Attaching patches to Pull Requests
This might sound strange, but sometimes I prefer patches to pull requests. The main scenario is when I’m reviewing someone else’s code and I want to propose an alternative implementation.
I could just create a new branch and pull request with my change, but then the conversation is split between two PRs, and there’s a new branch that you have to clean up.
When the change is small enough, or I’m not sure if it will be accepted, I’d rather send a patch. So far I’ve been doing
git diff, uploading the result to gist, and posting the link as a comment in the PR. This has a few shortcomings:
- No binary support.
- If the original author wants to use it, authorship is usually lost, unless they use the
git commit, and even then there’s room for typos.
I know there’s a better way, as Git was originally designed to share patches, not pull requests. I think I’ve been avoiding it because it’s not as common and the original author might not know what to do with the patch. So I’m writing this as a quick tutorial.
Creating a patch
Before creating a patch, you have to commit your changes.
git format-patch will create a patch file for each commit, so your history can be preserved. Once you have a commit, your branch is ahead of origin, so we can use that to tell
format-patch which commits to pick
branch=git rev-parse --abbrev-ref HEAD origin="origin/$branch" git format-patch $origin
This will leave one or more
.patch files in your project directory:
$ ls *.patch 0001-Store-relative-paths-for-reader-topics.patch
Upload those to Gist and leave a comment with the link on the PR:
$ gist -co *.patch
Applying a patch
For a single patch, you can copy the Raw link in the Gist and download it
$ curl -sLO https://gist.github.com/koke/1b30d861e6bb9d366f69bc186d0e9525/raw/8cc27f3e589a7823b2e9f1746aa921b92da14187/0001-Store-relative-paths-for-reader-topics.patch
If there are multiple files, make sure you use the Download Zip link (or download all the files one by one):
$ curl -sLo patches.zip https://gist.github.com/koke/ab100907c17c4ef6a977350494679091/archive/3fb0136a21a6bc499bff2511750c62ae6dc41630.zip $ unzip -j patches.zip Archive: patches.zip 3fb0136a21a6bc499bff2511750c62ae6dc41630 inflating: 0001-Store-relative-paths-for-reader-topics.patch inflating: 0002-Whitespace-changes.patch
Once you have the patch file(s) in your project directory, just run
git am -s *.patch:
$ git am -s *.patch Applying: Store relative paths for reader topics Applying: Whitespace changes
Review the changes, and if you’re happy with them,
git push them. Otherwise, you can reset your branch to point at the pushed changes:
branch=git rev-parse --abbrev-ref HEAD origin="origin/$branch" git reset --hard $origin
git clean -df, or manually remove the downloaded files.