... which is a drop-in replacement for gegl_buffer_copy(),
parallelizing the copy operation when the source and destination
formats are different, requiring a conversion.
In gimp_gegl_convert_color_profile(), when src/dest_rect is NULL,
use the extents of src/dest_buffer, instead of passing a NULL area
to gimp_parallel_distribute_area(), which results in a CRITICAL.
Additionally, only report progress on the main thread.
Commit cb239e60f6 introduced
artifacts when using the smudge tool with multithreads. Fix this
(caused by a wrong offset passed to an iterator) plus indentation
fixes.
