--output function isn't working

[Louis Popi <theh2o64 gmail com>]

Hi !
I recently posted a bug report about git + meld on Ubuntu 15.04. I 
investigated more and I discovered that, in fact, the --output have some 
graphic gliches.
So, I'll do a quick explaination :
- I have two different files orig and remote
When I do a simple 'meld orig remote' it directly lauches meld and shows 
me a classical differencial (like this http://hpics.li/dc89e46)
However when I create an empty file called "merge" and I do 'meld orig 
remote --output merge', I have first this error message on the console :
"/usr/bin/meld:274: Warning: g_object_unref: assertion 'G_IS_OBJECT 
(object)' failed
  status = meld.meldapp.app.run(sys.argv)"
and my screen is like that http://hpics.li/516ca18
and when I (on the right side of the window) click on "Browse" and 
select the "merge" file again here is what I got http://hpics.li/9995e69

So, this bug is happening using git : I lauchned 'git mergetool' wich 
basically runs the 'meld --output' command. I got the same error message 
and to make the diff flags (>>>>) appears I have to manually reopen the 
middle file, the "merge" file.

This bug is really annoying, and may causes issues to a lot of 
developpers as me who merged wrong stuff.

Thanks for reading me and I hope you will find out a solution.