Take --git-dir into consideration during bash completion.

If the user has setup a command line of "git --git-dir=baz" then
anything we complete must be performed within the scope of "baz"
and not the current working directory.

This is useful with commands such as "git --git-dir=git.git log m"
to complete out "master" and view the log for the master branch of
the git.git repository.  As a nice side effect this also works for
aliases within the target repository, just as git would honor them.

Unfortunately because we still examine arguments by absolute position
in most of the more complex commands (e.g. git push) using --git-dir
with those commands will probably still cause completion to fail.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

contrib/completion/git-completion.bash

@@ -19,15 +19,20 @@
 #        source ~/.git-completion.sh
 #
 
+__gitdir ()
+{
+	echo "${__git_dir:-$(git rev-parse --git-dir 2>/dev/null)}"
+}
+
 __git_refs ()
 {
-	local cmd i is_hash=y
-	if [ -d "$1" ]; then
+	local cmd i is_hash=y dir="${1:-$(__gitdir)}"
+	if [ -d "$dir" ]; then
 		cmd=git-peek-remote
 	else
 		cmd=git-ls-remote
 	fi
-	for i in $($cmd "$1" 2>/dev/null); do
+	for i in $($cmd "$dir" 2>/dev/null); do
 		case "$is_hash,$i" in
 		y,*) is_hash=n ;;
 		n,*^{}) is_hash=y ;;
@@ -40,13 +45,13 @@ __git_refs ()
 
 __git_refs2 ()
 {
-	local cmd i is_hash=y
-	if [ -d "$1" ]; then
+	local cmd i is_hash=y dir="${1:-$(__gitdir)}"
+	if [ -d "$dir" ]; then
 		cmd=git-peek-remote
 	else
 		cmd=git-ls-remote
 	fi
-	for i in $($cmd "$1" 2>/dev/null); do
+	for i in $($cmd "$dir" 2>/dev/null); do
 		case "$is_hash,$i" in
 		y,*) is_hash=n ;;
 		n,*^{}) is_hash=y ;;
@@ -59,14 +64,14 @@ __git_refs2 ()
 
 __git_remotes ()
 {
-	local i ngoff IFS=$'\n'
+	local i ngoff IFS=$'\n' d="$(__gitdir)"
 	shopt -q nullglob || ngoff=1
 	shopt -s nullglob
-	for i in .git/remotes/*; do
-		echo ${i#.git/remotes/}
+	for i in "$d/remotes"/*; do
+		echo ${i#$d/remotes/}
 	done
 	[ "$ngoff" ] && shopt -u nullglob
-	for i in $(git repo-config --list); do
+	for i in $(git --git-dir="$d" repo-config --list); do
 		case "$i" in
 		remote.*.url=*)
 			i="${i#remote.}"
@@ -95,7 +100,7 @@ __git_complete_file ()
 			;;
 	    esac
 		COMPREPLY=($(compgen -P "$pfx" \
-			-W "$(git-ls-tree "$ls" \
+			-W "$(git --git-dir="$(__gitdir)" ls-tree "$ls" \
 				| sed '/^100... blob /s,^.*	,,
 				       /^040000 tree /{
 				           s,^.*	,,
@@ -105,7 +110,7 @@ __git_complete_file ()
 			-- "$cur"))
 		;;
 	*)
-		COMPREPLY=($(compgen -W "$(__git_refs .)" -- "$cur"))
+		COMPREPLY=($(compgen -W "$(__git_refs)" -- "$cur"))
 		;;
 	esac
 }
@@ -113,7 +118,7 @@ __git_complete_file ()
 __git_aliases ()
 {
 	local i IFS=$'\n'
-	for i in $(git repo-config --list); do
+	for i in $(git --git-dir="$(__gitdir)" repo-config --list); do
 		case "$i" in
 		alias.*)
 			i="${i#alias.}"
@@ -125,7 +130,8 @@ __git_aliases ()
 
 __git_aliased_command ()
 {
-	local word cmdline=$(git repo-config --get "alias.$1")
+	local word cmdline=$(git --git-dir="$(__gitdir)" \
+		repo-config --get "alias.$1")
 	for word in $cmdline; do
 		if [ "${word##-*}" ]; then
 			echo $word
@@ -137,7 +143,7 @@ __git_aliased_command ()
 _git_branch ()
 {
 	local cur="${COMP_WORDS[COMP_CWORD]}"
-	COMPREPLY=($(compgen -W "-l -f -d -D $(__git_refs .)" -- "$cur"))
+	COMPREPLY=($(compgen -W "-l -f -d -D $(__git_refs)" -- "$cur"))
 }
 
 _git_cat_file ()
@@ -159,7 +165,7 @@ _git_cat_file ()
 _git_checkout ()
 {
 	local cur="${COMP_WORDS[COMP_CWORD]}"
-	COMPREPLY=($(compgen -W "-l -b $(__git_refs .)" -- "$cur"))
+	COMPREPLY=($(compgen -W "-l -b $(__git_refs)" -- "$cur"))
 }
 
 _git_diff ()
@@ -170,7 +176,7 @@ _git_diff ()
 _git_diff_tree ()
 {
 	local cur="${COMP_WORDS[COMP_CWORD]}"
-	COMPREPLY=($(compgen -W "-r -p -M $(__git_refs .)" -- "$cur"))
+	COMPREPLY=($(compgen -W "-r -p -M $(__git_refs)" -- "$cur"))
 }
 
 _git_fetch ()
@@ -188,7 +194,7 @@ _git_fetch ()
 		case "$cur" in
 		*:*)
 	        cur=$(echo "$cur" | sed 's/^.*://')
-			COMPREPLY=($(compgen -W "$(__git_refs .)" -- "$cur"))
+			COMPREPLY=($(compgen -W "$(__git_refs)" -- "$cur"))
 			;;
 		*)
 			local remote
@@ -221,10 +227,10 @@ _git_log ()
 	*..*)
 		local pfx=$(echo "$cur" | sed 's/\.\..*$/../')
 		cur=$(echo "$cur" | sed 's/^.*\.\.//')
-		COMPREPLY=($(compgen -P "$pfx" -W "$(__git_refs .)" -- "$cur"))
+		COMPREPLY=($(compgen -P "$pfx" -W "$(__git_refs)" -- "$cur"))
 		;;
 	*)
-		COMPREPLY=($(compgen -W "$(__git_refs .)" -- "$cur"))
+		COMPREPLY=($(compgen -W "$(__git_refs)" -- "$cur"))
 		;;
 	esac
 }
@@ -232,7 +238,7 @@ _git_log ()
 _git_merge_base ()
 {
 	local cur="${COMP_WORDS[COMP_CWORD]}"
-	COMPREPLY=($(compgen -W "$(__git_refs .)" -- "$cur"))
+	COMPREPLY=($(compgen -W "$(__git_refs)" -- "$cur"))
 }
 
 _git_pull ()
@@ -280,7 +286,7 @@ _git_push ()
 			COMPREPLY=($(compgen -W "$(__git_refs "$remote")" -- "$cur"))
 			;;
 		*)
-			COMPREPLY=($(compgen -W "$(__git_refs2 .)" -- "$cur"))
+			COMPREPLY=($(compgen -W "$(__git_refs2)" -- "$cur"))
 			;;
 		esac
 		;;
@@ -291,56 +297,67 @@ _git_reset ()
 {
 	local cur="${COMP_WORDS[COMP_CWORD]}"
 	local opt="--mixed --hard --soft"
-	COMPREPLY=($(compgen -W "$opt $(__git_refs .)" -- "$cur"))
+	COMPREPLY=($(compgen -W "$opt $(__git_refs)" -- "$cur"))
 }
 
 _git_show ()
 {
 	local cur="${COMP_WORDS[COMP_CWORD]}"
-	COMPREPLY=($(compgen -W "$(__git_refs .)" -- "$cur"))
+	COMPREPLY=($(compgen -W "$(__git_refs)" -- "$cur"))
 }
 
 _git ()
 {
-	if [ $COMP_CWORD = 1 ]; then
+	local i c=1 command __git_dir
+
+	while [ $c -lt $COMP_CWORD ]; do
+		i="${COMP_WORDS[c]}"
+		case "$i" in
+		--git-dir=*) __git_dir="${i#--git-dir=}" ;;
+		--bare)      __git_dir="." ;;
+		--version|--help|-p|--paginate) ;;
+		*) command="$i"; break ;;
+		esac
+		c=$((++c))
+	done
+
+	if [ $c -eq $COMP_CWORD -a -z "$command" ]; then
 		COMPREPLY=($(compgen \
-			-W "--version $(git help -a|egrep '^ ') \
+			-W "--git-dir= --version \
+				$(git help -a|egrep '^ ') \
 			    $(__git_aliases)" \
 			-- "${COMP_WORDS[COMP_CWORD]}"))
-	else
-		local command="${COMP_WORDS[1]}"
-		local expansion=$(__git_aliased_command "$command")
+		return;
+	fi
 
-		if [ "$expansion" ]; then
-			command="$expansion"
-		fi
+	local expansion=$(__git_aliased_command "$command")
+	[ "$expansion" ] && command="$expansion"
 
-		case "$command" in
-		branch)      _git_branch ;;
-		cat-file)    _git_cat_file ;;
-		checkout)    _git_checkout ;;
-		diff)        _git_diff ;;
-		diff-tree)   _git_diff_tree ;;
-		fetch)       _git_fetch ;;
-		log)         _git_log ;;
-		ls-remote)   _git_ls_remote ;;
-		ls-tree)     _git_ls_tree ;;
-		merge-base)  _git_merge_base ;;
-		pull)        _git_pull ;;
-		push)        _git_push ;;
-		reset)       _git_reset ;;
-		show)        _git_show ;;
-		show-branch) _git_log ;;
-		whatchanged) _git_log ;;
-		*)           COMPREPLY=() ;;
-		esac
-	fi
+	case "$command" in
+	branch)      _git_branch ;;
+	cat-file)    _git_cat_file ;;
+	checkout)    _git_checkout ;;
+	diff)        _git_diff ;;
+	diff-tree)   _git_diff_tree ;;
+	fetch)       _git_fetch ;;
+	log)         _git_log ;;
+	ls-remote)   _git_ls_remote ;;
+	ls-tree)     _git_ls_tree ;;
+	merge-base)  _git_merge_base ;;
+	pull)        _git_pull ;;
+	push)        _git_push ;;
+	reset)       _git_reset ;;
+	show)        _git_show ;;
+	show-branch) _git_log ;;
+	whatchanged) _git_log ;;
+	*)           COMPREPLY=() ;;
+	esac
 }
 
 _gitk ()
 {
 	local cur="${COMP_WORDS[COMP_CWORD]}"
-	COMPREPLY=($(compgen -W "--all $(__git_refs .)" -- "$cur"))
+	COMPREPLY=($(compgen -W "--all $(__git_refs)" -- "$cur"))
 }
 
 complete -o default -o nospace -F _git git