tst_QString/tst_QByteArray: add checks for null-ness

We want to preserve nullness where possible. Test that various ctors
do the right thing when presented with null input.

Pick-to: 6.3
Change-Id: Ia1a1d4fb3c919b4fed2d9b87827815a1b5072c54
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
index ae65b8d27e..b0d9f39b3e 100644
--- a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
+++ b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
@@ -95,6 +95,7 @@ private slots:
     void number_double();
     void number_base_data();
     void number_base();
+    void nullness();
     void blockSizeCalculations();
 
     void resizeAfterFromRawData();
@@ -1362,6 +1363,38 @@ void tst_QByteArray::number_base()
     }
 }
 
+void tst_QByteArray::nullness()
+{
+    {
+        QByteArray ba;
+        QVERIFY(ba.isNull());
+    }
+    {
+        QByteArray ba = nullptr;
+        QVERIFY(ba.isNull());
+    }
+    {
+        const char *ptr = nullptr;
+        QByteArray ba = ptr;
+        QVERIFY(ba.isNull());
+    }
+    {
+        QByteArray ba(nullptr, 0);
+        QVERIFY(ba.isNull());
+    }
+    {
+        const char *ptr = nullptr;
+        QByteArray ba(ptr, 0);
+        QVERIFY(ba.isNull());
+    }
+    {
+        QByteArrayView bav;
+        QVERIFY(bav.isNull());
+        QByteArray ba = bav.toByteArray();
+        QVERIFY(ba.isNull());
+    }
+}
+
 static bool checkSize(qsizetype value, qsizetype min)
 {
     return value >= min && value <= std::numeric_limits<qsizetype>::max();