Return ObjectNode from ObjectNode set-methods in order to allow better chaining

[timo-schmid]

A minor improvement for the API: When returning ObjectNode instead of JsonNode one can chain after calling set and setAll (with no downside that's obvious for me).

Without this, it's necessary to cast the resulting JsonNode to ObjectNode (which always works).

Greetings!

[cowtowncoder]

Yes, from API perspective this would make sense.

Unfortunately it is also binary-compatibility breaking change that would literally break all existing code that calls these methods, because it changes method signature, and linker (code that loads in classes) would not find methods called by code that was compiled before the change.

Change can therefore not be made in Jackson 2.x at all (this change has been suggested multiple times). It may be made for 3.0, however. I will create separate issue for tracking this and related changes since there are other places as well.

[timo-schmid]

Aha, I see. Thanks for the quick response!

[cowtowncoder]

@timo-schmid Thank you contributing this -- I ended up changing this as part of 3.0 changes (forgot this patch would have separately done this), so this will be in 3.0.0.
Please let me know if there are other methods (I found one other in ArrayNode, but aside from that).