1 files changed, 61 insertions, 2 deletions
diff --git a/build.gradle b/build.gradle
index a1aa9e9..cb11dcb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,14 +1,22 @@
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'org.eclipse.jgit:org.eclipse.jgit:5.10.0.202012080955-r'
+    }
+}
+
 plugins {
   id 'java-library'
   id 'maven-publish'
   id 'eclipse'
   id 'net.minecrell.licenser' version '0.3'
-  id 'org.ajoberstar.grgit' version '4.1.0'
 }
 
 group = 'net.minecraftforge'
 
-version = (grgit.describe(longDescr: true, tags: true) ?: 'unknown-unknown-unknown').split('-').with { "${it[0]}.${it[1]}" }
+version = gitVersion()
 println('Version: ' + version + ' Java: ' + System.getProperty('java.version') + ' JVM: ' + System.getProperty('java.vm.version') + '(' + System.getProperty('java.vendor') + ') Arch: ' + System.getProperty('os.arch'))
 
 sourceSets {
@@ -160,3 +168,54 @@ publishing {
     }
 }
 
+def gitInfo(dir) {
+    String.metaClass.rsplit = { String del, int limit = -1 ->
+        def lst = new ArrayList()
+        def x = 0, idx
+        def tmp = delegate
+        while ((idx = tmp.lastIndexOf(del)) != -1 && (limit == -1 || x++ < limit)) {
+            lst.add(0, tmp.substring(idx + del.length(), tmp.length()))
+            tmp = tmp.substring(0, idx)
+        }
+        lst.add(0, tmp)
+        return lst
+    }
+    
+    def git = null
+    try {
+        git = org.eclipse.jgit.api.Git.open(dir)
+    } catch (org.eclipse.jgit.errors.RepositoryNotFoundException e) {
+        return [
+            tag: '0.0',
+            offset: '0',
+            hash: '00000000',
+            branch: 'master',
+            commit: '0000000000000000000000',
+            abbreviatedId: '00000000'
+        ]
+    }
+    def desc = git.describe().setLong(true).setTags(true).call().rsplit('-', 2)
+    def head = git.repository.exactRef('HEAD')
+    def longBranch = head.symbolic ? head?.target?.name : null // matches Repository.getFullBranch() but returning null when on a detached HEAD
+
+    def ret = [:]
+    ret.tag = desc[0]
+    ret.offset = desc[1]
+    ret.hash = desc[2]
+    ret.branch = longBranch != null ? org.eclipse.jgit.lib.Repository.shortenRefName(longBranch) : null
+    ret.commit = org.eclipse.jgit.lib.ObjectId.toString(head.objectId)
+    ret.abbreviatedId = head.objectId.abbreviate(8).name()
+    
+    return ret
+}
+
+def gitVersion() {
+    def info = gitInfo(rootProject.file('.'))
+    def branch = info.branch
+    if (branch != null && branch.startsWith('pulls/'))
+        branch = 'pr' + branch.rsplit('/', 1)[1]
+    if (branch in [null, 'master', 'HEAD'])
+        return "${info.tag}.${info.offset}".toString()
+    return "${info.tag}.${info.offset}-${branch}".toString()
+}
+