Suppress a broken benchmark comparing QVector to std::vector

The test constructs an ersatz object with which to overwrite a
QVector's internals, but based it on Qt 5's memory layout. Since Qt 6
completely rearranged that memory layout, the test now crashes (or, in
a debug build, trips over an out-of-bounds assertion).

So suppress the test until those who perpetrated it and/or the
reworking of QVector's internals can work out how to fix it.
That way, QA can at least run the benchmark without crashing.

Task-number: QTBUG-95061
Pick-to: 6.2
Change-Id: I0e8c8d58f2002497f6e29d0ad25f840e207704a4
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

2 files changed, 15 insertions, 6 deletions

diff --git a/tests/benchmarks/corelib/tools/qvector/main.cpp b/tests/benchmarks/corelib/tools/qvector/main.cpp
index b090c04480..6d1354cb6a 100644
--- a/tests/benchmarks/corelib/tools/qvector/main.cpp
+++ b/tests/benchmarks/corelib/tools/qvector/main.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the test suite of the Qt Toolkit.
@@ -175,6 +175,16 @@ sys     0m0.008s
 
 
 #define TEST_RETURN 1
+#if TEST_RETURN
+/* QRawVector::mutateToVector() hacks a semblance of a Qt 5 QVector.
+
+   However, Qt 6's QVector is Qt 6's QList and completely different in internal
+   layout.  The QTypedArrayData inside it is also completely rearranged.  Until
+   QRawVector can be rewritten to do whatever it's supposed to do in a
+   Qt6-compatible way, this test is suppressed, see QTBUG-95061.
+*/
+#define TEST_RAW 0
+#endif
 
 // For some reason, both 'plain' and '-callgrind' create strange results
 // (like varying instruction count for the same assembly code)
@@ -218,9 +228,9 @@ private slots:
     void qrawvector_separator() { qWarning() << "QRawVector results: "; }
     void qrawvector_const_read_access();
     void qrawvector_mutable_read_access();
-    #ifdef TEST_RETURN
+#if TEST_RAW
     void qrawvector_fill_and_return();
-    #endif
+#endif
 };
 
 const int N = 1000000;
@@ -321,9 +331,7 @@ void tst_QVector::qvector_pop_back()
     }
 }
 
-
-
-#ifdef TEST_RETURN
+#if TEST_RAW
 extern QVector<double> qrawvector_fill_and_return_helper();
 
 void tst_QVector::qrawvector_fill_and_return()
diff --git a/tests/benchmarks/corelib/tools/qvector/qrawvector.h b/tests/benchmarks/corelib/tools/qvector/qrawvector.h
index 1f615f6e69..3d827c7921 100644
--- a/tests/benchmarks/corelib/tools/qvector/qrawvector.h
+++ b/tests/benchmarks/corelib/tools/qvector/qrawvector.h
@@ -217,6 +217,7 @@ private:
 public:
     QVector<T> mutateToVector()
     {
+        Q_ASSERT(!"Fix QTBUG-95061 before calling this; it is broken beyond repair");
         Data *d = toBase(m_begin);
         d->ref.initializeOwned();
         d->alloc = m_alloc;