...with filters during Recompose
Previously, get_buffer_with_filters() inserted and removed a temporary
copy of a layer in the original image. This caused the image to appear
modified, adding entries in the undo history and prompting the user to save
changes, even though the image itself was not actually changed.
This patch modifies the function to create a temporary image and perform
the layer insert operation there. Filters are applied as before,
but the original image remains untouched, avoiding unwanted undo entries
and mark the image as modified.
6e80f98390