From 6f4da9a5d2b30b561bd96d62b90c8453e6ceb383 Mon Sep 17 00:00:00 2001
From: Michael Sproul <michael@sigmaprime.io>
Date: Tue, 9 Feb 2021 02:00:53 +0000
Subject: [PATCH] Check that pull requests target unstable (#2187)

Attempt to prevent accidental merges to `stable` due to GitHub's default behaviour of opening PRs against it.

I've intentionally opened this PR against `stable` to test the functionality ;)
---
 .github/workflows/test-suite.yml | 7 +++++++
 bors.toml                        | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/test-suite.yml b/.github/workflows/test-suite.yml
index 35dc8471a..04903d3c6 100644
--- a/.github/workflows/test-suite.yml
+++ b/.github/workflows/test-suite.yml
@@ -12,6 +12,13 @@ env:
   # Deny warnings in CI
   RUSTFLAGS: "-D warnings"
 jobs:
+  target-branch-check:
+    name: target-branch-check
+    runs-on: ubuntu-latest
+    if: github.event_name == 'pull_request'
+    steps:
+        - name: Check that pull request is targeting unstable branch
+          run: test ${{ github.base_ref }} = "unstable"
   cargo-fmt:
     name: cargo-fmt
     runs-on: ubuntu-latest
diff --git a/bors.toml b/bors.toml
index b7ce82b61..e12684e87 100644
--- a/bors.toml
+++ b/bors.toml
@@ -16,4 +16,4 @@ status = [
 ]
 use_squash_merge = true
 timeout_sec = 7200
-pr_status = ["license/cla"]
+pr_status = ["license/cla", "target-branch-check"]