Backport additional fixes for emoji support

Resolves: RHEL-4218

qt6-qtbase.spec

@@ -47,7 +47,7 @@ BuildRequires: pkgconfig(libsystemd)
 Name:    qt6-qtbase
 Summary: Qt6 - QtBase components
 Version: 6.8.1
-Release: 5%{?dist}
+Release: 6%{?dist}
 
 License: LGPL-3.0-only OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 Url:     http://qt-project.org/
@@ -100,6 +100,9 @@ Patch58: qtbase-libglvnd.patch
 Patch150: qtbase-extract-emoji-data-from-unicode-files.patch
 Patch151: qtbase-introduce-emoji-segmenter-to-3rdparty-code.patch
 Patch152: qtbase-use-emoji-segmenter-to-apply-emoji-fonts-automatically.patch
+Patch153: qtbase-dont-support-subpixel-positioning-for-color-fonts.patch
+Patch154: qtbase-fix-regression-when-looking-up-fallback-fonts.patch
+Patch155: qtbase-skip-ad-hoc-handling-of-variation-selector-in-font-merging.patch
 
 ## RHEL specific patches
 # Patch300: qtbase-fix-tests.patch
@@ -912,6 +915,10 @@ make check -k ||:
 %endif
 
 %changelog
+* Mon Dec 16 2024 Jan Grulich <jgrulich@redhat.com> - 6.8.1-6
+- Backport additional fixes for emoji support
+  Resolves: RHEL-4218
+
 * Wed Dec 11 2024 Jan Grulich <jgrulich@redhat.com> - 6.8.1-5
 - Move libcupsprintersupport back to -gui as it depends on gui libs
   Resolves: RHEL-53982

qtbase-dont-support-subpixel-positioning-for-color-fonts.patch

@@ -0,0 +1,55 @@
+From fd9c9788f73cb088229701dd92443aa04005a4a3 Mon Sep 17 00:00:00 2001
+From: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
+Date: Tue, 26 Nov 2024 10:47:30 +0100
+Subject: Don't support subpixel positioning for color fonts
+
+This comes at a price and it does not really make sense for
+emojis.
+
+Pick-to: 6.8
+Change-Id: I57148bff48a48bb81a03203626df25646c9acb6a
+Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
+
+diff --git a/src/gui/text/coretext/qfontengine_coretext_p.h b/src/gui/text/coretext/qfontengine_coretext_p.h
+index 1b8a7e0d2a..726abd61d5 100644
+--- a/src/gui/text/coretext/qfontengine_coretext_p.h
++++ b/src/gui/text/coretext/qfontengine_coretext_p.h
+@@ -54,7 +54,7 @@ public:
+     bool canRender(const QChar *string, int len) const override;
+ 
+     int synthesized() const override { return synthesisFlags; }
+-    bool supportsHorizontalSubPixelPositions() const override { return true; }
++    bool supportsHorizontalSubPixelPositions() const override { return !isColorFont(); }
+     bool supportsVerticalSubPixelPositions() const override { return false; }
+ 
+     QFixed lineThickness() const override;
+diff --git a/src/gui/text/freetype/qfontengine_ft_p.h b/src/gui/text/freetype/qfontengine_ft_p.h
+index d2fa82b81d..924131699a 100644
+--- a/src/gui/text/freetype/qfontengine_ft_p.h
++++ b/src/gui/text/freetype/qfontengine_ft_p.h
+@@ -158,8 +158,9 @@ private:
+     QFixed emSquareSize() const override;
+     bool supportsHorizontalSubPixelPositions() const override
+     {
+-        return default_hint_style == HintLight ||
+-               default_hint_style == HintNone;
++        return !isColorFont()
++                && (default_hint_style == HintLight ||
++                    default_hint_style == HintNone);
+     }
+ 
+     bool supportsVerticalSubPixelPositions() const override
+diff --git a/src/gui/text/windows/qwindowsfontenginedirectwrite.cpp b/src/gui/text/windows/qwindowsfontenginedirectwrite.cpp
+index 3ab6fe723d..049a3e5885 100644
+--- a/src/gui/text/windows/qwindowsfontenginedirectwrite.cpp
++++ b/src/gui/text/windows/qwindowsfontenginedirectwrite.cpp
+@@ -749,7 +749,8 @@ QImage QWindowsFontEngineDirectWrite::alphaMapForGlyph(glyph_t glyph,
+ bool QWindowsFontEngineDirectWrite::supportsHorizontalSubPixelPositions() const
+ {
+     DWRITE_RENDERING_MODE renderMode = hintingPreferenceToRenderingMode(fontDef);
+-    return  (renderMode != DWRITE_RENDERING_MODE_GDI_CLASSIC
++    return  (!isColorFont()
++            && renderMode != DWRITE_RENDERING_MODE_GDI_CLASSIC
+             && renderMode != DWRITE_RENDERING_MODE_GDI_NATURAL
+             && renderMode != DWRITE_RENDERING_MODE_ALIASED);
+ }

qtbase-fix-regression-when-looking-up-fallback-fonts.patch

@@ -0,0 +1,96 @@
+From 486bbc7a5bc4483ecc2a6b8927543725e3d38722 Mon Sep 17 00:00:00 2001
+From: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
+Date: Tue, 26 Nov 2024 14:39:44 +0100
+Subject: Fix regression when looking up fallback fonts
+
+This amends 16850709306589a2433c0038605d365a6b6bedad.
+
+In that change, the final pass for looking up fallback
+fonts was turned into a lambda so that we could run it
+an additional time at the very end. However, when making
+a lambda from the code, some of the logic was accidentally
+changed.
+
+Specifically, for multi engines the original code would pass
+Script_Common instead of the requested script to the match()
+function, but it would still pass the actual script to
+loadEngine() as well as store it in the key. In the changed
+code, Script_Common would be used for all of these when multi
+was true.
+
+This change was not intentional and it caused us to fail to
+load certain fallback fonts, for instance the Bengali font
+on Windows.
+
+Fixes: QTBUG-131632
+Change-Id: Id215ee4dc2851e846be27a3a25a31cad57b8f67d
+Reviewed-by: Lars Knoll <lars@knoll.priv.no>
+
+diff --git a/src/gui/text/qfontdatabase.cpp b/src/gui/text/qfontdatabase.cpp
+index 96c2337e..0c2a4b66 100644
+--- a/src/gui/text/qfontdatabase.cpp
++++ b/src/gui/text/qfontdatabase.cpp
+@@ -2734,17 +2734,23 @@ QFontEngine *QFontDatabasePrivate::findFont(const QFontDef &req,
+             if (script > QChar::Script_Common)
+                 fallbacks += QString(); // Find the first font matching the specified script.
+ 
+-            auto findMatchingFallback = [&](int xscript) {
++            auto findMatchingFallback = [&fallbacks,
++                                         &index,
++                                         &multi,
++                                         &fontCache,
++                                         &blackListed,
++                                         &request](int lookupScript, int cacheScript) {
++                QFontEngine *engine = nullptr;
+                 for (int i = 0; !engine && i < fallbacks.size(); i++) {
+                     QFontDef def = request;
+ 
+                     def.families = QStringList(fallbacks.at(i));
+-                    QFontCache::Key key(def, xscript, multi ? 1 : 0);
++                    QFontCache::Key key(def, cacheScript, multi ? 1 : 0);
+                     engine = fontCache->findEngine(key);
+                     if (!engine) {
+                         QtFontDesc desc;
+                         do {
+-                            index = match(xscript,
++                            index = match(lookupScript,
+                                           def,
+                                           def.families.constFirst(),
+                                           ""_L1,
+@@ -2755,7 +2761,12 @@ QFontEngine *QFontDatabasePrivate::findFont(const QFontDef &req,
+                                 QFontDef loadDef = def;
+                                 if (loadDef.families.isEmpty())
+                                     loadDef.families = QStringList(desc.family->name);
+-                                engine = loadEngine(xscript, loadDef, desc.family, desc.foundry, desc.style, desc.size);
++                                engine = loadEngine(cacheScript,
++                                                    loadDef,
++                                                    desc.family,
++                                                    desc.foundry,
++                                                    desc.style,
++                                                    desc.size);
+                                 if (engine)
+                                     initFontDef(desc, loadDef, &engine->fontDef, multi);
+                                 else
+@@ -2764,15 +2775,20 @@ QFontEngine *QFontDatabasePrivate::findFont(const QFontDef &req,
+                         } while (index >= 0 && !engine);
+                     }
+                 }
++
++                return engine;
+             };
+ 
+-            findMatchingFallback(multi && script != QFontDatabasePrivate::Script_Emoji ? QChar::Script_Common: script);
++            engine = findMatchingFallback(multi && script != QFontDatabasePrivate::Script_Emoji
++                                          ? QChar::Script_Common
++                                          : script,
++                                          script);
+ 
+             // If we are looking for a color font and there are no color fonts on the system,
+             // we will end up here, for one final pass. This is a rare occurrence so we accept
+             // and extra pass on the fallbacks for this.
+             if (!engine && script == QFontDatabasePrivate::Script_Emoji)
+-                findMatchingFallback(QChar::Script_Common);
++                engine = findMatchingFallback(QChar::Script_Common, script);
+         }
+ 
+         if (!engine)

qtbase-introduce-emoji-segmenter-to-3rdparty-code.patch

@@ -1,7 +1,7 @@
 From aa7d479be0df3e118580e87f30e061445dfb37e3 Mon Sep 17 00:00:00 2001
 From: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
-Date: Fri, 02 Feb 2024 15:45:20 +0100
+Date: Fri, 2 Feb 2024 15:45:20 +0100
-Subject: [PATCH] Introduce emoji-segmenter to 3rdparty code
+Subject: Introduce emoji-segmenter to 3rdparty code
 
 This is a parser for emoji sequences developed by Google
 which is used in multiple other projects for parsing
@@ -15,13 +15,12 @@ This can be configured using the -emojisegmenter option.
 Task-number: QTBUG-111801
 Change-Id: I7f87b0751415024d29f074d133850027f0003e29
 Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
----
 
 diff --git a/config_help.txt b/config_help.txt
-index 039582da..417c2067 100644
+index deb38c9c2f..09aebf2e65 100644
 --- a/config_help.txt
 +++ b/config_help.txt
-@@ -295,6 +295,7 @@ Gui, printing, widget options:
+@@ -298,6 +298,7 @@ Gui, printing, widget options:
  
    -cups ................ Enable CUPS support [auto] (Unix only)
  
@@ -31,7 +30,7 @@ index 039582da..417c2067 100644
    -harfbuzz ............ Select used HarfBuzz-NG [system/qt/no]
 diff --git a/src/3rdparty/emoji-segmenter/CONTRIBUTING.md b/src/3rdparty/emoji-segmenter/CONTRIBUTING.md
 new file mode 100644
-index 00000000..db177d4a
+index 0000000000..db177d4ac7
 --- /dev/null
 +++ b/src/3rdparty/emoji-segmenter/CONTRIBUTING.md
 @@ -0,0 +1,28 @@
@@ -65,7 +64,7 @@ index 00000000..db177d4a
 +[Google's Open Source Community Guidelines](https://opensource.google.com/conduct/).
 diff --git a/src/3rdparty/emoji-segmenter/NEWS b/src/3rdparty/emoji-segmenter/NEWS
 new file mode 100644
-index 00000000..3fd07f1c
+index 0000000000..3fd07f1ce2
 --- /dev/null
 +++ b/src/3rdparty/emoji-segmenter/NEWS
 @@ -0,0 +1,28 @@
@@ -99,7 +98,7 @@ index 00000000..3fd07f1c
 +* Initial release
 diff --git a/src/3rdparty/emoji-segmenter/README.md b/src/3rdparty/emoji-segmenter/README.md
 new file mode 100644
-index 00000000..571a1a45
+index 0000000000..571a1a4515
 --- /dev/null
 +++ b/src/3rdparty/emoji-segmenter/README.md
 @@ -0,0 +1,103 @@
@@ -208,7 +207,7 @@ index 00000000..571a1a45
 +See the CONTRIBUTING.md file for how to contribute.
 diff --git a/src/3rdparty/emoji-segmenter/REUSE.toml b/src/3rdparty/emoji-segmenter/REUSE.toml
 new file mode 100644
-index 00000000..53d2dc47
+index 0000000000..53d2dc47c7
 --- /dev/null
 +++ b/src/3rdparty/emoji-segmenter/REUSE.toml
 @@ -0,0 +1,7 @@
@@ -221,7 +220,7 @@ index 00000000..53d2dc47
 +SPDX-License-Identifier = "Apache-2.0"
 diff --git a/src/3rdparty/emoji-segmenter/emoji_presentation_scanner.c b/src/3rdparty/emoji-segmenter/emoji_presentation_scanner.c
 new file mode 100644
-index 00000000..00b7700a
+index 0000000000..00b7700a9a
 --- /dev/null
 +++ b/src/3rdparty/emoji-segmenter/emoji_presentation_scanner.c
 @@ -0,0 +1,251 @@
@@ -478,7 +477,7 @@ index 00000000..00b7700a
 +}
 diff --git a/src/3rdparty/emoji-segmenter/patch/0001-Compile-with-warnings-are-errors.patch b/src/3rdparty/emoji-segmenter/patch/0001-Compile-with-warnings-are-errors.patch
 new file mode 100644
-index 00000000..0cc1868c
+index 0000000000..0cc1868ca7
 --- /dev/null
 +++ b/src/3rdparty/emoji-segmenter/patch/0001-Compile-with-warnings-are-errors.patch
 @@ -0,0 +1,26 @@
@@ -510,7 +509,7 @@ index 00000000..0cc1868c
 +
 diff --git a/src/3rdparty/emoji-segmenter/qt_attribution.json b/src/3rdparty/emoji-segmenter/qt_attribution.json
 new file mode 100644
-index 00000000..64083381
+index 0000000000..64083381d4
 --- /dev/null
 +++ b/src/3rdparty/emoji-segmenter/qt_attribution.json
 @@ -0,0 +1,16 @@
@@ -531,10 +530,10 @@ index 00000000..64083381
 +    "Copyright": "Copyright 2019 Google LLC"
 +}
 diff --git a/src/gui/configure.cmake b/src/gui/configure.cmake
-index 0e53f512..44bef7d3 100644
+index b7c1e8e00c..7889445976 100644
 --- a/src/gui/configure.cmake
 +++ b/src/gui/configure.cmake
-@@ -689,6 +689,12 @@ qt_feature("direct2d1_1" PRIVATE
+@@ -699,6 +699,12 @@ qt_feature("direct2d1_1" PRIVATE
      LABEL "Direct 2D 1.1"
      CONDITION QT_FEATURE_direct2d AND TEST_d2d1_1
  )
@@ -547,7 +546,7 @@ index 0e53f512..44bef7d3 100644
  qt_feature("evdev" PRIVATE
      LABEL "evdev"
      CONDITION QT_FEATURE_thread AND TEST_evdev
-@@ -1285,6 +1291,7 @@ qt_feature("wayland" PUBLIC
+@@ -1299,6 +1305,7 @@ qt_feature("wayland" PUBLIC
  
  qt_configure_add_summary_section(NAME "Qt Gui")
  qt_configure_add_summary_entry(ARGS "accessibility")
@@ -556,7 +555,7 @@ index 0e53f512..44bef7d3 100644
  qt_configure_add_summary_entry(ARGS "system-freetype")
  qt_configure_add_summary_entry(ARGS "harfbuzz")
 diff --git a/src/gui/qt_cmdline.cmake b/src/gui/qt_cmdline.cmake
-index 446618eb..5465b2c6 100644
+index 446618ebc4..5465b2c63e 100644
 --- a/src/gui/qt_cmdline.cmake
 +++ b/src/gui/qt_cmdline.cmake
 @@ -10,6 +10,7 @@ qt_commandline_option(eglfs TYPE boolean)

qtbase-skip-ad-hoc-handling-of-variation-selector-in-font-merging.patch

@@ -0,0 +1,55 @@
+From cb2633468413d8c2a9e28d4c4a10b25e90dd3116 Mon Sep 17 00:00:00 2001
+From: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
+Date: Mon, 25 Nov 2024 16:05:09 +0100
+Subject: Skip ad hoc handling of variation selector in font merging
+
+Since we now support emoji parsing, there is no longer any need
+for this ad hoc processing of VS-16. The exception is if Qt is
+built without the emoji segmenter, in which case we should keep
+it for consistency with previous versions.
+
+Task-number: QTBUG-111801
+Change-Id: I3e243b9610fe55dda26eba63ac849e6afa22a185
+Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
+
+diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp
+index 02595b40c5..6be6a5aca2 100644
+--- a/src/gui/text/qfontengine.cpp
++++ b/src/gui/text/qfontengine.cpp
+@@ -1997,8 +1997,11 @@ int QFontEngineMulti::stringToCMap(const QChar *str, int len,
+     int glyph_pos = 0;
+     QStringIterator it(str, str + len);
+ 
+-    int lastFallback = -1;
++#if defined(QT_NO_EMOJISEGMENTER)
+     char32_t previousUcs4 = 0;
++#endif
++
++    int lastFallback = -1;
+     while (it.hasNext()) {
+         const char32_t ucs4 = it.peekNext();
+ 
+@@ -2057,6 +2060,7 @@ int QFontEngineMulti::stringToCMap(const QChar *str, int len,
+                 }
+             }
+ 
++#if defined(QT_NO_EMOJISEGMENTER)
+             // For variant-selectors, they are modifiers to the previous character. If we
+             // end up with different font selections for the selector and the character it
+             // modifies, we try applying the selector font to the preceding character as well
+@@ -2095,11 +2099,15 @@ int QFontEngineMulti::stringToCMap(const QChar *str, int len,
+                     }
+                 }
+             }
++#endif
+         }
+ 
+         it.advance();
+         ++glyph_pos;
++
++#if defined(QT_NO_EMOJISEGMENTER)
+         previousUcs4 = ucs4;
++#endif
+     }
+ 
+     *nglyphs = glyph_pos;

qtbase-use-emoji-segmenter-to-apply-emoji-fonts-automatically.patch

@@ -1,7 +1,7 @@
 From 16850709306589a2433c0038605d365a6b6bedad Mon Sep 17 00:00:00 2001
 From: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
-Date: Tue, 02 Apr 2024 13:20:34 +0200
+Date: Tue, 2 Apr 2024 13:20:34 +0200
-Subject: [PATCH] Use emoji segmenter to apply emoji fonts automatically
+Subject: Use emoji segmenter to apply emoji fonts automatically
 
 Colorful emojis in Unicode are not isolated to specific ranges
 of code points like other writing systems. Instead, there are