QString: preserve embedded NULs when converting from QByteArray

Unearthed an off-by-one error in a QByteArray::fromRawData() call in
tst_qtextdocumentfragment. Fixed by porting to QStringLiteral.

[ChangeLog][Important Behavior Changes] All conversions from QByteArray
to QString now preserve embedded NULs. This is done in order to provide a
faster conversion from QByteArray to QString that does not involve a call to
strlen. If you need the old behavior, convert from QByteArray::constData()
instead. If you are porting from Qt 4, we suggest to make your source compile
with QT_NO_CAST_FROM_BYTEARRAY before porting to Qt 5.

Change-Id: Ibca40f503920fee6f3a5f0d74a04b38b8849796f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 23 insertions, 58 deletions

diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index 8ce3d51b2c..41f7b1b084 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -84,7 +84,7 @@ class QLatin1String
 public:
     Q_DECL_CONSTEXPR inline explicit QLatin1String(const char *s) : m_size(s ? int(strlen(s)) : 0), m_data(s) {}
     Q_DECL_CONSTEXPR inline explicit QLatin1String(const char *s, int sz) : m_size(sz), m_data(s) {}
-    inline explicit QLatin1String(const QByteArray &s) : m_size(int(qstrnlen(s.constData(), s.size()))), m_data(s.constData()) {}
+    inline explicit QLatin1String(const QByteArray &s) : m_size(s.size()), m_data(s.constData()) {}
 
     inline const char *latin1() const { return m_data; }
     inline int size() const { return m_size; }
@@ -534,11 +534,11 @@ public:
         return fromLocal8Bit_helper(str, (str && size == -1) ? int(strlen(str)) : size);
     }
     static inline QString fromLatin1(const QByteArray &str)
-    { return str.isNull() ? QString() : fromLatin1(str.data(), qstrnlen(str.constData(), str.size())); }
+    { return str.isNull() ? QString() : fromLatin1(str.data(), str.size()); }
     static inline QString fromUtf8(const QByteArray &str)
-    { return str.isNull() ? QString() : fromUtf8(str.data(), qstrnlen(str.constData(), str.size())); }
+    { return str.isNull() ? QString() : fromUtf8(str.data(), str.size()); }
     static inline QString fromLocal8Bit(const QByteArray &str)
-    { return str.isNull() ? QString() : fromLocal8Bit(str.data(), qstrnlen(str.constData(), str.size())); }
+    { return str.isNull() ? QString() : fromLocal8Bit(str.data(), str.size()); }
     static QString fromUtf16(const ushort *, int size = -1);
     static QString fromUcs4(const uint *, int size = -1);
     static QString fromRawData(const QChar *, int size);
@@ -650,7 +650,7 @@ public:
         : d(fromAscii_helper(ch, ch ? int(strlen(ch)) : -1))
     {}
     inline QT_ASCII_CAST_WARN QString(const QByteArray &a)
-        : d(fromAscii_helper(a.constData(), qstrnlen(a.constData(), a.size())))
+        : d(fromAscii_helper(a.constData(), a.size()))
     {}
     inline QT_ASCII_CAST_WARN QString &operator=(const char *ch)
     { return (*this = fromUtf8(ch)); }
@@ -1211,30 +1211,30 @@ inline QT_ASCII_CAST_WARN bool QLatin1String::operator>=(const QByteArray &s) co
 { return QString::fromUtf8(s) <= *this; }
 
 inline QT_ASCII_CAST_WARN bool QString::operator==(const QByteArray &s) const
-{ return QString::compare_helper(constData(), size(), s.constData(), qstrnlen(s.constData(), s.size())) == 0; }
+{ return QString::compare_helper(constData(), size(), s.constData(), s.size()) == 0; }
 inline QT_ASCII_CAST_WARN bool QString::operator!=(const QByteArray &s) const
-{ return QString::compare_helper(constData(), size(), s.constData(), qstrnlen(s.constData(), s.size())) != 0; }
+{ return QString::compare_helper(constData(), size(), s.constData(), s.size()) != 0; }
 inline QT_ASCII_CAST_WARN bool QString::operator<(const QByteArray &s) const
-{ return QString::compare_helper(constData(), size(), s.constData(), qstrnlen(s.constData(), s.size())) < 0; }
+{ return QString::compare_helper(constData(), size(), s.constData(), s.size()) < 0; }
 inline QT_ASCII_CAST_WARN bool QString::operator>(const QByteArray &s) const
-{ return QString::compare_helper(constData(), size(), s.constData(), qstrnlen(s.constData(), s.size())) > 0; }
+{ return QString::compare_helper(constData(), size(), s.constData(), s.size()) > 0; }
 inline QT_ASCII_CAST_WARN bool QString::operator<=(const QByteArray &s) const
-{ return QString::compare_helper(constData(), size(), s.constData(), qstrnlen(s.constData(), s.size())) <= 0; }
+{ return QString::compare_helper(constData(), size(), s.constData(), s.size()) <= 0; }
 inline QT_ASCII_CAST_WARN bool QString::operator>=(const QByteArray &s) const
-{ return QString::compare_helper(constData(), size(), s.constData(), qstrnlen(s.constData(), s.size())) >= 0; }
+{ return QString::compare_helper(constData(), size(), s.constData(), s.size()) >= 0; }
 
 inline bool QByteArray::operator==(const QString &s) const
-{ return QString::compare_helper(s.constData(), s.size(), constData(), qstrnlen(constData(), size())) == 0; }
+{ return QString::compare_helper(s.constData(), s.size(), constData(), size()) == 0; }
 inline bool QByteArray::operator!=(const QString &s) const
-{ return QString::compare_helper(s.constData(), s.size(), constData(), qstrnlen(constData(), size())) != 0; }
+{ return QString::compare_helper(s.constData(), s.size(), constData(), size()) != 0; }
 inline bool QByteArray::operator<(const QString &s) const
-{ return QString::compare_helper(s.constData(), s.size(), constData(), qstrnlen(constData(), size())) < 0; }
+{ return QString::compare_helper(s.constData(), s.size(), constData(), size()) < 0; }
 inline bool QByteArray::operator>(const QString &s) const
-{ return QString::compare_helper(s.constData(), s.size(), constData(), qstrnlen(constData(), size())) > 0; }
+{ return QString::compare_helper(s.constData(), s.size(), constData(), size()) > 0; }
 inline bool QByteArray::operator<=(const QString &s) const
-{ return QString::compare_helper(s.constData(), s.size(), constData(), qstrnlen(constData(), size())) <= 0; }
+{ return QString::compare_helper(s.constData(), s.size(), constData(), size()) <= 0; }
 inline bool QByteArray::operator>=(const QString &s) const
-{ return QString::compare_helper(s.constData(), s.size(), constData(), qstrnlen(constData(), size())) >= 0; }
+{ return QString::compare_helper(s.constData(), s.size(), constData(), size()) >= 0; }
 #endif // !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
 
 #ifndef QT_NO_CAST_TO_ASCII
diff --git a/tests/auto/corelib/tools/qstring/tst_qstring.cpp b/tests/auto/corelib/tools/qstring/tst_qstring.cpp
index c3dbb26587..647a75ceb2 100644
--- a/tests/auto/corelib/tools/qstring/tst_qstring.cpp
+++ b/tests/auto/corelib/tools/qstring/tst_qstring.cpp
@@ -828,7 +828,7 @@ void tst_QString::constructorQByteArray_data()
     ba1[5] = 'e';
     ba1[6] = 'f';
 
-    QTest::newRow( "2" ) << ba1 << QString("abc");
+    QTest::newRow( "2" ) << ba1 << QStringLiteral("abc\0def");
 
     QTest::newRow( "3" ) << QByteArray::fromRawData("abcd", 3) << QString("abc");
     QTest::newRow( "4" ) << QByteArray("\xc3\xa9") << QString("\xc3\xa9");
@@ -849,12 +849,6 @@ void tst_QString::constructorQByteArray()
     QCOMPARE( strBA, expected );
 
     // test operator= too
-    if (src.constData()[src.length()] == '\0') {
-        str1.clear();
-        str1 = src.constData();
-        QCOMPARE( str1, expected );
-    }
-
     strBA.clear();
     strBA = src;
     QCOMPARE( strBA, expected );
@@ -2177,14 +2171,6 @@ void tst_QString::append_bytearray()
 
         QTEST( str, "res" );
     }
-
-    QFETCH( QByteArray, ba );
-    if (ba.constData()[ba.length()] == '\0') {
-        QFETCH( QString, str );
-
-        str.append(ba.constData());
-        QTEST( str, "res" );
-    }
 }
 
 void tst_QString::operator_pluseq_bytearray_data()
@@ -2210,14 +2196,6 @@ void tst_QString::operator_pluseq_bytearray()
 
         QTEST( str, "res" );
     }
-
-    QFETCH( QByteArray, ba );
-    if (ba.constData()[ba.length()] == '\0') {
-        QFETCH( QString, str );
-
-        str += ba.constData();
-        QTEST( str, "res" );
-    }
 }
 
 void tst_QString::operator_eqeq_bytearray_data()
@@ -2232,11 +2210,6 @@ void tst_QString::operator_eqeq_bytearray()
 
     QVERIFY(expected == src);
     QVERIFY(!(expected != src));
-
-    if (src.constData()[src.length()] == '\0') {
-        QVERIFY(expected == src.constData());
-        QVERIFY(!(expected != src.constData()));
-    }
 }
 
 void tst_QString::swap()
@@ -2271,7 +2244,7 @@ void tst_QString::prepend_bytearray_data()
     // byte array with only a 0
     ba.resize( 1 );
     ba[0] = 0;
-    QTest::newRow( "emptyString" ) << QString("foobar ") << ba << QString("foobar ");
+    QTest::newRow( "emptyString" ) << QString("foobar ") << ba << QStringLiteral("\0foobar ");
 
     // empty byte array
     ba.resize( 0 );
@@ -2301,14 +2274,6 @@ void tst_QString::prepend_bytearray()
 
         QTEST( str, "res" );
     }
-
-    QFETCH( QByteArray, ba );
-    if (ba.constData()[ba.length()] == '\0') {
-        QFETCH( QString, str );
-
-        str.prepend(ba.constData());
-        QTEST( str, "res" );
-    }
 }
 
 void tst_QString::replace_uint_uint()
diff --git a/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp b/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp
index 8f0d306cba..f6bd09958e 100644
--- a/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp
+++ b/tests/auto/gui/text/qtextdocumentfragment/tst_qtextdocumentfragment.cpp
@@ -1378,8 +1378,8 @@ void tst_QTextDocumentFragment::html_listStart1()
 {
     // don't create a block for the <ul> element, even if there's some whitespace between
     // it and the <li>
-    const char html[] = "<ul>        <li>list item</li><ul>";
-    cursor.insertFragment(QTextDocumentFragment::fromHtml(QByteArray::fromRawData(html, sizeof(html) / sizeof(html[0]))));
+    const QString html = QStringLiteral("<ul>        <li>list item</li><ul>");
+    cursor.insertFragment(QTextDocumentFragment::fromHtml(html));
 
     QCOMPARE(doc->blockCount(), 1);
 }
@@ -1387,8 +1387,8 @@ void tst_QTextDocumentFragment::html_listStart1()
 void tst_QTextDocumentFragment::html_listStart2()
 {
     // unlike with html_listStart1 we want a block showing the 'buggy' text here
-    const char html[] = "<ul>buggy, but text should appear<li>list item</li><ul>";
-    cursor.insertFragment(QTextDocumentFragment::fromHtml(QByteArray::fromRawData(html, sizeof(html) / sizeof(html[0]))));
+    const QString html = QStringLiteral("<ul>buggy, but text should appear<li>list item</li><ul>");
+    cursor.insertFragment(QTextDocumentFragment::fromHtml(html));
 
     QCOMPARE(doc->blockCount(), 2);
 }