Hi,

After an entire day hunting the bug, i provide a tiny fix to save-buffer op that prevent it to eat all memory (due to default value in GeglCache).

In the future, i may implement the tile by tile memcpy instead of all in once as it is now. Attached the patch, with a ChangeLog entry ;). Basically, the fix is just a modification on how to get input buffer width, height, x and y. I just copyied the code from png-save which use gegl_operation_result_rect() instead of using fake input buffer values. I guess that the true fix would be to directly set input buffer width,height,x and y to gegl_operation_result_rect() upstream regarding to process().

This is my first patch to Gegl itself, not its build system :). I wish i'll be able to contribute more and more in the future but, as you can see, i prefer need public API in order to debug/improve Gegl because i'm primarily Gnome Scan developer and this is by using Gegl in Gnome Scan i will be able to find, hunt and fix bugs like this or add features like dynamic per instance properties for GeglOperation.

Kind regards, Étienne.