Colin Walters authored Jul 05, 2014 and Matthias Clasen committed Jul 18, 2014

GdkPixbuf is an old API that predates introspection and GBytes.  It
has some confusion around whether or not pixbuf data is mutable or
not.  The _new_from_data() API takes a *const* pointer, but it's not
copied, and _get_pixels() returns a non-const copy of the same
pointer.

There are several cases where we get read-only data, such as a
GResource.  For language bindings, _new_from_data() doesn't work
because the array may be a temporary copy only allocated for the call.

In order to support a clean _new_from_bytes() API, we need to add the
concept of a read-only pixbuf into the core.  The fundamental hack
here is that _get_pixels() now causes an implicit copy.

For the cases where we don't want to copy, add a new
gdk_pixbuf_read_pixels() that returns a proper const pointer.

https://bugzilla.gnome.org/show_bug.cgi?id=732297