tree 1d517178cf7922723de5ea9470ad1b3eee8c8cbb
parent 27d72e2271cd8bfa734e027565776d790284adc9
author carlosgc@webkit.org <carlosgc@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557999076 +0000
committer carlosgc@webkit.org <carlosgc@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557999076 +0000

[FreeType] Some character sequences with a variation selector are not rendered
https://bugs.webkit.org/show_bug.cgi?id=197838

Reviewed by Michael Catanzaro.

We get the invalid glyph instead. See http://mts.io/2015/04/21/unicode-symbol-render-text-emoji/. In the table at
the end the Emoji and Text columns are not correctly rendered. It happens also when copying an emoji from
GtkEmojiChooser and pasting in WebKit text field, because GTK appends U+FE0F to all emojis to force the emoji
style. We need to take into account the variation selector when checking if a font can render a combining
sequence, using FT_Face_GetCharVariantIndex to get the right glyph in case of variation character present.

* platform/graphics/Font.cpp:
(WebCore::Font::platformSupportsCodePoint const): Add optional variation parameter.
(WebCore::Font::canRenderCombiningCharacterSequence const): Take into account variation selector characters
* platform/graphics/Font.h:
* platform/graphics/cairo/FontCairoHarfbuzzNG.cpp:
(WebCore::FontCascade::fontForCombiningCharacterSequence const): Check variation selectors 0xFE0E and 0xFE0F to
decide whether to use the emoji or text style.
* platform/graphics/cocoa/FontCocoa.mm:
(WebCore::Font::platformSupportsCodePoint const): Return false when a variation character is passed so that
characters are checked individually.
* platform/graphics/freetype/SimpleFontDataFreeType.cpp:
(WebCore::Font::platformSupportsCodePoint const): Use FT_Face_GetCharVariantIndex when a variation character is
passed.
* platform/graphics/harfbuzz/ComplexTextControllerHarfBuzz.cpp:
(WebCore::harfBuzzFontFunctions): Do not return true when FT_Face_GetCharVariantIndex returns 0.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@245393 268f45cc-cd09-0410-ab3c-d52691b4dbfc