Windows QPA: Fix the signature of the font enumeration callbacks.

Instead of casting the function in the calls to EnumFontFamiliesEx(),
use the correct signature and cast inside the callbacks. Also
avoid unconditionally casting the TEXTMETRIC parameter to
NEWTEXTMETRICEX since according to documentation
NEWTEXTMETRICEX is passed for TrueType fonts only.

Task-number: QTBUG-50804
Change-Id: I0393474ac06000fc3f12d2dbc2a5aa37a6b44849
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>

2 files changed, 46 insertions, 39 deletions

diff --git a/src/plugins/platforms/windows/qwindowsfontdatabase.cpp b/src/plugins/platforms/windows/qwindowsfontdatabase.cpp
index bf42ca190b..1adf4115c9 100644
--- a/src/plugins/platforms/windows/qwindowsfontdatabase.cpp
+++ b/src/plugins/platforms/windows/qwindowsfontdatabase.cpp
@@ -870,14 +870,13 @@ static bool addFontToDatabase(const QString &familyName, uchar charSet,
 
     static const int SMOOTH_SCALABLE = 0xffff;
     const QString foundryName; // No such concept.
-    const NEWTEXTMETRIC *tm = (NEWTEXTMETRIC *)textmetric;
-    const bool fixed = !(tm->tmPitchAndFamily & TMPF_FIXED_PITCH);
-    const bool ttf = (tm->tmPitchAndFamily & TMPF_TRUETYPE);
-    const bool scalable = tm->tmPitchAndFamily & (TMPF_VECTOR|TMPF_TRUETYPE);
-    const int size = scalable ? SMOOTH_SCALABLE : tm->tmHeight;
-    const QFont::Style style = tm->tmItalic ? QFont::StyleItalic : QFont::StyleNormal;
+    const bool fixed = !(textmetric->tmPitchAndFamily & TMPF_FIXED_PITCH);
+    const bool ttf = (textmetric->tmPitchAndFamily & TMPF_TRUETYPE);
+    const bool scalable = textmetric->tmPitchAndFamily & (TMPF_VECTOR|TMPF_TRUETYPE);
+    const int size = scalable ? SMOOTH_SCALABLE : textmetric->tmHeight;
+    const QFont::Style style = textmetric->tmItalic ? QFont::StyleItalic : QFont::StyleNormal;
     const bool antialias = false;
-    const QFont::Weight weight = QPlatformFontDatabase::weightFromInteger(tm->tmWeight);
+    const QFont::Weight weight = QPlatformFontDatabase::weightFromInteger(textmetric->tmWeight);
     const QFont::Stretch stretch = QFont::Unstretched;
 
 #ifndef QT_NO_DEBUG_OUTPUT
@@ -957,18 +956,21 @@ static bool addFontToDatabase(const QString &familyName, uchar charSet,
     return true;
 }
 
-static int QT_WIN_CALLBACK storeFont(ENUMLOGFONTEX* f, NEWTEXTMETRICEX *textmetric,
-                                     int type, LPARAM registerAlias)
+static int QT_WIN_CALLBACK storeFont(const LOGFONT *logFont, const TEXTMETRIC *textmetric,
+                                     DWORD type, LPARAM lParam)
 {
+    const ENUMLOGFONTEX *f = reinterpret_cast<const ENUMLOGFONTEX *>(logFont);
     const QString familyName = QString::fromWCharArray(f->elfLogFont.lfFaceName);
     const uchar charSet = f->elfLogFont.lfCharSet;
+    const bool registerAlias = bool(lParam);
 
-    const FONTSIGNATURE signature = textmetric->ntmFontSig;
-
-    // NEWTEXTMETRICEX is a NEWTEXTMETRIC, which according to the documentation is
-    // identical to a TEXTMETRIC except for the last four members, which we don't use
-    // anyway
-    addFontToDatabase(familyName, charSet, (TEXTMETRIC *)textmetric, &signature, type, registerAlias);
+    // NEWTEXTMETRICEX (passed for TT fonts) is a NEWTEXTMETRIC, which according
+    // to the documentation is identical to a TEXTMETRIC except for the last four
+    // members, which we don't use anyway
+    const FONTSIGNATURE *signature = Q_NULLPTR;
+    if (type & TRUETYPE_FONTTYPE)
+        signature = &reinterpret_cast<const NEWTEXTMETRICEX *>(textmetric)->ntmFontSig;
+    addFontToDatabase(familyName, charSet, textmetric, signature, type, registerAlias);
 
     // keep on enumerating
     return 1;
@@ -987,7 +989,7 @@ void QWindowsFontDatabase::populateFamily(const QString &familyName, bool regist
     familyName.toWCharArray(lf.lfFaceName);
     lf.lfFaceName[familyName.size()] = 0;
     lf.lfPitchAndFamily = 0;
-    EnumFontFamiliesEx(dummy, &lf, (FONTENUMPROC)storeFont, (LPARAM)registerAlias, 0);
+    EnumFontFamiliesEx(dummy, &lf, storeFont, LPARAM(registerAlias), 0);
     ReleaseDC(0, dummy);
 }
 
@@ -1008,9 +1010,11 @@ struct PopulateFamiliesContext
 };
 } // namespace
 
-static int QT_WIN_CALLBACK populateFontFamilies(ENUMLOGFONTEX* f, NEWTEXTMETRICEX *tm, int, LPARAM lparam)
+static int QT_WIN_CALLBACK populateFontFamilies(const LOGFONT *logFont, const TEXTMETRIC *textmetric,
+                                                DWORD, LPARAM lparam)
 {
     // the "@family" fonts are just the same as "family". Ignore them.
+    const ENUMLOGFONTEX *f = reinterpret_cast<const ENUMLOGFONTEX *>(logFont);
     const wchar_t *faceNameW = f->elfLogFont.lfFaceName;
     if (faceNameW[0] && faceNameW[0] != L'@' && wcsncmp(faceNameW, L"WST_", 4)) {
         const QString faceName = QString::fromWCharArray(faceNameW);
@@ -1020,7 +1024,7 @@ static int QT_WIN_CALLBACK populateFontFamilies(ENUMLOGFONTEX* f, NEWTEXTMETRICE
             context->seenSystemDefaultFont = true;
 
         // Register current font's english name as alias
-        const bool ttf = (tm->ntmTm.tmPitchAndFamily & TMPF_TRUETYPE);
+        const bool ttf = textmetric->tmPitchAndFamily & TMPF_TRUETYPE;
         if (ttf && localizedName(faceName)) {
             const QString englishName = getEnglishName(faceName);
             if (!englishName.isEmpty()) {
@@ -1044,7 +1048,7 @@ void QWindowsFontDatabase::populateFontDatabase()
     lf.lfFaceName[0] = 0;
     lf.lfPitchAndFamily = 0;
     PopulateFamiliesContext context(QWindowsFontDatabase::systemDefaultFont().family());
-    EnumFontFamiliesEx(dummy, &lf, (FONTENUMPROC)populateFontFamilies, reinterpret_cast<LPARAM>(&context), 0);
+    EnumFontFamiliesEx(dummy, &lf, populateFontFamilies, reinterpret_cast<LPARAM>(&context), 0);
     ReleaseDC(0, dummy);
     // Work around EnumFontFamiliesEx() not listing the system font.
     if (!context.seenSystemDefaultFont)
diff --git a/src/plugins/platforms/windows/qwindowsfontdatabase_ft.cpp b/src/plugins/platforms/windows/qwindowsfontdatabase_ft.cpp
index 88ceb37693..823c3e7c7b 100644
--- a/src/plugins/platforms/windows/qwindowsfontdatabase_ft.cpp
+++ b/src/plugins/platforms/windows/qwindowsfontdatabase_ft.cpp
@@ -392,14 +392,13 @@ static bool addFontToDatabase(const QString &faceName,
 
     static const int SMOOTH_SCALABLE = 0xffff;
     const QString foundryName; // No such concept.
-    const NEWTEXTMETRIC *tm = (NEWTEXTMETRIC *)textmetric;
-    const bool fixed = !(tm->tmPitchAndFamily & TMPF_FIXED_PITCH);
-    const bool ttf = (tm->tmPitchAndFamily & TMPF_TRUETYPE);
-    const bool scalable = tm->tmPitchAndFamily & (TMPF_VECTOR|TMPF_TRUETYPE);
-    const int size = scalable ? SMOOTH_SCALABLE : tm->tmHeight;
-    const QFont::Style style = tm->tmItalic ? QFont::StyleItalic : QFont::StyleNormal;
+    const bool fixed = !(textmetric->tmPitchAndFamily & TMPF_FIXED_PITCH);
+    const bool ttf = (textmetric->tmPitchAndFamily & TMPF_TRUETYPE);
+    const bool scalable = textmetric->tmPitchAndFamily & (TMPF_VECTOR|TMPF_TRUETYPE);
+    const int size = scalable ? SMOOTH_SCALABLE : textmetric->tmHeight;
+    const QFont::Style style = textmetric->tmItalic ? QFont::StyleItalic : QFont::StyleNormal;
     const bool antialias = false;
-    const QFont::Weight weight = QPlatformFontDatabase::weightFromInteger(tm->tmWeight);
+    const QFont::Weight weight = QPlatformFontDatabase::weightFromInteger(textmetric->tmWeight);
     const QFont::Stretch stretch = QFont::Unstretched;
 
 #ifndef QT_NO_DEBUG_STREAM
@@ -516,19 +515,21 @@ static QByteArray getFntTable(HFONT hfont, uint tag)
 }
 #endif
 
-static int QT_WIN_CALLBACK storeFont(ENUMLOGFONTEX* f, NEWTEXTMETRICEX *textmetric,
-                                     int type, LPARAM)
+static int QT_WIN_CALLBACK storeFont(const LOGFONT *logFont, const TEXTMETRIC *textmetric,
+                                     DWORD type, LPARAM)
 {
-
+    const ENUMLOGFONTEX *f = reinterpret_cast<const ENUMLOGFONTEX *>(logFont);
     const QString faceName = QString::fromWCharArray(f->elfLogFont.lfFaceName);
     const QString fullName = QString::fromWCharArray(f->elfFullName);
     const uchar charSet = f->elfLogFont.lfCharSet;
 
-    const FONTSIGNATURE signature = textmetric->ntmFontSig;
-    // NEWTEXTMETRICEX is a NEWTEXTMETRIC, which according to the documentation is
-    // identical to a TEXTMETRIC except for the last four members, which we don't use
-    // anyway
-    addFontToDatabase(faceName, fullName, charSet, (TEXTMETRIC *)textmetric, &signature, type, false);
+    // NEWTEXTMETRICEX (passed for TT fonts) is a NEWTEXTMETRIC, which according
+    // to the documentation is identical to a TEXTMETRIC except for the last four
+    // members, which we don't use anyway
+    const FONTSIGNATURE *signature = Q_NULLPTR;
+    if (type & TRUETYPE_FONTTYPE)
+        signature = &reinterpret_cast<const NEWTEXTMETRICEX *>(textmetric)->ntmFontSig;
+    addFontToDatabase(faceName, fullName, charSet, textmetric, signature, type, false);
 
     // keep on enumerating
     return 1;
@@ -555,7 +556,7 @@ void QWindowsFontDatabaseFT::populateFamily(const QString &familyName)
     familyName.toWCharArray(lf.lfFaceName);
     lf.lfFaceName[familyName.size()] = 0;
     lf.lfPitchAndFamily = 0;
-    EnumFontFamiliesEx(dummy, &lf, (FONTENUMPROC)storeFont, 0, 0);
+    EnumFontFamiliesEx(dummy, &lf, storeFont, 0, 0);
     ReleaseDC(0, dummy);
 }
 
@@ -575,17 +576,20 @@ struct PopulateFamiliesContext
 
 // Delayed population of font families
 
-static int QT_WIN_CALLBACK populateFontFamilies(ENUMLOGFONTEX* f, NEWTEXTMETRICEX *tm, int, LPARAM lparam)
+static int QT_WIN_CALLBACK populateFontFamilies(const LOGFONT *logFont, const TEXTMETRIC *textmetric,
+                                                DWORD, LPARAM lparam)
 {
+    const ENUMLOGFONTEX *f = reinterpret_cast<const ENUMLOGFONTEX *>(logFont);
     // the "@family" fonts are just the same as "family". Ignore them.
     const wchar_t *faceNameW = f->elfLogFont.lfFaceName;
     if (faceNameW[0] && faceNameW[0] != L'@' && wcsncmp(faceNameW, L"WST_", 4)) {
         // Register only font families for which a font file exists for delayed population
+        const bool ttf = textmetric->tmPitchAndFamily & TMPF_TRUETYPE;
         const QString faceName = QString::fromWCharArray(faceNameW);
         const FontKey *key = findFontKey(faceName);
         if (!key) {
             key = findFontKey(QString::fromWCharArray(f->elfFullName));
-            if (!key && (tm->ntmTm.tmPitchAndFamily & TMPF_TRUETYPE) && localizedName(faceName))
+            if (!key && ttf && localizedName(faceName))
                 key = findFontKey(getEnglishName(faceName));
         }
         if (key) {
@@ -595,7 +599,6 @@ static int QT_WIN_CALLBACK populateFontFamilies(ENUMLOGFONTEX* f, NEWTEXTMETRICE
                 context->seenSystemDefaultFont = true;
 
             // Register current font's english name as alias
-            const bool ttf = (tm->ntmTm.tmPitchAndFamily & TMPF_TRUETYPE);
             if (ttf && localizedName(faceName)) {
                 const QString englishName = getEnglishName(faceName);
                 if (!englishName.isEmpty()) {
@@ -619,7 +622,7 @@ void QWindowsFontDatabaseFT::populateFontDatabase()
     lf.lfFaceName[0] = 0;
     lf.lfPitchAndFamily = 0;
     PopulateFamiliesContext context(QWindowsFontDatabase::systemDefaultFont().family());
-    EnumFontFamiliesEx(dummy, &lf, (FONTENUMPROC)populateFontFamilies, reinterpret_cast<LPARAM>(&context), 0);
+    EnumFontFamiliesEx(dummy, &lf, populateFontFamilies, reinterpret_cast<LPARAM>(&context), 0);
     ReleaseDC(0, dummy);
     // Work around EnumFontFamiliesEx() not listing the system font
     if (!context.seenSystemDefaultFont)