[PATCH 1/1] msgpack: validate msgpack.decode() cdata size argument

[Vladimir Davydov]

On Fri, May 17, 2019 at 02:44:25PM +0300, Vladislav Shpilevoy wrote:
> Negative size led to an assertion. The commit adds a check if
> size is negative.
> 
> Closes #4224

Pushed to master, 2.1, and 1.10.