3 files changed, 83 insertions, 22 deletions
diff --git a/src/gui/text/freetype/qfontengine_ft.cpp b/src/gui/text/freetype/qfontengine_ft.cpp
index 66a46d18cd9..3d41cfda0aa 100644
--- a/src/gui/text/freetype/qfontengine_ft.cpp
+++ b/src/gui/text/freetype/qfontengine_ft.cpp
@@ -278,6 +278,13 @@ QFreetypeFace *QFreetypeFace::getFace(const QFontEngine::FaceId &face_id,
         }
 #endif
         newFreetype->face = face;
+        newFreetype->mm_var = nullptr;
+        if (FT_IS_NAMED_INSTANCE(newFreetype->face)) {
+            FT_Error ftresult;
+            ftresult = FT_Get_MM_Var(face, &newFreetype->mm_var);
+            if (ftresult != FT_Err_Ok)
+                newFreetype->mm_var = nullptr;
+        }
 
         newFreetype->ref.storeRelaxed(1);
         newFreetype->xsize = 0;
@@ -351,6 +358,9 @@ QFreetypeFace *QFreetypeFace::getFace(const QFontEngine::FaceId &face_id,
 void QFreetypeFace::cleanup()
 {
     hbFace.reset();
+    if (mm_var && face && face->glyph)
+        FT_Done_MM_Var(face->glyph->library, mm_var);
+    mm_var = nullptr;
     FT_Done_Face(face);
     face = nullptr;
 }
@@ -818,16 +828,13 @@ bool QFontEngineFT::init(FaceId faceId, bool antialias, GlyphFormat format,
 
 static void dont_delete(void*) {}
 
-static FT_UShort calculateActualWeight(FT_Face face, QFontEngine::FaceId faceId)
+static FT_UShort calculateActualWeight(QFreetypeFace *freetypeFace, FT_Face face, QFontEngine::FaceId faceId)
 {
-    if (faceId.instanceIndex >= 0) {
-        FT_MM_Var *var = nullptr;
-        FT_Get_MM_Var(face, &var);
-        if (var != nullptr && FT_UInt(faceId.instanceIndex) < var->num_namedstyles) {
-            for (FT_UInt axis = 0; axis < var->num_axis; ++axis) {
-                if (var->axis[axis].tag == QFont::Tag("wght").value()) {
-                    return var->namedstyle[faceId.instanceIndex].coords[axis] >> 16;
-                }
+    FT_MM_Var *var = freetypeFace->mm_var;
+    if (var != nullptr && faceId.instanceIndex >= 0 && FT_UInt(faceId.instanceIndex) < var->num_namedstyles) {
+        for (FT_UInt axis = 0; axis < var->num_axis; ++axis) {
+            if (var->axis[axis].tag == QFont::Tag("wght").value()) {
+                return var->namedstyle[faceId.instanceIndex].coords[axis] >> 16;
             }
         }
     }
@@ -838,16 +845,13 @@ static FT_UShort calculateActualWeight(FT_Face face, QFontEngine::FaceId faceId)
     return 700;
 }
 
-static bool calculateActualItalic(FT_Face face, QFontEngine::FaceId faceId)
+static bool calculateActualItalic(QFreetypeFace *freetypeFace, FT_Face face, QFontEngine::FaceId faceId)
 {
-    if (faceId.instanceIndex >= 0) {
-        FT_MM_Var *var = nullptr;
-        FT_Get_MM_Var(face, &var);
-        if (var != nullptr && FT_UInt(faceId.instanceIndex) < var->num_namedstyles) {
-            for (FT_UInt axis = 0; axis < var->num_axis; ++axis) {
-                if (var->axis[axis].tag == QFont::Tag("ital").value()) {
-                    return (var->namedstyle[faceId.instanceIndex].coords[axis] >> 16) == 1;
-                }
+    FT_MM_Var *var = freetypeFace->mm_var;
+    if (var != nullptr && faceId.instanceIndex >= 0 && FT_UInt(faceId.instanceIndex) < var->num_namedstyles) {
+        for (FT_UInt axis = 0; axis < var->num_axis; ++axis) {
+            if (var->axis[axis].tag == QFont::Tag("ital").value()) {
+                return (var->namedstyle[faceId.instanceIndex].coords[axis] >> 16) == 1;
             }
         }
     }
@@ -886,7 +890,7 @@ bool QFontEngineFT::init(FaceId faceId, bool antialias, GlyphFormat format,
     FT_Face face = lockFace();
 
     if (FT_IS_SCALABLE(face)) {
-        bool isItalic = calculateActualItalic(face, faceId);
+        bool isItalic = calculateActualItalic(freetype, face, faceId);
         bool fake_oblique = (fontDef.style != QFont::StyleNormal) && !isItalic && !qEnvironmentVariableIsSet("QT_NO_SYNTHESIZED_ITALIC");
         if (fake_oblique)
             obliquen = true;
@@ -894,7 +898,7 @@ bool QFontEngineFT::init(FaceId faceId, bool antialias, GlyphFormat format,
         freetype->matrix = matrix;
         // fake bold
         if ((fontDef.weight >= QFont::Bold) && !(face->style_flags & FT_STYLE_FLAG_BOLD) && !FT_IS_FIXED_WIDTH(face)  && !qEnvironmentVariableIsSet("QT_NO_SYNTHESIZED_BOLD")) {
-            FT_UShort actualWeight = calculateActualWeight(face, faceId);
+            FT_UShort actualWeight = calculateActualWeight(freetype, face, faceId);
             if (actualWeight < 700 &&
                 (fontDef.pixelSize < 64 || qEnvironmentVariableIsSet("QT_NO_SYNTHESIZED_BOLD_LIMIT"))) {
                 embolden = true;
diff --git a/src/gui/text/freetype/qfontengine_ft_p.h b/src/gui/text/freetype/qfontengine_ft_p.h
index b6315a37d3e..9245a271adc 100644
--- a/src/gui/text/freetype/qfontengine_ft_p.h
+++ b/src/gui/text/freetype/qfontengine_ft_p.h
@@ -19,6 +19,7 @@
 
 #include <ft2build.h>
 #include FT_FREETYPE_H
+#include FT_MULTIPLE_MASTERS_H
 
 
 #ifndef Q_OS_WIN
@@ -62,6 +63,7 @@ public:
     }
 
     FT_Face face;
+    FT_MM_Var *mm_var;
     int xsize; // 26.6
     int ysize; // 26.6
     FT_Matrix matrix;
diff --git a/src/gui/text/unix/qfontconfigdatabase.cpp b/src/gui/text/unix/qfontconfigdatabase.cpp
index a0b1abd14a9..46e8f5724aa 100644
--- a/src/gui/text/unix/qfontconfigdatabase.cpp
+++ b/src/gui/text/unix/qfontconfigdatabase.cpp
@@ -575,6 +575,12 @@ void QFontconfigDatabase::populateFontDatabase()
             FcObjectSetAdd(os, *p);
             ++p;
         }
+
+#ifdef FC_VARIABLE
+        /* Support the named instance of Variable Fonts. */
+        FcPatternAddBool(pattern, FC_VARIABLE, FcFalse);
+#endif
+
         fonts = FcFontList(nullptr, pattern, os);
         FcObjectSetDestroy(os);
         FcPatternDestroy(pattern);
@@ -974,6 +980,7 @@ void QFontconfigDatabase::setupFontEngine(QFontEngineFT *engine, const QFontDef
     QFontEngine::GlyphFormat format;
     // try and get the pattern
     FcPattern *pattern = FcPatternCreate();
+    FcPattern *match = nullptr;
 
     FcValue value;
     value.type = FcTypeString;
@@ -992,7 +999,7 @@ void QFontconfigDatabase::setupFontEngine(QFontEngineFT *engine, const QFontDef
         FcPatternAdd(pattern,FC_INDEX,value,true);
     }
 
-    if (fontDef.pixelSize > 0.1)
+    if (!qFuzzyIsNull(fontDef.pixelSize))
         FcPatternAddDouble(pattern, FC_PIXEL_SIZE, fontDef.pixelSize);
 
     FcResult result;
@@ -1000,7 +1007,55 @@ void QFontconfigDatabase::setupFontEngine(QFontEngineFT *engine, const QFontDef
     FcConfigSubstitute(nullptr, pattern, FcMatchPattern);
     FcDefaultSubstitute(pattern);
 
-    FcPattern *match = FcFontMatch(nullptr, pattern, &result);
+#ifdef FC_VARIABLE
+    if (!fid.filename.isEmpty()) {
+        // FC_INDEX is ignored during processing in FcFontMatch.
+        // So iterate FcPatterns directly and find it out.
+        FcFontSet *fcsets[2], *fcfs;
+
+        fcsets[0] = FcConfigGetFonts(nullptr, FcSetSystem);
+        fcsets[1] = FcConfigGetFonts(nullptr, FcSetApplication);
+        for (int nset = 0; nset < 2; nset++) {
+            fcfs = fcsets[nset];
+            if (fcfs == nullptr)
+                continue;
+            for (int fnum = 0; fnum < fcfs->nfont; fnum++) {
+                FcPattern *fcpat = fcfs->fonts[fnum];
+                FcChar8 *fcfile;
+                FcBool variable;
+                double fcpixelsize;
+                int fcindex;
+
+                // Skip the variable font itself, only to use the named instances and normal fonts here
+                if (FcPatternGetBool(fcpat, FC_VARIABLE, 0, &variable) == FcResultMatch &&
+                    variable == FcTrue)
+                    continue;
+
+                if (!qFuzzyIsNull(fontDef.pixelSize)) {
+                    if (FcPatternGetDouble(fcpat, FC_PIXEL_SIZE, 0, &fcpixelsize) == FcResultMatch &&
+                        fontDef.pixelSize != fcpixelsize)
+                    continue;
+                }
+
+                if (FcPatternGetString(fcpat, FC_FILE, 0, &fcfile) == FcResultMatch &&
+                    FcPatternGetInteger(fcpat, FC_INDEX, 0, &fcindex) == FcResultMatch) {
+                    QByteArray f = QByteArray::fromRawData((const char *)fcfile,
+                                                           qstrlen((const char *)fcfile));
+                    if (f == fid.filename && fcindex == fid.index) {
+                        // We found it.
+                        match = FcFontRenderPrepare(nullptr, pattern, fcpat);
+                        goto bail;
+                    }
+                }
+            }
+        }
+    }
+bail:
+#endif
+
+    if (!match)
+        match = FcFontMatch(nullptr, pattern, &result);
+
     if (match) {
         engine->setDefaultHintStyle(defaultHintStyleFromMatch((QFont::HintingPreference)fontDef.hintingPreference, match, useXftConf));