Make use of QString::utf8() and QString::local8Bit() safe for conversion to char*.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 0a1966b25e)

src/tools/qstring.cpp

@@ -1051,7 +1051,8 @@ QStringData::QStringData() : QShared(),
 	issimpletext(TRUE),
 	maxl(0),
 	islatin1(FALSE),
-	security_unpaged(FALSE) {
+	security_unpaged(FALSE),
+	cString(0) {
 #if defined(QT_THREAD_SUPPORT) && defined(MAKE_QSTRING_THREAD_SAFE)
 	mutex = new QMutex(FALSE);
 #endif // QT_THREAD_SUPPORT && MAKE_QSTRING_THREAD_SAFE
@@ -1065,7 +1066,8 @@ QStringData::QStringData(QChar *u, uint l, uint m) : QShared(),
 	issimpletext(FALSE),
 	maxl(m),
 	islatin1(FALSE),
-	security_unpaged(FALSE) {
+	security_unpaged(FALSE),
+	cString(0) {
 #if defined(QT_THREAD_SUPPORT) && defined(MAKE_QSTRING_THREAD_SAFE)
 	mutex = new QMutex(FALSE);
 #endif // QT_THREAD_SUPPORT && MAKE_QSTRING_THREAD_SAFE
@@ -1083,6 +1085,9 @@ QStringData::~QStringData() {
 	if ( ascii ) {
 		delete[] ascii;
 	}
+	if (cString) {
+		delete cString;
+	}
 #if defined(QT_THREAD_SUPPORT) && defined(MAKE_QSTRING_THREAD_SAFE)
 	if ( mutex ) {
 		delete mutex;
@@ -1096,6 +1101,10 @@ void QStringData::setDirty() {
 		delete [] ascii;
 		ascii = 0;
 	}
+	if (cString) {
+		delete cString;
+		cString = 0;
+	}
 	issimpletext = FALSE;
 }
 
@@ -6026,6 +6035,10 @@ QCString QString::utf8() const
  	++ch;
     }
     rstr.truncate( cursor - (uchar*)rstr.data() );
+    if (!d->cString) {
+        d->cString = new QCString;
+    }
+    *d->cString = rstr;
     return rstr;
 }
 
@@ -6227,23 +6240,28 @@ QString QString::fromLatin1( const char* chars, int len )
 
 QCString QString::local8Bit() const
 {
+    if (!d->cString) {
+        d->cString = new QCString;
+    }
 #ifdef QT_NO_TEXTCODEC
-    return latin1();
+    *d->cString = QCString(latin1());
+    return *d->cString;
 #else
 #ifdef Q_WS_X11
     QTextCodec* codec = QTextCodec::codecForLocale();
-    return codec
-	    ? codec->fromUnicode(*this)
-	    : QCString(latin1());
+    *d->cString = codec ? codec->fromUnicode(*this) : QCString(latin1());
+    return *d->cString;
 #endif
 #if defined( Q_WS_MACX )
     return utf8();
 #endif
 #if defined( Q_WS_MAC9 )
-    return QCString(latin1()); //I'm evil..
+    *d->cString = QCString(latin1()); //I'm evil..
+    return *d->cString;
 #endif
 #ifdef Q_WS_WIN
-    return isNull() ? QCString("") : qt_winQString2MB( *this );
+    *d->cString = isNull() ? QCString("") : qt_winQString2MB( *this );
+    return *d->cString;
 #endif
 #ifdef Q_WS_QWS
     return utf8(); // ### if there is any 8 bit format supported?

src/tools/qstring.h

@@ -384,6 +384,7 @@ struct Q_EXPORT QStringData : public QShared {
     bool security_unpaged : 1;
 
     QMutex* mutex;
+    QCString *cString;
 
 private:
 #if defined(Q_DISABLE_COPY)