This document explains some conventions and specificities in the way we manage the Symfony code with Git.
Whenever a pull request is merged, all the information contained in the pull request (including comments) is saved in the repository.
You can easily spot pull request merges as the commit message always follows this pattern:
merged branch USER_NAME/BRANCH_NAME (PR #1111)
The PR reference allows you to have a look at the original pull request on GitHub: https://github.com/symfony/symfony/pull/1111. But all the information you can get on GitHub is also available from the repository itself.
The merge commit message contains the original message from the author of the changes. Often, this can help understand what the changes were about and the reasoning behind the changes.
Moreover, the full discussion that might have occurred back then is also stored as a Git note (before March 22 2013, the discussion was part of the main merge commit message). To get access to these notes, add this line to your .git/config file:
fetch = +refs/notes/*:refs/notes/*
After a fetch, getting the GitHub discussion for a commit is then a matter of adding --show-notes=github-comments to the git show command:
$ git show HEAD --show-notes=github-comments