git-fix-submodules

#!/bin/bash -e
## Fix submodules: make sure all submodules
## are checked out correctly

## read input, display help if necessary
if [[ "$@" == *--help* ]]; then
    cat<<EOF
 Fix submodules

 This command updates and initializes all submodules.
 Orphaned submodule directories are removed if they are clean. The
 HEADs of submodules are attached if necessary and possible. 

 Usage:
    git fix-submodules [--skip-checks]

    --skip-checks: skip safety checks
EOF
    exit 0;
fi

## from the git mailinglist:
function git
{
    LC_MESSAGES=C command git "$@"
} 
export git

## ensure we are in the toplevel directory
cdup=$(git rev-parse --show-toplevel) &&
cd "$cdup" || {
    echo >&2 "Cannot chdir to $cdup, the toplevel of the working tree"
    exit 1
}

## check for modified content and uncommitted changes
if [[ "$@" != *--skip-checks* ]]; then
    git check-clean || exit 1
fi

## remove orphaned submodule directories
git rm-orphaned-submodule-dirs || exit 1

## continue only if there are submodules
if [ -f .gitmodules ]; then 
    ## update / initialize submodules
    git submodule --quiet update --init || exit 1
    ## do the same for the submodules
    #git submodule --quiet foreach git fix-submodules "$@"
    CMD='cd "$1"; git fix-submodules '"$@"
    git submodule --quiet foreach 'echo "$toplevel/$path"' | 
    xargs -r -n1 -P5 bash -c "$CMD" xargs
    ## attach heads if possible
    #git submodule --quiet foreach git attach-head
    git submodule --quiet foreach 'echo "$toplevel/$path"' | 
    xargs -r -n1 -P5 bash -c 'cd "$1"; git attach-head' xargs
fi