Re: [java-gnome-hackers] gnome conflicts with gtkentry

[Tom B. <Tom...@Su...>]

With Sun's latest it crashes regularly for me in my app.  You should be
able to recreate this bug using src/examples/gtk/entry or
src/examples/gtk/text:  just type any character into a text or entry
field.  

I can't spend more time on this today (my real job gets in the way), but
the problem seems to be in org_gnu_glib_GObject.c:jg_signal_cb() with
uninitialized arguments being passed up to Java.  If one changes line
129 to read:

       jargs = alloca(n_param_values * sizeof(jvalue));
add => memset(jargs, 0, n_param_values * sizeof(jvalue));

then problems turn up more quickly due to null handles (0xCA is another
good memset choice since it's a rarely used but easily recognized memory
pattern).  The alloca call just allocates space on the stack, so it is
"initialized" to whatever garbage was on there previously.  

A related problem is that the first Java parameter was never initialized
due to the for loop reading "for(i = 1; i < n_param_values; i++)".  I
don't know if a starting index of one makes sense for a GClosureMarshall
function (there's no documentation), but it doesn't for the Java
argument array.  When I changed it to "i = 0;" things moved further, but
it fails in EventKey.getString with a bogus eventkey handle.

Would someone more familiar with the jg_signal_cb() code take a look at
this?

Tom

On Sun, 2003-04-06 at 16:00, Jeffrey Morgan wrote:
> That is very strange.  I can type as many characters
> as I wish into the gnome entry example and the gtk
> entry example and experience no problems.  Can you
> please try to run the examples with Sun's JDK?  It
> should produce an output file when it crashes named
> something like hs_err_pid9999.log.  If it doesn't 
> crash with Sun's JDK then the problem is when using
> it with the Blackdown JDK.  That will help me debug
> it.
> 
> On Sun, 2003-04-06 at 16:27, Mark Howard wrote:
> > On Sun, 2003-04-06 at 21:24, Mark Howard wrote:
> > > On Sun, 2003-04-06 at 20:37, Jeffrey Morgan wrote:
> > > > What happens on your system if you run the EntryTest example
> > > > under src/examples/gnome/entry?
> > > 
> > > Typing one character works.
> > > The example crashes when I type a second. 
> > > If I press backspace after the first character, it is deleted and I can
> > > type another character.
> > 
> > The same thing also happens when using a gtk entry.
-- 
Tom Ball <Tom...@Su...>