ci: make backport releases possible

.github/workflows/prepare-release.yml

@@ -3,6 +3,11 @@ name: Prepare Release
 on:
   workflow_dispatch:
     inputs:
+      target_branch:
+        description: Release target branch
+        required: true
+        default: main
+        type: string
       package:
         description: Package to release
         required: true
@@ -31,7 +36,7 @@ on:
         type: string
 
 concurrency:
-  group: ${{ github.workflow }}-${{ inputs.package }}-${{ inputs.version || inputs.release }}
+  group: ${{ github.workflow }}-${{ inputs.target_branch }}-${{ inputs.package }}-${{ inputs.version || inputs.release }}
   cancel-in-progress: false
 
 permissions: {}
@@ -45,10 +50,19 @@ jobs:
       contents: write
       pull-requests: write
     steps:
+      - name: Validate target branch
+        env:
+          TARGET_BRANCH: ${{ inputs.target_branch }}
+        run: |
+          if [[ "$TARGET_BRANCH" != "main" && ! "$TARGET_BRANCH" =~ ^v[0-9]+(\.[0-9]+)?$ ]]; then
+            echo "Target branch must be main or a v* release branch (for example, v8 or v8.0)"
+            exit 1
+          fi
+
       - name: Checkout
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
-          ref: main
+          ref: ${{ inputs.target_branch }}
           fetch-depth: 0
           persist-credentials: false
 
@@ -82,4 +96,5 @@ jobs:
           package-path: packages/${{ inputs.package }}
           pr-body: ${{ steps.prepare.outputs.pr_body }}
           tag: ${{ steps.prepare.outputs.tag }}
+          target-branch: ${{ inputs.target_branch }}
           version: ${{ steps.prepare.outputs.version }}

.github/workflows/publish.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - main
+      - "v[0-9]*"
 
 permissions: {}
 

CONTRIBUTING.md

@@ -352,14 +352,15 @@ All publishable packages in this repository use a pull-request-driven release fl
 #### Prepare a Release
 
 1. Run the [Prepare Release](.github/workflows/prepare-release.yml) workflow from the `main` branch.
-2. Select `vite`, `create-vite`, or `plugin-legacy`.
-3. Select a `release` type. The default `next` creates the next patch for a stable version or advances an existing prerelease. Alternatively, select another supported release type or enter an exact `version`, which takes precedence over `release`.
-4. Wait for the action to open the release PR. The PR contains the selected package's version bump and changelog entry. A `create-vite` release also updates template Vite dependency versions when appropriate.
+2. Enter the target branch. Use `main` for the current release line or a `v*` release branch (for example, `v8` or `v8.0`) for a patch release.
+3. Select `vite`, `create-vite`, or `plugin-legacy`.
+4. Select a `release` type. The default `next` creates the next patch for a stable version or advances an existing prerelease. Alternatively, select another supported release type or enter an exact `version`, which takes precedence over `release`.
+5. Wait for the action to open a release PR against the target branch. The PR contains the selected package's version bump and changelog entry. A `create-vite` release also updates template Vite dependency versions when appropriate.
 
 #### Review and Publish
 
 1. Review the generated version and changelog, and wait for the release PR checks to pass.
-2. Merge the PR while retaining its `release: <tag>` commit subject. Vite uses `release: v<version>`; other packages use `release: <package>@<version>`. A matching commit at the tip of `main` triggers the publish job.
+2. Merge the PR while retaining its `release: <tag>` commit subject. Vite uses `release: v<version>`; other packages use `release: <package>@<version>`. A matching commit at the tip of `main` or a `v*` release branch triggers the publish job.
 3. Open the [Publish Package](.github/workflows/publish.yml) run and approve its `Release` environment deployment.
 4. Wait for the workflow to publish the package, create its tag, and create the corresponding GitHub release.
 5. Verify the new version on npm.
@@ -368,7 +369,7 @@ All publishable packages in this repository use a pull-request-driven release fl
 
 The release flow depends on configuration outside this repository:
 
-- The `Release` environment must require maintainer approval before publishing.
+- The `Release` environment must require maintainer approval before publishing and allow deployments from `main` and supported `v*` release branches.
 - The npm trusted publishers for `vite`, `create-vite`, and `@vitejs/plugin-legacy` must be restricted to `vitejs/vite`, `.github/workflows/publish.yml`, and the `Release` environment.
 
 #### Recovery