# Default PR Title and Body from Commit Message

When creating a pull request with a single commit, the action will automatically default the PR title and body to match the commit message, similar to how GitHub's web interface behaves.

## Behavior

### Single Commit PRs

When the following conditions are met:
- The pull request branch contains exactly **one commit**
- The `title` input is not provided (uses default value)
- The `body` input is not provided (uses default value)

The action will:
- Use the commit's **subject line** as the PR title
- Use the commit's **body** as the PR description (if the commit has a body)

### Example

Given a commit with this message:
```
Update AGP sources to the latest

_Auto-generated by `dump-sources` Github workflow._
```

The following workflow configuration:
```yml
- uses: peter-evans/create-pull-request@v7
  with:
    commit-message: |
      Update AGP sources to the latest

      _Auto-generated by `dump-sources` Github workflow._
    branch: actions/dump-sources
    delete-branch: true
```

Will create a pull request with:
- **Title**: `Update AGP sources to the latest`
- **Body**: `_Auto-generated by `dump-sources` Github workflow._`

### Multiple Commits

When the pull request branch contains **multiple commits**, the action will use the default values:
- **Title**: `Changes by create-pull-request action`
- **Body**: `Automated changes by [create-pull-request](https://github.com/peter-evans/create-pull-request) GitHub action`

### Custom Title and Body

If you explicitly provide `title` or `body` inputs, those values will always be used regardless of the number of commits:

```yml
- uses: peter-evans/create-pull-request@v7
  with:
    commit-message: |
      Update AGP sources to the latest

      _Auto-generated by `dump-sources` Github workflow._
    title: Custom PR Title
    body: Custom PR Description
    branch: actions/dump-sources
```

This will create a PR with your custom title and body, ignoring the commit message.

## Benefits

This feature eliminates the need to duplicate commit messages in the workflow configuration:

### Before (Duplicated Content)
```yml
- uses: peter-evans/create-pull-request@v7
  with:
    commit-message: |
      Update AGP sources to the latest

      _Auto-generated by `dump-sources` Github workflow._
    title: Update AGP sources to the latest
    body: _Auto-generated by `dump-sources` Github workflow._
    branch: actions/dump-sources
```

### After (Simplified)
```yml
- uses: peter-evans/create-pull-request@v7
  with:
    commit-message: |
      Update AGP sources to the latest

      _Auto-generated by `dump-sources` Github workflow._
    branch: actions/dump-sources
```

## Edge Cases

### Commit with Empty Body

If a commit has only a subject line (no body), the PR will use:
- **Title**: The commit subject
- **Body**: The default body text

Example commit:
```
Update files
```

Results in:
- **Title**: `Update files`
- **Body**: `Automated changes by [create-pull-request](https://github.com/peter-evans/create-pull-request) GitHub action`

### Commit with Multi-line Body

Multi-line commit bodies are fully preserved in the PR description:

Example commit:
```
Update documentation

This is a detailed commit message.

It has multiple paragraphs.

- Item 1
- Item 2
```

Results in a PR with the full multi-line body as the description.