Git submodule helper scripts & gui

A collection of scripts that should help make life with git submodules easier. They are aimed at the case with a central repository. The submodules are thought not only as quasi static repositories, but as something where active development happens. The scripts support two levels of submodules, but most scripts do not support more than that.

gitR is a simple graphical interface that should make working with submodules even easier. It only covers the basic functionality required for an average user. The main advantage in working with the graphical interface lies in the way the status of the repository is presented: the user always sees the full status of the repository and the submodules without the need to actively query for it.

How to use

The standard (one-person-working) work flow is as follows:

• Clone the repository using git rclone.
• Work and commit in the repository and its submodules as if there was nothing special about them.
• Prepare repository to be published by using git rcommit -am "msg".
• Publish your work to central server using git rpush.

Using tags (and branches):

• Create tags in the super repository using git tag as usual.
• Switch to tags using git rcheckout in the super repository.

The same can be done for branches - at least in theory. The scripts were not developed with this case in mind. Note that there are no scripts that help with the creation or merging of branches for all submodules or something similar (on purpose, how would you do that?). The scripts will just try to attach the HEAD to the correct branch if the submodules feature different branches.

Working together

Then there are a couple of scripts that help to recover from conflicts that will probably arise when working simultaneously at the same super repository.

• Pull changes in super repository using git rpull. This will also update submodules, if necessary.
• Check submodules for updates using git rfetch --dry-run and fetch them using git rfetch.
• Get a diff like master..origin for all submodules using git rdiff.
• Then incorporate the updates with git pull in the submodules.
• If the branches have diverged, e.g., when there are new local commits and in the central repository as well, use git converge-submodules to get rid of submodule conflicts in super repositories. (Note that if there are submodules on two levels, the command probably needs to be run only for the first level submodules. The super repository will resolve the conflict automatically when rcommitting.)

See also tests.sh for an example work flow on how to recover from conflicts.

Main scripts

Commands that start with an "r" (for "recursive") followed by some familiar git command name are do just what they should do, but with some added functionality that should simplify the work with submodules.

• git-rclone: clone repository and avoid detached head state ("attach heads").
• git-rpush: push super and sub repositories starting with the innermost submodules.
• git-rpull: pull super repository and update submodules, initializes added and removes removes submodules. Attaches head if possible.
• git-rcheckout: checkout super repository and update submodules, initializes added and removes deleted submodules. Attaches head if possible.
• git-rcommit: runs the same commit command starting with the innermost submodules. This is thought to be used with -a so one can quickly create commits to update all pointers to submodules.
• git-rfetch: does a git fetch for the super repository and all submodules. Accepts the argument --dry-run to check for updates without really downloading them.
• git-rdiff: show the differences between local and remote rep. Thought to help after a 'git rfetch`. Does show differences only for regular files, not submodule pointers.
• git-converge-submodules: to resolve a situation where local and remote branches have diverged, "if divergent force convergence". Basically run a git pull (only if necessary). Does a little more if just submodule pointers are involved, like removing clean submodules.
• git-rm-submodule: remove a submodule in git's config and in the working copy. Commits the removal of the submodule if the argument --no-commit is not given.
• git-mv-submodule: move a submodule, also has a --no-commit argument.
• git-fix-submodules: script to fix up the submodules in a repository.

Helper Scripts

Some commands that are just thought to be used internally.

• git-ccomit: conditional commit. Only commit if there is something to commit. Warns if there are unstaged changes to tracked files. Runs git converge-submodules afterwards to avoid diverged branches.
• git-cpush: conditional push: only push if the local branch is ahead.
• git-rm-orphaned-submodule-dirs: remove orphaned submodule directories.
• git-attach-head: if a repository is in detached head state, but the HEAD just points to a tip of a branch, check out this branch. If necessary, the local branch is fast forwarded. Otherwise we stay in the detached head state.
• git-check-branch: checks if the current checked out branch is a remote tracking branch. Fails if not or if rep. is in detached head state.
• git-check-clean: checks if a repository is clean and if not reports in what way: changes to submodules, staged, unstaged or unmerged changes to tracked files and untracked files. Either checks for all of them or only for the given arguments: --unmerged, --unstaged, --uncommitted, --untracked. Returns exit code if --exit-code is given. The argument --ignore-submodules is the same as for git status.
• git-check-unpushed: checks for any unpushed remote tracking branch.
• git-check-non-tracking: checks if there are any non-tracking branches.
• git-bfetch: calls git fetch, but shows only output for the currently checked out branch.

Other Stuff

• The script tests.sh can be used to test the scripts.
• The script gen-man.sh can be used to generate man pages.
• Update hook hooks/update can be used to prevent pushing of commits containing references to submodule commits which have not been pushed.

Installation

The scripts can be placed anywhere in $PATH, e.g., /usr/local/bin.

gitR requires an current R installation (http://www.r-project.org) and requires the R-package (contained in gitR-package/) to be installed. Before installing the package, make sure to have installed the R-packages

• gWidgets,
• gWidgetsRGtk2,
• gtools,
• RGtk2. For example by running the R-command: install.packages(c("gWidgetsRGtk2", "gtools"), dependencies="Depends") After that, the gitR-package can be installed by running R CMD INSTALL gitR-package in the root of this repository.

Known Problems

• Scripts should be called in the same directory as where the .git and .gitmodules files lie. Otherwise the scripts might incorrectly assume that there are not submodules.
• Scripts are slow.
• Scripts of master branch do not work on OS X, this because xargs there does not allow for an -r argument (use no xargs-branch).
• When invoking git rcommit without giving the message, the shell somehow breaks afterwards and has to be restarted.
• The scripts work fine for git versions 1.7.6.1, 1.7.7.3 and 1.7.10.1, but there are some known problems with 1.7.8.4 and 1.7.9.4.

Copyright/License

License: GPL v2 Copyright (c) 2012 Manuel Koller