snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

tools/backport-pull-request

@@ -0,0 +1,103 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+    cat >&2 <<EOF
+usage: $0 PULL_REQUEST_ID
+
+Fetch the given GitHub pull request branch and backport it to
+the current branch using 'git cherry-pick -x'.
+
+Typical usage is:
+  git fetch upstream
+  git checkout -b 8.x upstream/8.x
+  $0 FIRST_PR_ID
+  $0 SECOND_PR_ID
+  git push origin +HEAD:backport-changes
+EOF
+    exit 1
+}
+
+pr_id="${1-}"
+
+if [ -z "$pr_id" ]; then
+    usage
+fi
+
+fail() {
+    echo "$1"
+    exit 1
+}
+
+type gh >/dev/null 2>&1 \
+    || fail "The 'gh' CLI tool is not installed; see https://cli.github.com/"
+gh auth status 2>/dev/null || fail "Not authenticated to github"
+
+# Find the last commit that was merged.  We will look back in `main`
+# for other commits from the same PR.
+# shellcheck disable=SC2016
+merge_commit="$(
+    gh api graphql \
+        -q '.data.repository.pullRequest.timelineItems.nodes[0].commit.oid' \
+        -F pr_id="$1" \
+        -f query='
+query($pr_id:Int!) {
+  repository(name: "zulip", owner: "zulip") {
+    pullRequest(number:$pr_id) {
+      timelineItems(last:1, itemTypes: [MERGED_EVENT]) {
+        nodes {
+          ... on MergedEvent {
+            commit {
+              oid
+            }
+          }
+        }
+      }
+    }
+  }
+}
+'
+)"
+
+[ -n "$merge_commit" ] || fail "PR #$pr_id is not merged into 'main'. Merge it first before backporting."
+
+# We cannot trust the "commits" count on the PR, since only part of it
+# may get merged, or it may have commits squashed during the merge.
+# Walk backwards on `main` from the merge commit we found, checking
+# that each of those commits is still associated with the same PR.
+commit_id="$merge_commit"
+while true; do
+    # shellcheck disable=SC2016
+    this_pr="$(gh api graphql -F "commit_id=$commit_id 0" \
+        --jq '.data.repository.ref.target.history.edges[].node.associatedPullRequests.nodes[].number' \
+        -f query='
+query($commit_id: String!) {
+  repository(owner: "zulip", name:"zulip") {
+    ref(qualifiedName:"main") {
+      target {
+        ... on Commit {
+          history(first:1, after: $commit_id) {
+            edges {
+              node {
+                oid
+                associatedPullRequests(first: 1) {
+                  nodes {
+                    number
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}')"
+    if [ "$this_pr" != "$pr_id" ]; then
+        break
+    fi
+    commit_id="$(git rev-parse "$commit_id"~)"
+done
+
+set -x
+git cherry-pick -x "$commit_id~..$merge_commit"