Allow single-commit to work cross repo (#979)

* Adjustments

* Formatting

__tests__/main.test.ts

@@ -2,6 +2,7 @@
 process.env['INPUT_FOLDER'] = 'build'
 process.env['GITHUB_SHA'] = '123'
 process.env['INPUT_DEBUG'] = 'debug'
+process.env['GITHUB_REF_NAME'] = 'test'
 
 import '../src/main'
 import {action, TestFlag} from '../src/constants'

src/lib.ts

@@ -23,12 +23,12 @@ export default async function run(
     info(`
     GitHub Pages Deploy Action 🚀
 
-    🚀 Getting Started Guide: https://github.com/marketplace/actions/deploy-to-github-pages
+    💖 Support: https://github.com/sponsors/JamesIves
-    ❓ Discussions / Q&A: https://github.com/JamesIves/github-pages-deploy-action/discussions
-    🔧 Report a Bug: https://github.com/JamesIves/github-pages-deploy-action/issues
-
     📣 Maintained by James Ives: https://jamesiv.es
-    💖 Support: https://github.com/sponsors/JamesIves`)
+
+    🚀 Getting Started Guide: https://github.com/JamesIves/github-pages-deploy-action
+    ❓ Discussions / Q&A: https://github.com/JamesIves/github-pages-deploy-action/discussions
+    🔧 Report a Bug: https://github.com/JamesIves/github-pages-deploy-action/issues`)
 
     info('Checking configuration and starting deployment… 🚦')
 

src/worktree.ts

@@ -43,28 +43,39 @@ export async function generateWorktree(
       action.workspace,
       action.silent
     )
+
     const checkout = new GitCheckout(action.branch)
+
     if (branchExists) {
       // There's existing data on the branch to check out
       checkout.commitish = `origin/${action.branch}`
     }
-    if (!branchExists || action.singleCommit) {
+
-      // Create a new history if we don't have the branch, or if we want to reset it
+    if (
+      !branchExists ||
+      (action.singleCommit && action.branch !== process.env.GITHUB_REF_NAME)
+    ) {
+      /* Create a new history if we don't have the branch, or if we want to reset it.
+        If the ref name is the same as the branch name, do not attempt to create an orphan of it. */
       checkout.orphan = true
     }
+
     await execute(
       checkout.toString(),
       `${action.workspace}/${worktreedir}`,
       action.silent
     )
+
     if (!branchExists) {
       info(`Created the ${action.branch} branch… 🔧`)
+
       // Our index is in HEAD state, reset
       await execute(
         'git reset --hard',
         `${action.workspace}/${worktreedir}`,
         action.silent
       )
+
       if (!action.singleCommit) {
         // New history isn't singleCommit, create empty initial commit
         await execute(