From 9f2564735b972a2d7d717346a42081dd255b74f9 Mon Sep 17 00:00:00 2001
From: KPal <kpal81xd@gmail.com>
Date: Thu, 22 Oct 2026 18:46:28 +0100
Subject: [PATCH] fix: skip backports the release branch already has

A fix backported by hand under a different patch cherry-picks as an empty commit, which failed the release as a conflict. Empty picks are now dropped and logged as already on the branch.
---
 scripts/release.ts           | 9 ++++++---
 test/release/release.test.ts | 9 +++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/scripts/release.ts b/scripts/release.ts
index bc6c876a4..b6f45419a 100644
--- a/scripts/release.ts
+++ b/scripts/release.ts
@@ -126,14 +126,17 @@ export const release = (cwd: string, { type, bumpEngine }: Options, deps: Deps)
                 continue;
             }
             git('checkout', '-q', '--detach', head);
-            if (!ok('cherry-pick', '-x', sha)) {
+
+            // a fix backported by hand under a different patch applies as nothing, so it's dropped
+            if (!ok('cherry-pick', '-x', '--empty=drop', sha)) {
                 git('cherry-pick', '--abort');
                 throw new Error(
                     `Backport of #${number} conflicts on ${branch}; backport it by hand or remove its "${BACKPORT_LABEL}" label`
                 );
             }
-            head = git('rev-parse', 'HEAD');
-            console.log(`Backported #${number}`);
+            const picked = git('rev-parse', 'HEAD');
+            console.log(picked === head ? `Skipping #${number}: already on ${branch}` : `Backported #${number}`);
+            head = picked;
         }
         head = withEngine(head);
         if (!git('rev-list', '-1', `${latest}..${head}`)) {
diff --git a/test/release/release.test.ts b/test/release/release.test.ts
index b0c99b248..e284824b6 100644
--- a/test/release/release.test.ts
+++ b/test/release/release.test.ts
@@ -91,6 +91,15 @@ describe('release', function () {
         expect(refs()).to.equal(before);
     });
 
+    it('skips a backport the branch already has under a different patch', () => {
+        run('minor');
+        picks = [{ number: 9, title: 'fix: b', sha: land('main', 'b.txt', 'b') }];
+        land('release-2.34', 'b.txt', 'old');
+        land('release-2.34', 'b.txt', 'b');
+        expect(run('patch')).to.deep.equal({ tag: 'v2.34.1', released: true });
+        expect(sh(remote, 'show', 'release-2.34:b.txt')).to.equal('b');
+    });
+
     it('does nothing when there is nothing to release', () => {
         run('minor');
         const before = refs();