From b2c55f73f5bd9700def602e47538844e4d742914 Mon Sep 17 00:00:00 2001
From: Nick Telford <nick.telford@gmail.com>
Date: Thu, 19 Oct 2023 14:59:38 +0100
Subject: [PATCH] MINOR: Fix Gradle when git refs are packed

When `git gc` runs, which can run automatically on large repos like
Kafka, it packs all refs under `.git/refs/heads` into a single
`.git/packed-refs` file.

When this happens, the Gradle build can no longer locate the ref in
`.git/refs/heads` that it expects.

We fix this by having Gradle also search for the `.git/packed-refs`
file if it cannot find the ref in `.git/refs/heads`.
---
 build.gradle | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/build.gradle b/build.gradle
index 8fc01156a86d6..70b4afea293da 100644
--- a/build.gradle
+++ b/build.gradle
@@ -170,6 +170,12 @@ def determineCommitId() {
       headRef = headRef.replaceAll('ref: ', '').trim()
       if (file("$rootDir/.git/$headRef").exists()) {
         file("$rootDir/.git/$headRef").text.trim().take(takeFromHash)
+      } else if (file("$rootDir/.git/packed-refs").exists()) {
+        file("$rootDir/.git/packed-refs").text.lines()
+          .filter { it.endsWith(headRef) }
+          .map { it.replaceAll(headRef, '').trim().take(takeFromHash) }
+          .findFirst()
+          .orElseGet { "unknown" }
       }
     } else {
       headRef.trim().take(takeFromHash)