incorrect (?) parsing of extra key=value parameters at end of alias chatops commands

SUMMARY

when providing a string parameter to an alias command (such as - blah {{string_value}} ),
when that input string contains an "=" character - the string value is cut incorrectly assuming the "=" to denote a key:value extra parameter - overriding the required parameter.

STACKSTORM VERSION

st2 3.2.0, on Python 2.7.5

OS, environment, install method

centOS 7 - installation on a single host as described at https://docs.stackstorm.com/install/rhel7.html

Steps to reproduce the problem

have a simple alias:

---
name: "test alias"
action_ref: "core.noop"
description: "test for data structs"
formats:
  - bar {{ someval }}
ack:
  enabled: false
result:
  format: |
      a parameter: {{execution.parameters.someval}}

Bug condition: invoke this alias via chat client with the command:
!bar https://www.foo.com/api/v1?some=url&with=eqchars

Expected Results

Chatbot should return
a parameter: https://www.foo.com/api/v1?some=url&with=eqchars

Actual Results

Chatbot returns:
Command "bar https://www.foo.com/?some=url&with=eqchars" doesn't match format string "bar {{ someval }}"

Extra Info

complex strings with spaces and special characters are handled just fine - except when containing an '='

this issue seems to come from st2/st2common/st2common/models/utils/action_alias_utils.py where extra parameters are parsed before anything else and then cut from the command relying on the condition that it contains a '=' without checking if all other required parameters have been parsed first, effectively cutting the last string parameter from the command and parsing it as extra key:value pair instead of what it's supposed to be.

so my theory - in the example failure - the resulting parameters parsed from the alias command will be :

{"parameters": {
  "https://www.foo.com/?some": "url&with=eqchars" }
}

instead of:

{"parameters": {
  "someval": "https://www.foo.com/?some=url&with=eqchars" }
}

Hope that helps...

Thanks!

Start with st2/st2common/st2common/models/utils/action_alias_utils.py and reproduce the alias command using the URL containing embedded '=' characters. Trace how extra parameters are parsed relative to required parameters; done means the alias preserves the complete URL as someval and returns the expected result.