1 files changed, 4 insertions, 0 deletions
diff --git a/src/gui/text/qfontdatabase_p.h b/src/gui/text/qfontdatabase_p.h
index b40a651bbb3..5428e18071f 100644
--- a/src/gui/text/qfontdatabase_p.h
+++ b/src/gui/text/qfontdatabase_p.h
@@ -207,6 +207,10 @@ public:
     QCache<QtFontFallbacksCacheKey, QStringList> fallbacksCache;
     struct ApplicationFont {
         QString fileName;
+
+        // Note: The data may be implicitly shared throughout the
+        // font database and platform font database, so be careful
+        // to never detach when accessing this member!
         QByteArray data;
 
         bool isNull() const { return fileName.isEmpty(); }