DCtx::try clone (experimental feature, deprecated) is a plain copy of the C context. A context owning a dictionary (from load dictionary, ref prefix or init using dict) or a dictionary table (ref ddict with RefMultipleDDicts) ended up with both copies freeing it. A context cloned mid-frame resumed on uninitialized stream state. The clone also silently lost the WindowLogMax limit.

The flaw was corrected by refusing to clone such contexts, and by carrying over the parameters the copy leaves out.