QTextStream: use write(QChar) more

Replace write(&ch, 1) calls with write(ch) ones.

The QChar overload, added in 31c6d9f04ba80e6776ae01cb0588e6bd228f7184,
is safer, because it has less preconditions. With QTextStream being
security-critical, we should target to use safer functions to do the
same work, even if it introduces a bit of git history churn.

The call from a different TU (qdebug.cpp) means we need to remove the
lying inline keywords from both declaration and definition of
write(QChar), because GCC -Werrors on them.

As a drive-by, remove a use of QLatin1Char, in preparation of moving
from QChar to char16_t, eventually.

Pick-to: 6.10 6.9 6.8
Change-Id: I97b4c8c68a4ee0d4b821c4d2ec4a9dd6f44dceb0
Reviewed-by: Thiago Macieira <[email protected]>

3 files changed, 7 insertions, 8 deletions

diff --git a/src/corelib/io/qdebug.cpp b/src/corelib/io/qdebug.cpp
index 70a688e40ff..5d6b5e06be6 100644
--- a/src/corelib/io/qdebug.cpp
+++ b/src/corelib/io/qdebug.cpp
@@ -200,7 +200,7 @@ template <typename Char>
 static inline void putEscapedString(QTextStreamPrivate *d, const Char *begin, size_t length, bool isUnicode = true)
 {
     QChar quote(u'"');
-    d->write(&quote, 1);
+    d->write(quote);
 
     bool lastWasHexEscape = false;
     const Char *end = begin + length;
@@ -227,8 +227,7 @@ static inline void putEscapedString(QTextStreamPrivate *d, const Char *begin, si
                 continue;
             }
         } else if (isPrintable(*p) && *p != '\\' && *p != '"') {
-            QChar c = QLatin1Char(*p);
-            d->write(&c, 1);
+            d->write(char16_t{uchar(*p)});
             continue;
         }
 
@@ -302,7 +301,7 @@ static inline void putEscapedString(QTextStreamPrivate *d, const Char *begin, si
         d->write(reinterpret_cast<QChar *>(buf), buflen);
     }
 
-    d->write(&quote, 1);
+    d->write(quote);
 }
 
 /*!
diff --git a/src/corelib/serialization/qtextstream.cpp b/src/corelib/serialization/qtextstream.cpp
index 5e0eff698f9..e4dc98af98b 100644
--- a/src/corelib/serialization/qtextstream.cpp
+++ b/src/corelib/serialization/qtextstream.cpp
@@ -711,7 +711,7 @@ void QTextStreamPrivate::write(const QChar *data, qsizetype len)
 /*!
     \internal
 */
-inline void QTextStreamPrivate::write(QChar ch)
+void QTextStreamPrivate::write(QChar ch)
 {
     if (string) {
         // ### What about seek()??
@@ -845,7 +845,7 @@ void QTextStreamPrivate::putString(const QChar *data, qsizetype len, bool number
             const QChar sign = len > 0 ? data[0] : QChar();
             if (sign == locale.negativeSign() || sign == locale.positiveSign()) {
                 // write the sign before the padding, then skip it later
-                write(&sign, 1);
+                write(sign);
                 ++data;
                 --len;
             }
@@ -874,7 +874,7 @@ void QTextStreamPrivate::putString(QLatin1StringView data, bool number)
             const QChar sign = data.size() > 0 ? QLatin1Char(*data.data()) : QChar();
             if (sign == locale.negativeSign() || sign == locale.positiveSign()) {
                 // write the sign before the padding, then skip it later
-                write(&sign, 1);
+                write(sign);
                 data = QLatin1StringView(data.data() + 1, data.size() - 1);
             }
         }
diff --git a/src/corelib/serialization/qtextstream_p.h b/src/corelib/serialization/qtextstream_p.h
index 7227c29c8fe..bf3ce7b2ef7 100644
--- a/src/corelib/serialization/qtextstream_p.h
+++ b/src/corelib/serialization/qtextstream_p.h
@@ -145,7 +145,7 @@ public:
     bool getReal(double *f);
 
     inline void write(QStringView data) { write(data.begin(), data.size()); }
-    inline void write(QChar ch);
+    void write(QChar ch);
     void write(const QChar *data, qsizetype len);
     void write(QLatin1StringView data);
     void writePadding(qsizetype len);