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

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

src/tools/qstring.cpp

@@ -5768,6 +5768,10 @@ QCString QString::utf8() const
  	++ch;
     }
     rstr.truncate( cursor - (uchar*)rstr.data() );
+    if (!d->cString) {
+        d->cString = new QCString;
+    }
+    *d->cString = rstr;
     return rstr;
 }
 
@@ -5964,23 +5968,28 @@ 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

@@ -360,11 +360,13 @@ inline bool operator>( QChar c1, QChar c2 ) { return !(c2>=c1); }
 // internal
 struct Q_EXPORT QStringData : public QShared {
     QStringData() :
-        QShared(), unicode(0), ascii(0), len(0), issimpletext(TRUE), maxl(0), islatin1(FALSE) { ref(); }
+        QShared(), unicode(0), ascii(0), len(0), issimpletext(TRUE), maxl(0), islatin1(FALSE), cString(0) { ref(); }
     QStringData(QChar *u, uint l, uint m) :
-        QShared(), unicode(u), ascii(0), len(l), issimpletext(FALSE), maxl(m), islatin1(FALSE) { }
+        QShared(), unicode(u), ascii(0), len(l), issimpletext(FALSE), maxl(m), islatin1(FALSE), cString(0) { }
     ~QStringData() { if ( unicode ) delete[] ((char*)unicode);
-                     if ( ascii ) delete[] ascii; }
+                     if ( ascii ) delete[] ascii;
+                     if (cString) delete cString;
+                   }
 
     void deleteSelf();
     QChar *unicode;
@@ -374,6 +376,10 @@ struct Q_EXPORT QStringData : public QShared {
 	    delete [] ascii;
 	    ascii = 0;
 	}
+	if (cString) {
+	    delete cString;
+	    cString = 0;
+	}
 	issimpletext = FALSE;
     }
 #ifdef Q_OS_MAC9
@@ -389,6 +395,8 @@ struct Q_EXPORT QStringData : public QShared {
 #endif
     uint islatin1 : 1;
 
+    QCString *cString;
+
 private:
 #if defined(Q_DISABLE_COPY)
     QStringData( const QStringData& );