Suggest allowing git rebase --interactive todo lines to take options

Author: mhagger

SoC-2014-Ideas.md

@@ -194,3 +194,64 @@ and repair broken history.
 - Language: C, optional choice of scripting language
 - Difficulty: medium
 - Possible mentors: Jeff King / Michael Haggerty
+
+## Line options for `git rebase --interactive`
+
+One of the more powerful features in Git is the command `git rebase
+--interactive`, which allows recent commits to be reordered, squashed
+together, or even revised completely. The command creates a todo list
+and opens it in an editor. The original todo list might look like:
+
+pick deadbee Implement feature XXX
+pick c0ffeee The oneline of the next commit
+pick 01a01a0 This change is questionable
+pick f1a5c00 Fix to feature XXX
+pick deadbab The oneline of the commit after
+
+The user can edit the list to make changes to the history, for example
+to
+
+pick deadbee Implement feature XXX
+squash f1a5c00 Fix to feature XXX
+exec make
+edit c0ffeee The oneline of the next commit
+pick deadbab The oneline of the commit after
+
+This would cause commits `deadbee` and `f1a5c00` to be squashed
+together into one commit followed by running `make` to test-compile
+the results, delete commit `01a01a0` altogether, and stop after
+committing commit `c0ffeee` to allow the user to make changes.
+
+It would be nice to support more flexibility in the todo-list commands
+by allowing the commands to take options. Maybe
+
+* Convert a commit into a merge commit:
+
+pick -p c0ffeee -p e1ee712 deadbab The oneline of the commit after
+
+* After squashing two commits, add a "Signed-off-by" line to the
+ commit log message:
+
+ pick deadbee Implement feature XXX
+ squash --signoff f1a5c00 Fix to feature XXX
+
+ or GPG-sign a commit:
+
+ pick --gpg-sign=<keyid> deadbee Implement feature XXX
+
+* Reset the author of the commit to the current user or a specified
+ user:
+
+ pick --reset-author deadbee Implement feature XXX
+ pick --author="A U Thor <[email protected]>" deadbab The oneline of the commit after
+
+The goal of this project would be (1) to add the infrastructure for
+handling options on todo-list lines, and (2) implement some concrete
+options. A big part of the difficulty of this project is that `git
+rebase --interactive` is implemented via a sparsely-commented shell
+script. Adding comments and cleaning up the script as you go would be
+very welcome.
+
+- Language: sh
+- Difficulty: medium
+- Possible mentors: Michael Haggerty