From 89a7356933e8baba0fe2e470d04790aaf13e63a8 Mon Sep 17 00:00:00 2001
From: Melvin Carvalho <melvincarvalho@gmail.com>
Date: Sat, 16 May 2026 20:45:17 +0200
Subject: [PATCH] fix(git): pin auto-init default branch to `main` for
 predictable updateInstead

`git init` (no `-b`) honours the server's `init.defaultBranch`, which
on a server configured for e.g. `gh-pages` makes pushes to `main`
silently fail to extract the working tree (the ref updates but
`receive.denyCurrentBranch updateInstead` only fires when the push
matches the branch HEAD points at).

Pass `-b main` explicitly so the auto-init'd HEAD is deterministic
regardless of server config. `git push pod HEAD:main` then works on
every deployment.

Adds a test reading `.git/HEAD` and asserting `ref: refs/heads/main`.

Fixes #471
---
 src/handlers/git.js        |  8 +++++++-
 test/git-auto-init.test.js | 17 ++++++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/handlers/git.js b/src/handlers/git.js
index 2eced00c..3573bcae 100644
--- a/src/handlers/git.js
+++ b/src/handlers/git.js
@@ -140,7 +140,13 @@ function tryAutoInitRepo(repoAbs, log) {
     } else {
       mkdirSync(repoAbs, { recursive: true });
     }
-    const result = spawnSync('git', ['init', repoAbs], {
+    // Pin the initial branch to `main` regardless of the server's
+    // `init.defaultBranch` config. `receive.denyCurrentBranch
+    // updateInstead` only extracts the working tree when the push
+    // targets the branch HEAD points at, so a deterministic default
+    // keeps `git push pod HEAD:main` working on every deployment. See
+    // #471.
+    const result = spawnSync('git', ['init', '-b', 'main', repoAbs], {
       stdio: ['ignore', 'pipe', 'pipe']
     });
     if (result.status !== 0) {
diff --git a/test/git-auto-init.test.js b/test/git-auto-init.test.js
index f55bdfb8..db651d91 100644
--- a/test/git-auto-init.test.js
+++ b/test/git-auto-init.test.js
@@ -15,7 +15,7 @@ import { createServer } from '../src/server.js';
 import { createServer as createNetServer } from 'net';
 import fs from 'fs-extra';
 import path from 'path';
-import { existsSync, statSync, writeFileSync } from 'fs';
+import { existsSync, statSync, writeFileSync, readFileSync } from 'fs';
 
 const TEST_HOST = 'localhost';
 const DATA_DIR = './test-data-git-auto-init';
@@ -77,6 +77,21 @@ describe('Git auto-init on first push', () => {
     assert.ok(existsSync(path.join(dotGit, 'refs')), '.git/refs must exist');
   });
 
+  it('pins the initial branch to `main` regardless of server config', async () => {
+    // `updateInstead` only extracts the working tree when the push
+    // targets the branch HEAD points at. If `git init` honoured the
+    // server's `init.defaultBranch`, a server configured for e.g.
+    // `gh-pages` would silently fail to extract files pushed to `main`.
+    // Pin the auto-init'd HEAD so `git push pod HEAD:main` works
+    // everywhere. See #471.
+    const repoPath = 'public/apps/penny';
+    const headPath = path.resolve(DATA_DIR, repoPath, '.git', 'HEAD');
+    assert.ok(existsSync(headPath), 'prereq: repo from earlier test still exists');
+    const head = readFileSync(headPath, 'utf8').trim();
+    assert.strictEqual(head, 'ref: refs/heads/main',
+      `HEAD must point at refs/heads/main, got: ${head}`);
+  });
+
   it('auto-inits a regular repo when the target directory exists but is empty', async () => {
     const repoPath = 'public/empty-dir';
     await fs.ensureDir(path.resolve(DATA_DIR, repoPath));