumbs, very displeasing.

I have no idea why the curly things are being replaced. I'm using a
graphics terminal (X on GNU/Linux). This is describe-char from a eww
buffer:

             position: 426 of 6337 (7%), column: 143
            character: ‘ (displayed as ‘) (codepoint 8216, #o20030, #x2018)
    preferred charset: unicode (Unicode (ISO10646))
code point in charset: 0x2018
               script: symbol
               syntax: .        which means: punctuation
             category: .:Base, <:Not at eol, c:Chinese, h:Korean, j:Japanese
             to input: type "C-x 8 RET 2018" or "C-x 8 RET LEFT SINGLE 
QUOTATION MARK"
          buffer code: #xE2 #x80 #x98
            file code: #xE2 #x80 #x98 (encoded by coding system raw-text-unix)
              display: by display table entry [?`] (see below)

The display table entry is displayed by these fonts (glyph codes):
`: xft:-PfEd-DejaVu Sans-normal-normal-normal-*-19-*-*-*-*-0-iso10646-1 (#x43)
 face: ‘homoglyph’

Character code properties: customize what to show
  name: LEFT SINGLE QUOTATION MARK
  old-name: SINGLE TURNED COMMA QUOTATION MARK
  general-category: Pi (Punctuation, Initial quote)
  decomposition: (8216) ('‘')

There are text properties here:
  face                 variable-pitch


Another one, with a different font, from a Gnus Summary buffer:

             position: 1484 of 13282 (11%), column: 35
            character: “ (displayed as “) (codepoint 8220, #o20034, #x201c)
    preferred charset: unicode (Unicode (ISO10646))
code point in charset: 0x201C
               script: symbol
               syntax: .        which means: punctuation
             category: .:Base, <:Not at eol, c:Chinese, h:Korean, j:Japanese
             to input: type "C-x 8 RET 201c" or "C-x 8 RET LEFT DOUBLE 
QUOTATION MARK"
          buffer code: #xE2 #x80 #x9C
            file code: #xE2 #x80 #x9C (encoded by coding system nil)
              display: by display table entry [?"] (see below)

The display table entry is displayed by these fonts (glyph codes):
": xft:-MS  -Consolas-normal-normal-normal-*-19-*-*-*-m-0-iso10646-1 (#x251)
 face: ‘homoglyph’

Character code properties: customize what to show
  name: LEFT DOUBLE QUOTATION MARK
  old-name: DOUBLE TURNED COMMA QUOTATION MARK
  general-category: Pi (Punctuation, Initial quote)
  decomposition: (8220) ('“')

There are text properties here:
  face                 gnus-summary-normal-ancient
  gnus-number          14350


In GNU Emacs 26.0.50.1 (x86_64-pc-linux-gnu, X toolkit)
 of 2016-10-21 built on qcore
Repository revision: 0929e061fb544c0f4c10ff0412a41cf7e8148270
Windowing system distributor 'The X.Org Foundation', version 11.0.11804000
System Description:     Ubuntu 16.10

Configured using:
 'configure --without-toolkit-scroll-bars --with-x-toolkit=lucid'

Configured features:
XAW3D XPM JPEG TIFF GIF PNG SOUND GSETTINGS NOTIFY GNUTLS LIBXML2
FREETYPE XFT ZLIB LUCID X11

Important settings:
  value of $LANG: C
  locale-coding-system: nil