Mark QUrl::{to,from}Punycode as deprecated since 5.0

These functions are now aliases to {to,from}Ace, which are usually
what you want. The original functions from Qt 4.0 had the wrong
semantics and wrong name. The new ones from Qt 4.2 execute the ACE
processing from IDNA (specifically, the ToASCII and ToUnicode
operations described in the RFC).

But so as not to be without tests, export the tests in unit testing
environment and test the punycode roundtrip. Note that the
tst_QUrl::idna_test_suite test tests *only* the Punycode roundtrip,
not the nameprepping.

Change-Id: I9b95b4bd07b4425344a5c6ef5cce7cfcb9846d3e
Reviewed-by: João Abecasis <joao.abecasis@nokia.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
Reviewed-by: David Faure <faure@kde.org>

2 files changed, 86 insertions, 87 deletions

diff --git a/src/corelib/io/qurl.cpp b/src/corelib/io/qurl.cpp
index 4b9e4d6782..fe8255118c 100644
--- a/src/corelib/io/qurl.cpp
+++ b/src/corelib/io/qurl.cpp
@@ -2942,15 +2942,13 @@ static bool isBidirectionalL(uint uc)
 
 #ifdef QT_BUILD_INTERNAL
 // export for tst_qurl.cpp
-Q_AUTOTEST_EXPORT void qt_nameprep(QString *source, int from);
-Q_AUTOTEST_EXPORT bool qt_check_std3rules(const QChar *uc, int len);
+#define Q_URLTEST_EXPORT Q_AUTOTEST_EXPORT
 #else
 // non-test build, keep the symbols for ourselves
-static void qt_nameprep(QString *source, int from);
-static bool qt_check_std3rules(const QChar *uc, int len);
+#define Q_URLTEST_EXPORT static
 #endif
 
-void qt_nameprep(QString *source, int from)
+Q_URLTEST_EXPORT void qt_nameprep(QString *source, int from)
 {
     QChar *src = source->data(); // causes a detach, so we're sure the only one using it
     QChar *out = src + from;
@@ -3041,7 +3039,7 @@ void qt_nameprep(QString *source, int from)
     }
 }
 
-bool qt_check_std3rules(const QChar *uc, int len)
+Q_URLTEST_EXPORT bool qt_check_std3rules(const QChar *uc, int len)
 {
     if (len > 63)
         return false;
@@ -3108,7 +3106,7 @@ static inline void appendEncode(QString* output, uint& delta, uint& bias, uint&
     ++h;
 }
 
-static void toPunycodeHelper(const QChar *s, int ucLength, QString *output)
+Q_URLTEST_EXPORT void qt_punycodeEncoder(const QChar *s, int ucLength, QString *output)
 {
     uint n = initial_n;
     uint delta = 0;
@@ -3194,6 +3192,76 @@ static void toPunycodeHelper(const QChar *s, int ucLength, QString *output)
     return;
 }
 
+Q_URLTEST_EXPORT QString qt_punycodeDecoder(const QString &pc)
+{
+    uint n = initial_n;
+    uint i = 0;
+    uint bias = initial_bias;
+
+    // strip any ACE prefix
+    int start = pc.startsWith(QLatin1String("xn--")) ? 4 : 0;
+    if (!start)
+        return pc;
+
+    // find the last delimiter character '-' in the input array. copy
+    // all data before this delimiter directly to the output array.
+    int delimiterPos = pc.lastIndexOf(QChar(0x2d));
+    QString output = delimiterPos < 4 ?
+                     QString() : pc.mid(start, delimiterPos - start);
+
+    // if a delimiter was found, skip to the position after it;
+    // otherwise start at the front of the input string. everything
+    // before the delimiter is assumed to be basic code points.
+    uint cnt = delimiterPos + 1;
+
+    // loop through the rest of the input string, inserting non-basic
+    // characters into output as we go.
+    while (cnt < (uint) pc.size()) {
+        uint oldi = i;
+        uint w = 1;
+
+        // find the next index for inserting a non-basic character.
+        for (uint k = base; cnt < (uint) pc.size(); k += base) {
+            // grab a character from the punycode input and find its
+            // delta digit (each digit code is part of the
+            // variable-length integer delta)
+            uint digit = pc.at(cnt++).unicode();
+            if (digit - 48 < 10) digit -= 22;
+            else if (digit - 65 < 26) digit -= 65;
+            else if (digit - 97 < 26) digit -= 97;
+            else digit = base;
+
+            // reject out of range digits
+            if (digit >= base || digit > (Q_MAXINT - i) / w)
+                return QStringLiteral("");
+
+            i += (digit * w);
+
+            // detect threshold to stop reading delta digits
+            uint t;
+            if (k <= bias) t = tmin;
+            else if (k >= bias + tmax) t = tmax;
+            else t = k - bias;
+            if (digit < t) break;
+
+            w *= (base - t);
+        }
+
+        // find new bias and calculate the next non-basic code
+        // character.
+        bias = adapt(i - oldi, output.length() + 1, oldi == 0);
+        n += i / (output.length() + 1);
+
+        // allow the deltas to wrap around
+        i %= (output.length() + 1);
+
+        // insert the character n at position i
+        output.insert((uint) i, QChar((ushort) n));
+        ++i;
+    }
+
+    return output;
+}
 
 static const char * const idn_whitelist[] = {
     "ac", "ar", "at",
@@ -3378,11 +3446,11 @@ static QString qt_ACE_do(const QString &domain, AceOperation op)
             aceForm.resize(0);
             if (toReserve > aceForm.capacity())
                 aceForm.reserve(toReserve);
-            toPunycodeHelper(result.constData() + prevLen, result.size() - prevLen, &aceForm);
+            qt_punycodeEncoder(result.constData() + prevLen, result.size() - prevLen, &aceForm);
 
             // We use resize()+memcpy() here because we're overwriting the data we've copied
             if (isIdnEnabled) {
-                QString tmp = QUrl::fromPunycode(aceForm.toLatin1());
+                QString tmp = qt_punycodeDecoder(aceForm);
                 if (tmp.isEmpty())
                     return QString(); // shouldn't happen, since we've just punycode-encoded it
                 result.resize(prevLen + tmp.size());
@@ -5828,6 +5896,7 @@ QByteArray QUrl::toPercentEncoding(const QString &input, const QByteArray &exclu
 }
 
 /*!
+    \fn QByteArray QUrl::toPunycode(const QString &uc)
     \obsolete
     Returns a \a uc in Punycode encoding.
 
@@ -5835,14 +5904,9 @@ QByteArray QUrl::toPercentEncoding(const QString &input, const QByteArray &exclu
     names, as defined in RFC3492. If you want to convert a domain name from
     Unicode to its ASCII-compatible representation, use toAce().
 */
-QByteArray QUrl::toPunycode(const QString &uc)
-{
-    QString output;
-    toPunycodeHelper(uc.constData(), uc.size(), &output);
-    return output.toLatin1();
-}
 
 /*!
+    \fn QString QUrl::fromPunycode(const QByteArray &pc)
     \obsolete
     Returns the Punycode decoded representation of \a pc.
 
@@ -5851,76 +5915,6 @@ QByteArray QUrl::toPunycode(const QString &uc)
     its ASCII-compatible encoding to the Unicode representation, use
     fromAce().
 */
-QString QUrl::fromPunycode(const QByteArray &pc)
-{
-    uint n = initial_n;
-    uint i = 0;
-    uint bias = initial_bias;
-
-    // strip any ACE prefix
-    int start = pc.startsWith("xn--") ? 4 : 0;
-    if (!start)
-        return QString::fromLatin1(pc);
-
-    // find the last delimiter character '-' in the input array. copy
-    // all data before this delimiter directly to the output array.
-    int delimiterPos = pc.lastIndexOf(0x2d);
-    QString output = delimiterPos < 4 ?
-                     QString() : QString::fromLatin1(pc.constData() + start, delimiterPos - start);
-
-    // if a delimiter was found, skip to the position after it;
-    // otherwise start at the front of the input string. everything
-    // before the delimiter is assumed to be basic code points.
-    uint cnt = delimiterPos + 1;
-
-    // loop through the rest of the input string, inserting non-basic
-    // characters into output as we go.
-    while (cnt < (uint) pc.size()) {
-        uint oldi = i;
-        uint w = 1;
-
-        // find the next index for inserting a non-basic character.
-        for (uint k = base; cnt < (uint) pc.size(); k += base) {
-            // grab a character from the punycode input and find its
-            // delta digit (each digit code is part of the
-            // variable-length integer delta)
-            uint digit = pc.at(cnt++);
-            if (digit - 48 < 10) digit -= 22;
-            else if (digit - 65 < 26) digit -= 65;
-            else if (digit - 97 < 26) digit -= 97;
-            else digit = base;
-
-            // reject out of range digits
-            if (digit >= base || digit > (Q_MAXINT - i) / w)
-                return QLatin1String("");
-
-            i += (digit * w);
-
-            // detect threshold to stop reading delta digits
-            uint t;
-            if (k <= bias) t = tmin;
-            else if (k >= bias + tmax) t = tmax;
-            else t = k - bias;
-            if (digit < t) break;
-
-            w *= (base - t);
-        }
-
-        // find new bias and calculate the next non-basic code
-        // character.
-        bias = adapt(i - oldi, output.length() + 1, oldi == 0);
-        n += i / (output.length() + 1);
-
-        // allow the deltas to wrap around
-        i %= (output.length() + 1);
-
-        // insert the character n at position i
-        output.insert((uint) i, QChar((ushort) n));
-        ++i;
-    }
-
-    return output;
-}
 
 /*!
     \since 4.2
diff --git a/src/corelib/io/qurl.h b/src/corelib/io/qurl.h
index 33fac9db57..7c6cc29618 100644
--- a/src/corelib/io/qurl.h
+++ b/src/corelib/io/qurl.h
@@ -201,8 +201,13 @@ public:
     static QByteArray toPercentEncoding(const QString &,
                                         const QByteArray &exclude = QByteArray(),
                                         const QByteArray &include = QByteArray());
-    static QString fromPunycode(const QByteArray &);
-    static QByteArray toPunycode(const QString &);
+#if QT_DEPRECATED_SINCE(5,0)
+    QT_DEPRECATED static QString fromPunycode(const QByteArray &punycode)
+    { return fromAce(punycode); }
+    QT_DEPRECATED static QByteArray toPunycode(const QString &string)
+    { return toAce(string); }
+#endif
+
     static QString fromAce(const QByteArray &);
     static QByteArray toAce(const QString &);
     static QStringList idnWhitelist();