Describe the bug
The walk function says it, "applies f recursively to every component of the input entity." However, it does not seem to apply to an inner object, after a match has been made. i.e. a child object will not be matched if its parent matches.

To Reproduce
In my example, I am pulling data from a child object, into the parent object. This works just fine for the 'a.MATCH.c' case below, but fails for 'a.inner.MATCH.b'. Possibly a documentation issue (in that case, how do I recursively match?), a bug or is my code pulling into an object that gets removed?

CODE:

jq '. * walk( if type == "object" and has("MATCH") then .|=.MATCH else . end) ' a.json

INPUT:

{
  "a" : {
    "inner" : {
      "MATCH" : {
        "b" : 1
      } 
    },
    "MATCH" : {
      "c" : 2
    } 
  }
}

OUTPUT:

The a.MATCH.c is brought out to a.c but a.inner.MATCH.b is not brought out into a.inner.b.

{
  "a": {
    "inner": {
      "MATCH": {
        "b": 1
      }
    },
    "MATCH": {
      "c": 2
    },
    "c": 2
  }
}

Expected behavior

EXPECTED:
I would expect a.inner.b to exist.

{
  "a" : {
    "inner" : {
      "MATCH" : {
        "b" : 1
      },
      "b" : 1
    },
    "MATCH" : {
      "c" : 2
    },
    "c" : 2
  }
}

Environment (please complete the following information):

• macOS - 10.13.6
• jq version - jq-HEAD-8eff744

Additional context
Add any other context about the problem here.