git-submodule: provide easy way of adding new submodules

diff --git a/git-submodule.sh b/git-submodule.sh
index 89a388535026258d65ecba3c0dd6de68e2b06cb4..67c78f2d3d9b867dd5e9c989aa6f9c4da1fbd301 100755 (executable)
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -1,13 +1,15 @@
 #!/bin/sh
 #
-# git-submodules.sh: init, update or list git submodules
+# git-submodules.sh: add, init, update or list git submodules
 #
 # Copyright (c) 2007 Lars Hjemli
 
-USAGE='[--quiet] [--cached] [status|init|update] [--] [<path>...]'
+USAGE='[--quiet] [--cached] [add <repo> [-b branch]|status|init|update] [--] [<path>...]'
 . git-sh-setup
 require_work_tree
 
+add=
+branch=
 init=
 update=
 status=
@@ -25,6 +27,18 @@ say()
        fi
 }
 
+# NEEDSWORK: identical function exists in get_repo_base in clone.sh
+get_repo_base() {
+       (
+               cd "`/bin/pwd`" &&
+               cd "$1" || cd "$1.git" &&
+               {
+                       cd .git
+                       pwd
+               }
+       ) 2>/dev/null
+}
+
 #
 # Map submodule path to submodule name
 #
@@ -42,6 +56,11 @@ module_name()
 #
 # Clone a submodule
 #
+# Prior to calling, modules_update checks that a possibly existing
+# path is not a git repository.
+# Likewise, module_add checks that path does not exist at all,
+# since it is the location of a new submodule.
+#
 module_clone()
 {
        path=$1
@@ -65,6 +84,53 @@ module_clone()
        die "Clone of '$url' into submodule path '$path' failed"
 }
 
+#
+# Add a new submodule to the working tree, .gitmodules and the index
+#
+# $@ = repo [path]
+#
+# optional branch is stored in global branch variable
+#
+module_add()
+{
+       repo=$1
+       path=$2
+
+       if test -z "$repo"; then
+               usage
+       fi
+
+       # Turn the source into an absolute path if
+       # it is local
+       if base=$(get_repo_base "$repo"); then
+               repo="$base"
+       fi
+
+       # Guess path from repo if not specified or strip trailing slashes
+       if test -z "$path"; then
+               path=$(echo "$repo" | sed -e 's|/*$||' -e 's|:*/*\.git$||' -e 's|.*[/:]||g')
+       else
+               path=$(echo "$path" | sed -e 's|/*$||')
+       fi
+
+       test -e "$path" &&
+       die "'$path' already exists"
+
+       git-ls-files --error-unmatch "$path" > /dev/null 2>&1 &&
+       die "'$path' already exists in the index"
+
+       module_clone "$path" "$repo" || exit
+       (unset GIT_DIR && cd "$path" && git checkout -q ${branch:+-b "$branch" "origin/$branch"}) ||
+       die "Unable to checkout submodule '$path'"
+       git add "$path" ||
+       die "Failed to add submodule '$path'"
+
+       GIT_CONFIG=.gitmodules git config submodule."$path".path "$path" &&
+       GIT_CONFIG=.gitmodules git config submodule."$path".url "$repo" &&
+       git add .gitmodules ||
+       die "Failed to register submodule '$path'"
+}
+
 #
 # Register submodules in .git/config
 #
@@ -173,6 +239,9 @@ modules_list()
 while case "$#" in 0) break ;; esac
 do
        case "$1" in
+       add)
+               add=1
+               ;;
        init)
                init=1
                ;;
@@ -185,6 +254,14 @@ do
        -q|--quiet)
                quiet=1
                ;;
+       -b|--branch)
+               case "$2" in
+               '')
+                       usage
+                       ;;
+               esac
+               branch="$2"; shift
+               ;;
        --cached)
                cached=1
                ;;
@@ -201,14 +278,27 @@ do
        shift
 done
 
-case "$init,$update,$status,$cached" in
-1,,,)
+case "$add,$branch" in
+1,*)
+       ;;
+,)
+       ;;
+,*)
+       usage
+       ;;
+esac
+
+case "$add,$init,$update,$status,$cached" in
+1,,,,)
+       module_add "$@"
+       ;;
+,1,,,)
        modules_init "$@"
        ;;
-,1,,)
+,,1,,)
        modules_update "$@"
        ;;
-,,*,*)
+,,,1,*)
        modules_list "$@"
        ;;
 *)