From 3cd05f053062efd8b50d294df8aedef0f5eadbf7 Mon Sep 17 00:00:00 2001
From: Jonatan Ivanov <jonatan.ivanov@gmail.com>
Date: Mon, 30 Oct 2023 16:21:54 -0700
Subject: [PATCH] Check if a tag or branch is checked out by Antora

---
 build.gradle | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/build.gradle b/build.gradle
index 70243992bb..4c9f54127f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -38,10 +38,13 @@ buildscript {
 // TODO: remove these hacks once jgit supports worktrees (nebula upgrades) and/or Antora supports full-clone
 if (project.hasProperty('antora')) {
     'git fetch --unshallow --all --tags'.execute().text // Antora shallow-clones so there is no history (we need commit history to find the last tag in the tree)
-    String tag = 'git tag --points-at HEAD'.execute().text.trim() // jgit does not able to figure out tags in Antora's worktree
-    if (tag) {
-        println "Found release tag: $tag, using it as release.version"
-        ext['release.version'] = tag.substring(1)
+    String ref = 'git rev-parse --abbrev-ref HEAD'.execute().text.trim()
+    if (ref == 'HEAD') { // if Antora checks out a tag instead of a branch
+        String tag = 'git tag --points-at HEAD'.execute().text.trim() // jgit does not able to figure out tags in Antora's worktree
+        if (tag) {
+            println "Found release tag: $tag, using it as release.version"
+            ext['release.version'] = tag.substring(1)
+        }
     }
     // We need to tell the location of the .git folder since jgit does not support worktrees
     ext['git.root'] = 'git rev-parse --path-format=absolute --git-common-dir'.execute().text.trim()