diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp
index 42921e99d76..4628c55ce50 100644
--- a/src/corelib/text/qbytearray.cpp
+++ b/src/corelib/text/qbytearray.cpp
@@ -1342,14 +1342,7 @@ QByteArray &QByteArray::operator=(const char *str)
     } else if (!*str) {
         d = DataPointer::fromRawData(&_empty, 0);
     } else {
-        const qsizetype len = qsizetype(strlen(str));
-        const auto capacityAtEnd = d->allocatedCapacity() - d.freeSpaceAtBegin();
-        if (d->needsDetach() || len > capacityAtEnd
-                || (len < size() && len < (capacityAtEnd >> 1)))
-            // ### inefficient! reallocData() does copy the old data and we then overwrite it in the next line
-            reallocData(len, QArrayData::KeepSize);
-        memcpy(d.data(), str, len + 1); // include null terminator
-        d.size = len;
+        assign(str);
     }
     return *this;
 }
diff --git a/tests/benchmarks/corelib/text/qbytearray/tst_bench_qbytearray.cpp b/tests/benchmarks/corelib/text/qbytearray/tst_bench_qbytearray.cpp
index 05e20645d70..5a8008a7eff 100644
--- a/tests/benchmarks/corelib/text/qbytearray/tst_bench_qbytearray.cpp
+++ b/tests/benchmarks/corelib/text/qbytearray/tst_bench_qbytearray.cpp
@@ -31,6 +31,9 @@ private slots:
 
     void toPercentEncoding_data();
     void toPercentEncoding();
+
+    void operator_assign_char();
+    void operator_assign_char_data();
 };
 
 void tst_QByteArray::initTestCase()
@@ -353,6 +356,38 @@ void tst_QByteArray::toPercentEncoding()
     QTEST(encoded, "expected");
 }
 
+void tst_QByteArray::operator_assign_char()
+{
+    QFETCH(QByteArray, data);
+    QString str(data.size(), Qt::Uninitialized);
+
+    const char *tdata = data.constData();
+    QBENCHMARK {
+        str.operator=(tdata);
+    }
+}
+
+void tst_QByteArray::operator_assign_char_data()
+{
+    QTest::addColumn<QByteArray>("data");
+
+    QByteArray data;
+    data.fill('a', 5);
+    QTest::newRow("length: 5") << data;
+    data.fill('b', 10);
+    QTest::newRow("length: 10") << data;
+    data.fill('c', 20);
+    QTest::newRow("length: 20") << data;
+    data.fill('d', 50);
+    QTest::newRow("length: 50") << data;
+    data.fill('e', 100);
+    QTest::newRow("length: 100") << data;
+    data.fill('f', 500);
+    QTest::newRow("length: 500") << data;
+    data.fill('g', 1'000);
+    QTest::newRow("length: 1'000") << data;
+}
+
 QTEST_MAIN(tst_QByteArray)
 
 #include "tst_bench_qbytearray.moc"