[PATCH 0/2] Don't delete untracked submodule's .git dirs by default

[Jason Holden <jason.k.holden@gmail.com>]

Git-clean is not safe when there is a submodule tracked in a local branch that
is not tracked in the mainline branch. Running git-clean from the mainline
branch when we have unpushed changes in a submodule tracked only in a local
branch can lose local changes to that submodule permanentely.

I have accidentally lost changes in this way when working with very 
large projects where a git-clean is more reliable than a makefile's 
"make clean". 

By changing the default behavior of git-clean to not delete the .git
directories allows the history of the submodules to be recovered.

# Example of issue:
#
# Clone mainline project
git clone git://github.com/thoughtbot/paperclip.git           
cd paperclip/

# Add a submodule not tracked by mainline
git checkout -b test_submodule_clean
git submodule add git://github.com/technoweenie/attachment_fu.git attachement_fu
git commit -m "add submodule"

# Make a modification to the submodule.  Note that we haven't pushed the change
cd attachement_fu/
git checkout -b mod_readme_in_submodule
vi README 
git add README
git commit -m "Small change in submodule"

# Go back to mainline's master branch and do a clean
cd ..
git checkout master
git clean -f -d

# Our change to the submodule, that was never pushed, is now gone forever 
# because all the history stored in the submodule's .git direct is deleted.
# There is no recovering from this.
# This breaks the "git must be safe" rule, as we've lost potentially a lot of
# changes to any submodule projects that didn't get pushed yet. Solve
# this issue by not deleting any .git directories we come across during a
# git-clean, unless the "-m" option is passed to git-clean.

This is my first email submittal using git, so apologies in advance for any
formatting issues

Jason Holden (2):
  Add option to not delete a .git directory in remove_dir_recursively()
  Don't clean any untracked submodule's .git dir by default in
    git-clean

 Documentation/git-clean.txt |    6 +++++-
 builtin-clean.c             |   15 +++++++++++++--
 builtin-clone.c             |    4 ++--
 dir.c                       |   17 +++++++++++++++--
 dir.h                       |    2 +-
 refs.c                      |    2 +-
 transport.c                 |    4 ++--
 7 files changed, 39 insertions(+), 11 deletions(-)