/return executed within an advancement reward function globally discards all subsequent commands

The bug

When /return is executed within an advancement reward function, it will discard all subsequent commands globally, not just the local commands that the function has.

How to reproduce

1. Install the data pack in Attachments

2. Run

   /function mc-266968:a

Results

The following table shows whether each message was expected to be printed or not, and whether it was actually printed or not.

As the table suggests, say a-2 in mc-266968:a was not executed because it was discarded by return 0 in mc-266968:b.

Resources

data/mc-266968/functions/a.mcfunction

say a-1
advancement grant @s only mc-266968:b
say a-2

data/mc-266968/functions/b.mcfunction

advancement revoke @s only mc-266968:b
say b-1
return 0
say b-2

data/mc-266968/advancements/b.json

{
  "criteria": {
    "": {
      "trigger": "impossible"
    }
  },
  "rewards": {
    "function": "mc-266968:b"
  }
}

Code analysis

An advancement reward function is executed as an initial function, which has a frame with depth 0, regardless of the current depth. Because /return discards all command queue entries above the depth of the currently executed function, /return executed in an advancement reward function discards all entries, which have a depth >= 0.