[issue39600] idle_test: test_fontlist_key() fails if two font families have the same name

[STINNER Victor]

STINNER Victor <vstinner at python.org> added the comment:

In LibreOffice, I see 4 flavors of "Cantarell" with different *weight* :

Cantarell
Cantarell Extra Bold
Cantarell Light
Cantarell Thin

whereas tkinter.font.families(frame) returns 4 times the same string: "Cantarell". The C function of Tk is TkpGetFontFamilies().

The X11 implementation uses XListFonts() which returns a string like "-foundry-family-weight-slant-(...)" but the function only returns the "family" substring: it ignores the foundy and the weight for example. So it's not surprising to get duplicates. Example: "-adobe-helvetica-bold-o-normal--11-80-100-100-p-60-iso8859-1" becomes "helvetica".

There is also a Xft implementation which uses XftListFonts(). Then it uses XftPatternGetString() to get a font family.

I see no logic in Tcl to exclude duplicated family names of different weights.

--

>>> tkinter.font.names(frame)
('TkCaptionFont', 'TkSmallCaptionFont', 'TkTooltipFont', 'TkFixedFont', 'TkHeadingFont', 'TkMenuFont', 'TkIconFont', 'TkTextFont', 'TkDefaultFont')

That's something different that I would call unrelated ;-)

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<https://bugs.python.org/issue39600>
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