Add PR backport script.

1 files changed, 60 insertions, 0 deletions

diff --git a/dev/tools/backport-pr.sh b/dev/tools/backport-pr.sh
new file mode 100755
index 000000000..bc6ee3191
--- /dev/null
+++ b/dev/tools/backport-pr.sh
@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+
+# Usage: git-backport <PR number>
+
+set -e
+
+PRNUM=$1
+
+if ! git log master --grep "Merge PR #${PRNUM}" | grep "." > /dev/null; then
+    echo "PR #${PRNUM} does not exist."
+    exit 1
+fi
+
+SIGNATURE_STATUS=$(git log master --grep "Merge PR #${PRNUM}" --format="%G?")
+git log master --grep "Merge PR #${PRNUM}" --format="%GG"
+if [[ "${SIGNATURE_STATUS}" != "G" ]]; then
+    echo
+    read -p "Merge commit does not have a good (valid) signature. Bypass? [y/N] " -n 1 -r
+    echo
+    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
+        exit 1
+    fi
+fi
+
+BRANCH=backport-pr-${PRNUM}
+RANGE=$(git log master --grep "Merge PR #${PRNUM}" --format="%P" | sed 's/ /../')
+MESSAGE=$(git log master --grep "Merge PR #${PRNUM}" --format="%s" | sed 's/Merge/Backport/')
+
+if git checkout -b ${BRANCH}; then
+
+    if ! git cherry-pick -x ${RANGE}; then
+        echo "Please fix the conflicts, then exit."
+        bash
+        while ! git cherry-pick --continue; do
+            echo "Please fix the conflicts, then exit."
+            bash
+        done
+    fi
+    git checkout -
+
+else
+
+    echo
+    read -p "Skip directly to merging phase? [y/N] " -n 1 -r
+    echo
+    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
+        exit 1
+    fi
+
+fi
+
+git merge -S --no-ff ${BRANCH} -m "${MESSAGE}"
+git branch -d ${BRANCH}
+
+# To-Do:
+# - Support for backporting a PR before it is merged
+# - Automatically backport all PRs in the "Waiting to be backported" column using a command like:
+# $ curl -s -H "Authorization: token ${GITHUB_TOKEN}" -H "Accept: application/vnd.github.inertia-preview+json" https://api.github.com/projects/columns/1358120/cards | jq -r '.[].content_url' | grep issue | sed 's/^.*issues\/\([0-9]*\)$/\1/' | tac
+# (The ID of the column must first be obtained through https://api.github.com/repos/coq/coq/projects then https://api.github.com/projects/819866/columns.)
+# - Then move each of the backported PR to the subsequent columns automatically as well...