3 files changed, 77 insertions, 5 deletions
diff --git a/src/corelib/text/qstringconverter.cpp b/src/corelib/text/qstringconverter.cpp
index 9322fcd35e..4972bcde4f 100644
--- a/src/corelib/text/qstringconverter.cpp
+++ b/src/corelib/text/qstringconverter.cpp
@@ -1475,12 +1475,25 @@ static bool nameMatch(const char *a, const char *b)
 QStringConverter::QStringConverter(const char *name)
     : iface(nullptr)
 {
+    auto e = encodingForName(name);
+    if (e)
+        iface = encodingInterfaces + int(e.value());
+}
+
+std::optional<QStringConverter::Encoding> QStringConverter::encodingForName(const char *name)
+{
     for (int i = 0; i < LastEncoding + 1; ++i) {
-        if (nameMatch(encodingInterfaces[i].name, name)) {
-            iface = encodingInterfaces + i;
-            break;
-        }
+        if (nameMatch(encodingInterfaces[i].name, name))
+            return QStringConverter::Encoding(i);
     }
+    if (nameMatch(name, "latin1"))
+        return QStringConverter::Latin1;
+    return std::nullopt;
+}
+
+const char *QStringConverter::nameForEncoding(QStringConverter::Encoding e)
+{
+    return encodingInterfaces[int(e)].name;
 }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/text/qstringconverter.h b/src/corelib/text/qstringconverter.h
index 73f9f4f9ba..fe401ecc9e 100644
--- a/src/corelib/text/qstringconverter.h
+++ b/src/corelib/text/qstringconverter.h
@@ -45,6 +45,8 @@
 #include <QtCore/qstringbuilder.h>
 #endif
 
+#include <optional>
+
 QT_BEGIN_NAMESPACE
 
 // work around a compiler bug in GCC 7
@@ -148,7 +150,8 @@ protected:
     QSTRINGCONVERTER_CONSTEXPR QStringConverter(const Interface *i)
         : iface(i)
     {}
-    QStringConverter(const char *name);
+    Q_CORE_EXPORT QStringConverter(const char *name);
+
 
 public:
     bool isValid() const { return iface != nullptr; }
@@ -162,6 +165,9 @@ public:
     const char *name() const
     { return isValid() ? iface->name : nullptr; }
 
+    Q_CORE_EXPORT static std::optional<Encoding> encodingForName(const char *name);
+    Q_CORE_EXPORT static const char *nameForEncoding(Encoding e);
+
 protected:
     const Interface *iface;
     State state;
diff --git a/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp b/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp
index 1419321679..f0e794e910 100644
--- a/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp
+++ b/tests/auto/corelib/text/qstringconverter/tst_qstringconverter.cpp
@@ -59,6 +59,12 @@ private slots:
 
     void utfHeaders_data();
     void utfHeaders();
+
+    void encodingForName_data();
+    void encodingForName();
+
+    void nameForEncoding_data();
+    void nameForEncoding();
 };
 
 void tst_QStringConverter::constructByName()
@@ -1611,6 +1617,53 @@ void tst_QStringConverter::utfHeaders()
     }
 }
 
+void tst_QStringConverter::encodingForName_data()
+{
+    QTest::addColumn<QByteArray>("name");
+    QTest::addColumn<std::optional<QStringConverter::Encoding>>("encoding");
+
+    QTest::newRow("UTF-8") << QByteArray("UTF-8") << std::optional<QStringConverter::Encoding>(QStringConverter::Utf8);
+    QTest::newRow("utf8") << QByteArray("utf8") << std::optional<QStringConverter::Encoding>(QStringConverter::Utf8);
+    QTest::newRow("Utf-8") << QByteArray("Utf-8") << std::optional<QStringConverter::Encoding>(QStringConverter::Utf8);
+    QTest::newRow("UTF-16") << QByteArray("UTF-16") << std::optional<QStringConverter::Encoding>(QStringConverter::Utf16);
+    QTest::newRow("UTF-16le") << QByteArray("UTF-16le") << std::optional<QStringConverter::Encoding>(QStringConverter::Utf16LE);
+    QTest::newRow("ISO-8859-1") << QByteArray("ISO-8859-1") << std::optional<QStringConverter::Encoding>(QStringConverter::Latin1);
+    QTest::newRow("ISO8859-1") << QByteArray("ISO8859-1") << std::optional<QStringConverter::Encoding>(QStringConverter::Latin1);
+    QTest::newRow("iso8859-1") << QByteArray("iso8859-1") << std::optional<QStringConverter::Encoding>(QStringConverter::Latin1);
+    QTest::newRow("latin1") << QByteArray("latin1") << std::optional<QStringConverter::Encoding>(QStringConverter::Latin1);
+    QTest::newRow("latin2") << QByteArray("latin2") << std::optional<QStringConverter::Encoding>();
+    QTest::newRow("latin15") << QByteArray("latin15") << std::optional<QStringConverter::Encoding>();
+}
+
+void tst_QStringConverter::encodingForName()
+{
+    QFETCH(QByteArray, name);
+    QFETCH(std::optional<QStringConverter::Encoding>, encoding);
+
+    auto e = QStringConverter::encodingForName(name);
+    QCOMPARE(e, encoding);
+}
+
+void tst_QStringConverter::nameForEncoding_data()
+{
+    QTest::addColumn<QByteArray>("name");
+    QTest::addColumn<QStringConverter::Encoding>("encoding");
+
+    QTest::newRow("UTF-8") << QByteArray("UTF-8") << QStringConverter::Utf8;
+    QTest::newRow("UTF-16") << QByteArray("UTF-16") << QStringConverter::Utf16;
+    QTest::newRow("UTF-16LE") << QByteArray("UTF-16LE") << QStringConverter::Utf16LE;
+    QTest::newRow("ISO-8859-1") << QByteArray("ISO-8859-1") << QStringConverter::Latin1;
+}
+
+void tst_QStringConverter::nameForEncoding()
+{
+    QFETCH(QByteArray, name);
+    QFETCH(QStringConverter::Encoding, encoding);
+
+    QByteArray n = QStringConverter::nameForEncoding(encoding);
+    QCOMPARE(n, name);
+}
+
 class LoadAndConvert: public QRunnable
 {
 public: