Q(Static)ByteArrayMatcher: manage indexIn() overloads

Unlike QString and QStringView, QByteArrayView and QByteArray don't
overload well.

Solve the overload issue the usual way: by making the QByteArray one a
Q_WEAK_OVERLOAD. This is trivial for QStaticByteArrayMatcher, which
isn't exported, but require QT_REMOVED_SINCE magic for
QByteArrayMatcher, which is.

The additional const char* overload has shielded us from the worst
fall-out so far, it seems, but it makes for a truly horrible overload
set:

    matcher.indexIn(str, 3);

Q: Is the 3 here the length of the haystack or the value of the from
parameter?

A: It depends on decltype(str)!

If the (const char*, qsizetype, qsizetype=0) overload is the better
match, then 3 limits the haystack's length.

If, otoh, the (QByteArray(View), qsizetype) overload is the better
match, then it's the value of the from parameter.

As if this wasn't bad enough, QByteArray implcitly converts to const
char* by default!

A follow-up patch will therefore deprecate the (ptr, size) overloads,
so we de-inline the QByteArrayView ones to avoid having to touch the
implementation once more.

Found during 6.3 API review.

Pick-to: 6.3
Change-Id: I9640e0bdd298d651511adebcc85f314db9221d34
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/corelib/compat/removed_api.cpp

@@ -75,6 +75,11 @@ int QStaticByteArrayMatcherBase::indexOfIn(const char *h, uint hl, const char *n
 
 # endif // QT_POINTER_SIZE != 4
 
+qsizetype QByteArrayMatcher::indexIn(const QByteArray &ba, qsizetype from) const
+{
+    return indexIn(QByteArrayView{ba}, from); // ba.isNull() may be significant, so don't ignore it!
+}
+
 #include "tools/qcryptographichash.h"
 
 void QCryptographicHash::addData(const QByteArray &data)

src/corelib/text/qbytearraymatcher.cpp

@@ -205,21 +205,6 @@ void QByteArrayMatcher::setPattern(const QByteArray &pattern)
     bm_init_skiptable(p.p, p.l, p.q_skiptable);
 }
 
-/*!
-    Searches the byte array \a ba, from byte position \a from (default
-    0, i.e. from the first byte), for the byte array pattern() that
-    was set in the constructor or in the most recent call to
-    setPattern(). Returns the position where the pattern() matched in
-    \a ba, or -1 if no match was found.
-*/
-qsizetype QByteArrayMatcher::indexIn(const QByteArray &ba, qsizetype from) const
-{
-    if (from < 0)
-        from = 0;
-    return bm_find(reinterpret_cast<const uchar *>(ba.constData()), ba.size(), from,
-                   p.p, p.l, p.q_skiptable);
-}
-
 /*!
     Searches the char string \a str, which has length \a len, from
     byte position \a from (default 0, i.e. from the first byte), for
@@ -246,6 +231,13 @@ qsizetype QByteArrayMatcher::indexIn(const char *str, qsizetype len, qsizetype f
     setPattern(). Returns the position where the pattern() matched in
     \a data, or -1 if no match was found.
 */
+qsizetype QByteArrayMatcher::indexIn(QByteArrayView data, qsizetype from) const
+{
+    if (from < 0)
+        from = 0;
+    return bm_find(reinterpret_cast<const uchar *>(data.data()), data.size(), from,
+                   p.p, p.l, p.q_skiptable);
+}
 
 /*!
     \fn QByteArray QByteArrayMatcher::pattern() const

src/corelib/text/qbytearraymatcher.h

@@ -65,12 +65,15 @@ public:
 
     void setPattern(const QByteArray &pattern);
 
+#if QT_REMOVED_SINCE(6, 3)
     qsizetype indexIn(const QByteArray &ba, qsizetype from = 0) const;
+#else
+    Q_WEAK_OVERLOAD
+    qsizetype indexIn(const QByteArray &ba, qsizetype from = 0) const
+    { return indexIn(QByteArrayView{ba}, from); }
+#endif
     qsizetype indexIn(const char *str, qsizetype len, qsizetype from = 0) const;
-    qsizetype indexIn(QByteArrayView data, qsizetype from = 0) const
+    qsizetype indexIn(QByteArrayView data, qsizetype from = 0) const;
-    {
-        return indexIn(data.data(), data.size(), from);
-    }
     inline QByteArray pattern() const
     {
         if (q_pattern.isNull())
@@ -162,10 +165,13 @@ public:
             m_pattern[i] = patternToMatch[i];
     }
 
+    Q_WEAK_OVERLOAD
     qsizetype indexIn(const QByteArray &haystack, qsizetype from = 0) const noexcept
     { return this->indexOfIn(m_pattern, N - 1, haystack.data(), haystack.size(), from); }
     qsizetype indexIn(const char *haystack, qsizetype hlen, qsizetype from = 0) const noexcept
     { return this->indexOfIn(m_pattern, N - 1, haystack, hlen, from); }
+    qsizetype indexIn(QByteArrayView haystack, qsizetype from = 0) const noexcept
+    { return this->indexOfIn(m_pattern, N - 1, haystack.data(), haystack.size(), from); }
 
     QByteArray pattern() const { return QByteArray(m_pattern, qsizetype(N - 1)); }
 };

tests/auto/corelib/text/qbytearraymatcher/tst_qbytearraymatcher.cpp

@@ -48,12 +48,46 @@ class tst_QByteArrayMatcher : public QObject
     Q_OBJECT
 
 private slots:
+    void overloads();
     void interface();
     void indexIn();
     void staticByteArrayMatcher();
     void haystacksWithMoreThan4GiBWork();
 };
 
+void tst_QByteArrayMatcher::overloads()
+{
+    QByteArray hello = QByteArrayLiteral("hello");
+    QByteArray hello2 = hello.repeated(2);
+    {
+        QByteArrayMatcher m("hello");
+        QCOMPARE(m.pattern(), "hello");
+        QCOMPARE(m.indexIn("hello"), 0);
+    }
+    {
+        QByteArrayMatcher m("hello", qsizetype(3));
+        QCOMPARE(m.pattern(), "hel");
+        QCOMPARE(m.indexIn("hellohello", qsizetype(2)), -1); // haystack is "he", not: from is 2
+        QCOMPARE(m.indexIn("hellohello", qsizetype(3)), 0); // haystack is "hel", not: from is 3
+    }
+    {
+        QByteArrayMatcher m(hello);
+        QCOMPARE(m.pattern(), "hello");
+        QCOMPARE(m.indexIn(hello), 0);
+        QCOMPARE(m.indexIn(hello2, qsizetype(1)), hello.size());
+    }
+    {
+        QStaticByteArrayMatcher m("hel");
+        QCOMPARE(m.pattern(), "hel");
+        QCOMPARE(m.indexIn("hello"), qsizetype(0));
+        QCOMPARE(m.indexIn("hellohello", qsizetype(2)), -1); // haystack is "he", not: from is 2
+        QCOMPARE(m.indexIn("hellohello", qsizetype(3)), 0); // haystack is "hel", not: from is 3
+        QCOMPARE(m.indexIn(hello), 0);
+        QCOMPARE(m.indexIn(hello2, qsizetype(2)), hello.size()); // from is 2
+        QCOMPARE(m.indexIn(hello2, qsizetype(3)), hello.size()); // from is 3
+    }
+}
+
 void tst_QByteArrayMatcher::interface()
 {
     const char needle[] = "abc123";