Add ability to create .patch files

The feature request

Feature Request:

Summary

Add functionality to GitHub Desktop to create patch files (.patch) from commits, allowing users to export and share changes in a portable format.

Problem Statement

Currently, GitHub Desktop lacks the ability to create patch files directly from the interface. Users who need to:

• Share changes with collaborators who don't have access to the repository
• Apply changes to different repositories or branches
• Create backups of specific changes
• Work with external tools that consume patch files
• Submit changes to projects that prefer patch-based workflows

Must resort to command line tools (git format-patch, git diff) or other external applications, which disrupts the streamlined workflow that GitHub Desktop provides.

Proposed solution

Proposed Solution

Add patch file creation functionality with the following features:

Core Functionality

• Single Commit to Patch: Right-click context menu on commits with "Create Patch File" option
• Multiple Commits to Patch: Select multiple commits and create a single patch file or multiple files
• Range-based Patches: Create patches for commit ranges (e.g., feature branches)
• Unstaged Changes to Patch: Create patches from current working directory changes

User Interface Options

1. Context Menu Integration

   • Right-click on commit(s) → "Export as Patch"
   • Right-click on branch → "Export branch as patches"

2. Menu Bar Option

   • Repository → Export → Create Patch Files

3. File Dialog

   • Allow users to choose save location and filename
   • Default naming: 0001-commit-title.patch (following git format-patch convention)

Advanced Features

• Patch Options:

  • Include/exclude merge commits
  • Add cover letter for patch series
  • Configure patch format (unified diff, context lines)
  • Include binary files option

• Export Formats:

  • Standard Git patch format
  • Unified diff format
  • Option to create individual files or combined patch

Use Cases

1. Code Review and Collaboration

Scenario: Developer needs to share changes with a colleague who doesn't have repository access. Solution: Export commits as patch files and send via email or messaging.

2. Cross-Repository Changes

Scenario: Apply the same fix across multiple similar projects. Solution: Create patch from one repository and apply to others.

3. Backup and Archival

Scenario: Keep offline backups of important changes before major refactoring. Solution: Export critical commits as patch files for safe keeping.

4. Integration with External Tools

Scenario: Use patches with code review tools, IDEs, or deployment systems that consume patch files. Solution: Direct export from GitHub Desktop eliminates manual command-line steps.

Technical Implementation Suggestions

Backend Integration

• Leverage existing libgit2 or Git CLI integration
• Use git format-patch command equivalents
• Ensure compatibility with standard patch formats

UI Components

• Modal dialog for patch options
• Progress indicator for large patch operations
• Success notification with option to open file location

File Handling

• Respect user's default download/export directory
• Handle filename conflicts gracefully
• Support batch operations for multiple commits

Benefits

• Workflow Continuity: Keep users within GitHub Desktop ecosystem
• Accessibility: Make patch creation available to non-command-line users
• Productivity: Reduce context switching between tools
• Standardization: Ensure consistent patch format across team

Additional context

Additional Context

This feature would complement GitHub Desktop's mission of making Git accessible to all developers, regardless of command-line proficiency. Many competing Git GUI applications (GitKraken, Sourcetree, etc.) already offer patch export functionality.