Context is cached improperly on nested schemas

I’m running into an issue where passing parameters down into a set of schemas is breaking. I essentially have this:

class RelationshipSchema(Schema):
    singular = fields.Nested(OtherSchema())
    plural = fields.Nested(OtherSchema(many=True))

I have attempted to set up plural with both a List(Nested(OtherSchema))) structure and the current Nested(OtherSchema(many=True)) structure. Both, initially, appear to work and parse. However, within a @post_load hook that needs to call self.context['request'].dbsession to get a database session, the plural fails: it will work on the first call after the services start, but then fail on subsequent calls as it somehow caches that self.context object.

My next workaround is going to be to use threadlocals.

[deckar01]

I am no longer able to reproduce this in the latest version of v2 and v3.

[lafrech]

I believe this was fixed by https://github.com/marshmallow-code/marshmallow/pull/960, merged in 3.0.0b16.

@deckar01 @asthasr Would you guys mind double-checking and closing if it is the case?