grep: fix logic for empty patterns #529

	# This action requires a personal access token with issues and pull requests
	# read-write permissions. The GITHUB_TOKEN that the action supplies only
	# has read permissions since the merge is coming from a fork (usually).
	name: merge-labeler

	# https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request
	on:
	pull_request:
	types:
	- closed

	jobs:
	relabel:
	if: github.event.pull_request.merged == true
	runs-on: ubuntu-latest
	environment: merge
	steps:
	- uses: actions/checkout@v3
	- env:
	MERGE_TOKEN: ${{ env.MERGE_TOKEN }}
	run: \|
	echo MERGE_TOKEN $MERGE_TOKEN \| hexdump -C
	perl util/merge-labeler ${{ github.repository }} ${{ github.event.number }}

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