QTextStream: Fix logical error in setEncoding

We only want to enable writing BOM if we have _not_ started
writing.

Fixes: QTBUG-106279
Pick-to: 6.2 6.3.2 6.4 6.4.0
Change-Id: Ibcbc101b931615fddb2507f01307bf9619772d7b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/tests/auto/corelib/serialization/qtextstream/tst_qtextstream.cpp b/tests/auto/corelib/serialization/qtextstream/tst_qtextstream.cpp
index 6d80efe956..cf1049ab4f 100644
--- a/tests/auto/corelib/serialization/qtextstream/tst_qtextstream.cpp
+++ b/tests/auto/corelib/serialization/qtextstream/tst_qtextstream.cpp
@@ -12,6 +12,7 @@
 #include <QDebug>
 #include <QElapsedTimer>
 #include <QFile>
+#include <QTemporaryFile>
 #include <QStringConverter>
 #include <QTcpSocket>
 #include <QTemporaryDir>
@@ -202,6 +203,9 @@ private slots:
 
     void textModeOnEmptyRead();
 
+    void autodetectUnicode_data();
+    void autodetectUnicode();
+
 private:
     void generateLineData(bool for_QString);
     void generateAllData(bool for_QString);
@@ -3043,6 +3047,57 @@ void tst_QTextStream::textModeOnEmptyRead()
     QVERIFY(file.isTextModeEnabled());
 }
 
+void tst_QTextStream::autodetectUnicode_data()
+{
+    QTest::addColumn<QStringConverter::Encoding>("encoding");
+    QTest::newRow("Utf8") << QStringConverter::Utf8;
+    QTest::newRow("Utf16BE") << QStringConverter::Utf16BE;
+    QTest::newRow("Utf16LE") << QStringConverter::Utf16LE;
+    QTest::newRow("Utf32BE") << QStringConverter::Utf32BE;
+    QTest::newRow("Utf32LE") << QStringConverter::Utf32LE;
+}
+
+void tst_QTextStream::autodetectUnicode()
+{
+    QFETCH(QStringConverter::Encoding, encoding);
+
+    QTemporaryFile file;
+    QVERIFY(file.open());
+
+    QString original("HelloWorld👋");
+
+    {
+        QTextStream out(&file);
+        out.setGenerateByteOrderMark(true);
+        out.setEncoding(encoding);
+        out << original;
+    }
+    file.seek(0);
+    {
+        QTextStream in(&file);
+        QString actual;
+        in >> actual;
+        QCOMPARE(actual, original);
+        QCOMPARE(in.encoding(), encoding);
+    }
+    file.seek(0);
+    // Again, but change order of calls to QTextStream...
+    {
+        QTextStream out(&file);
+        out.setEncoding(encoding);
+        out.setGenerateByteOrderMark(true);
+        out << original;
+    }
+    file.seek(0);
+    {
+        QTextStream in(&file);
+        QString actual;
+        in >> actual;
+        QCOMPARE(actual, original);
+        QCOMPARE(in.encoding(), encoding);
+    }
+}
+
 
 // ------------------------------------------------------------------------------