Thomas Braxton brax108 at cox.net
Sun Feb 12 21:17:42 GMT 2006

On Sunday 12 February 2006 14:01, Michael Pyne wrote:
> This is true even if we're not switching to DBUS, since the on-wire
> interface to QByteArray of some types changed in Qt 4.  An application
> would have to manually ask for the old interface to ensure compatibility.
>  This isn't as difficult a problem as we could fix it by altering dcopidl
> for the 99% of applications that use a DCOP IDL.  But I'd hate to be the
> one trying to test that setup. :-/
Actually this isn't entirely true, QDataStream reads the version from the 
stream, so KDE4 apps will be able to read calls from KDE3 apps. The problem 
is with KDE4 -> KDE3, we have to explicitly set the version on the stream to 
an earlier version if we're talking to a KDE3 app before we write to that 
stream so that the KDE3 app would get the version of the stream that it 
Even right now there may be subtle problems with some KDE3 apps talking to 
each other because TT changed the format of QDataStream, so if you have an 
app compiled with Qt3.2 and one compiled with Qt3.3 they might have some 
subtle incompatibilities in the stream. I'm not sure what changed between 
Qt3.2 & Qt3.3 but TT changed the version number on QDataStream so I assume 
there are differences between the two.

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