Add QStringDecoder::decoderForHtml()

Now that QStringConverter can handle non UTF encodings through ICU,
add a way to get a decoder for arbitrary HTML code.

Opposed to QStringConverter::encodingForHtml(), this method will
try to create a valid string decoder also for non unicode codecs.

Pick-to: 6.4
Change-Id: I343584da1b114396c744f482d9b433c9cedcc511
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/src/corelib/kernel/qmimedata.cpp b/src/corelib/kernel/qmimedata.cpp
index 661a30b167..02a86bff37 100644
--- a/src/corelib/kernel/qmimedata.cpp
+++ b/src/corelib/kernel/qmimedata.cpp
@@ -127,10 +127,9 @@ QVariant QMimeDataPrivate::retrieveTypedData(const QString &format, QMetaType ty
             if (ba.isNull())
                 return QVariant();
             if (format == "text/html"_L1) {
-                auto encoding = QStringConverter::encodingForHtml(ba);
-                if (encoding) {
-                    QStringDecoder toUtf16(*encoding);
-                    return QString(toUtf16(ba));
+                QStringDecoder decoder = QStringDecoder::decoderForHtml(ba);
+                if (decoder.isValid()) {
+                    return QString(decoder(ba));
                 }
                 // fall back to utf8
             }