Re: [gtk-vnc-devel] [patch] versions

[Anthony Liguori <anthony codemonkey ws>]

Daniel P. Berrange wrote:
> On Sun, Jan 20, 2008 at 02:02:04PM -0300, Jonh Wendell wrote:
>   
> > Hi, gang!
> >
> > Due to vinagre get into GNOME 2.22 Desktop, I need to be more careful
> > when using gtk-vnc trunk.
> >
> > For example, I'm using the new function
> > vnc_display_set_lossy_encoding(), available only in trunk. This has
> > caused some issues on people trying to build vinagre from trunk.
> >
> > In order to fix this, I created a file vncversion.h.in, similar to
> > gtkversion.h.in, which we can test if we're compiling against a specific
> > version of gtk-vnc.
> >
> > In this case, I could just put in vinagre:
> > #if VNC_CHECK_VERSION(0, 3, 3)
> >   vnc_display_set_lossy_encoding (VNC_DISPLAY(tab->priv->vnc), TRUE);
> > #endif
> >
> > What do you think about this approach? OK to commit? comments?
> >     
>
> Doing checks based on version numbers is a really bad idea IMHO. The
> better approach is to check for the actual function in autoconf.
>   

I agree.  An autoconf check is definitely the right thing to do.

> eg in your configure.in add
>
>     old_LIBS="$LIBS"
>     LIBS="$LIBS $GTK_VNC_LDFLAGS"
>     AC_CHECK_FUNC(vnc_display_set_lossy_encoding)
>     LIBS="$old_LIBS"
>
> Then in your code you'll be able todo
>
>      #if HAVE_VNC_DISPLAY_SET_LOSSY_ENCODING
>       ....
>      #endif
>
> NB, make sure you include 'config.h' in all your files
>
>
> Alternatively  don't make use of new symbols from unreleased GTK-VNC
> code in the trunk for vinagre. Keep it on a branch off the trunk until
> the GTK-VNC release is done - since we release once a month this isn't
> too much hassle - and it saves cluttering up the vinagre code with lots
> of #if blocks.
>   

Yes, I agree.  Until a symbol appears in a release, we can't guarantee 
that it's signature will not change or that it won't disappear altogether.

Regards,

Anthony Liguori

> Regards,
> Dan.
>