memory leak - cairo/x11 backend

[Riccardo Mottola]

Hi,

testing stuff before "release" as Fred asked gets me to this (I think 
this problem has been around since a while, it just happened that 
yesterday I stressed everything with very big files). A couple of weeks 
ago I had my image viewer crash under OpenBSD on an older Laptop, but I 
didn't consider that back then.

1) Use current LaternaMagica
2) load very big images (e.g.30/40 MPixels) and view them back and forth
3) check memory

What you will notice is that while LaternaMagica stays about constant in 
memory requirements, the memory allocated to Xorg grows and grows (I got 
it here in the 1-2G range, on older system it crashes).

I suppose we cache our images in the X server and do not release them 
well, in this case they are very big and it becomes apparent.
If LM is closed regulary, most of the Xorg RAM will be freed again.

I don't know where the fault is, but I suppose it shouldn't be in 
LaternaMagica itself, since I the application ram doesn't increase much.
I tried to do the same on my Mac and everything works fine, further 
supporting that it is not LM itself.

I will try with xlib and art backends.

Riccardo