From 18e95af24f762cc1ad0ec23f619721422fe8e68a Mon Sep 17 00:00:00 2001
From: Jason Song <i@wolfogre.com>
Date: Wed, 20 Mar 2024 09:45:27 +0800
Subject: [PATCH] Restore deleted branches when syncing (#29898)

Regression of #29493. If a branch has been deleted, repushing it won't
restore it.

Lunny may have noticed that, but I didn't delve into the comment then
overlooked it:
https://github.com/go-gitea/gitea/pull/29493#discussion_r1509046867

The additional comments added are to explain the issue I found during
testing, which are unrelated to the fixes.

(cherry picked from commit f371f84fa3456c2a71470632b6458d81e4892a54)
---
 routers/private/hook_post_receive.go |  4 ++++
 tests/integration/git_push_test.go   | 17 +++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/routers/private/hook_post_receive.go b/routers/private/hook_post_receive.go
index f5527cb15b..fff47caa88 100644
--- a/routers/private/hook_post_receive.go
+++ b/routers/private/hook_post_receive.go
@@ -75,6 +75,10 @@ func HookPostReceive(ctx *gitea_context.PrivateContext) {
 			updates = append(updates, option)
 			if repo.IsEmpty && (refFullName.BranchName() == "master" || refFullName.BranchName() == "main") {
 				// put the master/main branch first
+				// FIXME: It doesn't always work, since the master/main branch may not be the first batch of updates.
+				//        If the user pushes many branches at once, the Git hook will call the internal API in batches, rather than all at once.
+				//        See https://github.com/go-gitea/gitea/blob/cb52b17f92e2d2293f7c003649743464492bca48/cmd/hook.go#L27
+				//        If the user executes `git push origin --all` and pushes more than 30 branches, the master/main may not be the default branch.
 				copy(updates[1:], updates)
 				updates[0] = option
 			}
diff --git a/tests/integration/git_push_test.go b/tests/integration/git_push_test.go
index cb2910b175..0a35724807 100644
--- a/tests/integration/git_push_test.go
+++ b/tests/integration/git_push_test.go
@@ -69,6 +69,23 @@ func testGitPush(t *testing.T, u *url.URL) {
 			return pushed, deleted
 		})
 	})
+
+	t.Run("Push to deleted branch", func(t *testing.T) {
+		runTestGitPush(t, u, func(t *testing.T, gitPath string) (pushed, deleted []string) {
+			doGitPushTestRepository(gitPath, "origin", "master")(t) // make sure master is the default branch instead of a branch we are going to delete
+			pushed = append(pushed, "master")
+
+			doGitCreateBranch(gitPath, "branch-1")(t)
+			doGitPushTestRepository(gitPath, "origin", "branch-1")(t)
+			pushed = append(pushed, "branch-1")
+
+			// delete and restore
+			doGitPushTestRepository(gitPath, "origin", "--delete", "branch-1")(t)
+			doGitPushTestRepository(gitPath, "origin", "branch-1")(t)
+
+			return pushed, deleted
+		})
+	})
 }
 
 func runTestGitPush(t *testing.T, u *url.URL, gitOperation func(t *testing.T, gitPath string) (pushed, deleted []string)) {