3 files changed, 13 insertions, 1 deletions
diff --git a/src/corelib/io/qfileinfo.cpp b/src/corelib/io/qfileinfo.cpp
index 7fcb4154f2..addcd772ab 100644
--- a/src/corelib/io/qfileinfo.cpp
+++ b/src/corelib/io/qfileinfo.cpp
@@ -187,6 +187,8 @@ uint QFileInfoPrivate::getFileFlags(QAbstractFileEngine::FileFlags request) cons
 QDateTime &QFileInfoPrivate::getFileTime(QAbstractFileEngine::FileTime request) const
 {
     Q_ASSERT(fileEngine); // should never be called when using the native FS
+    if (fileTimes.size() != 3)
+        fileTimes.resize(3);
     if (!cache_enabled)
         clearFlags();
     uint cf;
diff --git a/src/corelib/io/qfileinfo_p.h b/src/corelib/io/qfileinfo_p.h
index 1b254f6e85..442e6b5ef0 100644
--- a/src/corelib/io/qfileinfo_p.h
+++ b/src/corelib/io/qfileinfo_p.h
@@ -58,6 +58,7 @@
 #include "qatomic.h"
 #include "qshareddata.h"
 #include "qfilesystemengine_p.h"
+#include "qvector.h"
 
 #include <QtCore/private/qabstractfileengine_p.h>
 #include <QtCore/private/qfilesystementry_p.h>
@@ -152,7 +153,12 @@ public:
     bool cache_enabled : 1;
     mutable uint fileFlags;
     mutable qint64 fileSize;
-    mutable QDateTime fileTimes[3];
+    // ### Qt6: FIXME: This vector is essentially a plain array
+    // mutable QDateTime fileTimes[3], but the array is slower
+    // to initialize than the QVector as QDateTime has a pimpl.
+    // In Qt 6, QDateTime should inline its data members,
+    // and this here can be an array again.
+    mutable QVector<QDateTime> fileTimes;
     inline bool getCachedFlag(uint c) const
     { return cache_enabled ? (cachedFlags & c) : 0; }
     inline void setCachedFlag(uint c) const
diff --git a/src/corelib/tools/qdatetime.h b/src/corelib/tools/qdatetime.h
index d1cc10c877..5c1668033c 100644
--- a/src/corelib/tools/qdatetime.h
+++ b/src/corelib/tools/qdatetime.h
@@ -262,6 +262,10 @@ public:
 private:
     friend class QDateTimePrivate;
     void detach();
+
+    // ### Qt6: Using a private here has high impact on runtime
+    // on users such as QFileInfo. In Qt 6, the data members
+    // should be inlined.
     QExplicitlySharedDataPointer<QDateTimePrivate> d;
 
 #ifndef QT_NO_DATASTREAM