push/pop issue in p4v1.1 branch

[rhalstea]

Using a push or pop call is causing the retrieve_from_one_action function in the analysis_utils.py file to enter an unexpected state. The push/pop call has a p4_header_stack object as an argument that the function doesn't know how to handle.

Here's a P4 file (converted to .txt for github) that replicates the issue: sample.txt

[antoninbas]

Hi Robert,
Thanks for reporting this. I fixed it with 1fff5a0