Get rid of shared null for QByteArray, QString and QVector

As a side effect, data() can now return a nullptr. This
has the potential to cause crashes in existig code. To work
around this, return an empty string from QString::data()
and QByteArray::data() for now.

For Qt 6 (and once all our internal issues are fixed), data()
will by default return a nullptr for a null QString, but we'll
offer a #define to enable backwards compatible behavior.

Change-Id: I4f66d97ff1dce3eb99a239f1eab9106fa9b1741a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
index 73d9f8e765..940865b98e 100644
--- a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
+++ b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
@@ -2277,7 +2277,7 @@ void tst_QByteArray::literals()
     QVERIFY(str.length() == 4);
     QCOMPARE(str.capacity(), 0);
     QVERIFY(str == "abcd");
-    QVERIFY(str.data_ptr()->isStatic());
+    QVERIFY(!str.data_ptr()->isMutable());
 
     const char *s = str.constData();
     QByteArray str2 = str;