[Gegl-developer] GEGL testbed

[Fredrik Alstromer]

Fredrik Alstromer wrote:
> Some of them end up in segfaults (which is ok, gives you a starting 
> point to work on, right?). I ended up examining the clones.c, which uses 
> an xml-parser to define the graph. It segfaults when in the call to 
> gegl_node_apply/gegl_eval_mgr_apply, as the gegl_node_get_pad returns null.
> 
> pad = gegl_node_get_pad (root, pad_name); /* returns NULL */
> 
> if (pad->node != root) /* segfault */
>     root = pad->node;
> 
> In an attempt to figure out how the stuff works, I traced through it a 
> couple of times, and it appears that the last statement in 
> gegl_xml_parse is part of the problem (the "hacky redirect" comment 
> being scary enough...) :)
> 
> /* hacky redirect */
> gegl_node_add_pad (ret, gegl_node_get_pad (pd->root, "output"));

This was indeed the problem, replacing the "output" with "process" 
solved the problem for all demos/tests based on xmls. However, it seems 
a bit far fetched that this would be just a typo, is there something 
else I missed which would correct the situation in a more reliable fashion?

> here the gegl_node_get_pad returns NULL as well. The pd->root seems to 
> correctly defined (the first <node> in the <tree>, I suppose?). Sure 
> enough this triggers an assertion failed, by the way, which I missed the 
> first couple of times around (I thought it was just another warning 
> related to the "unable to set operation threshold" problem). How do 
> these pads get defined? Any hints on what I missed? :)
> 
> Thanks,
> 

/ Fredrik.