QFontDatabase: Use more explicit function name for clearing families

Avoids overloading on ::free() from stdlib.h

Change-Id: I71d7fa4012f189cf5640968ed43d530eff79989f
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>

src/gui/text/qfontdatabase.cpp

@@ -298,12 +298,22 @@ void QtFontFamily::ensurePopulated()
     Q_ASSERT_X(populated, Q_FUNC_INFO, qPrintable(name));
 }
 
+void QFontDatabasePrivate::clearFamilies()
+{
+    while (count--)
+        delete families[count];
+    ::free(families);
+    families = nullptr;
+    count = 0;
+    // don't clear the memory fonts!
+}
+
 void QFontDatabasePrivate::invalidate()
 {
     QFontCache::instance()->clear();
 
     fallbacksCache.clear();
-    free();
+    clearFamilies();
     QGuiApplicationPrivate::platformIntegration()->fontDatabase()->invalidate();
     emit static_cast<QGuiApplication *>(QCoreApplication::instance())->fontDatabaseChanged();
 }
@@ -530,7 +540,7 @@ void qt_cleanupFontDatabase()
 {
     auto *db = QFontDatabasePrivate::instance();
     db->fallbacksCache.clear();
-    db->free();
+    db->clearFamilies();
 }
 
 // used in qfont.cpp

src/gui/text/qfontdatabase_p.h

@@ -221,9 +221,11 @@ public:
     { }
 
     ~QFontDatabasePrivate() {
-        free();
+        clearFamilies();
     }
 
+    void clearFamilies();
+
     enum FamilyRequestFlags {
         RequestFamily = 0,
         EnsureCreated,
@@ -231,14 +233,6 @@ public:
     };
 
     QtFontFamily *family(const QString &f, FamilyRequestFlags flags = EnsurePopulated);
-    void free() {
-        while (count--)
-            delete families[count];
-        ::free(families);
-        families = nullptr;
-        count = 0;
-        // don't clear the memory fonts!
-    }
 
     int count;
     QtFontFamily **families;