[PATCH] Simple update to bash completions to prevent unbound variable errors.

[Ted Pavlic <ted@tedpavlic.com>]

Below is a cleaner patch that prevents problems with unbound arguments
when bash is being operated under "set -u."

Some comments were added to remind callers about the requirements of
each __git* utility function.

Additionally, the completion call to bash has been modernized a bit.

A vim modeline has also been added for consistency.

Signed-off-by: Ted Pavlic <ted@tedpavlic.com>
---
  contrib/completion/git-completion.bash |   70 
+++++++++++++++++++++++++-------
  1 files changed, 55 insertions(+), 15 deletions(-)

diff --git a/contrib/completion/git-completion.bash 
b/contrib/completion/git-completion.bash
index 7b074d7..619e886 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -50,9 +50,11 @@ case "$COMP_WORDBREAKS" in
  *)   COMP_WORDBREAKS="$COMP_WORDBREAKS:"
  esac

+# __gitdir accepts 0 or 1 arguments (i.e., location)
+# returns location of .git repo
  __gitdir ()
  {
-	if [ -z "$1" ]; then
+	if [ $# -eq 0 ] || [ -z "$1" ]; then
  		if [ -n "$__git_dir" ]; then
  			echo "$__git_dir"
  		elif [ -d .git ]; then
@@ -67,6 +69,8 @@ __gitdir ()
  	fi
  }

+# __git_ps1 accepts 0 or 1 arguments (i.e., format string)
+# returns text to add to bash PS1 prompt (includes branch name)
  __git_ps1 ()
  {
  	local g="$(git rev-parse --git-dir 2>/dev/null)"
@@ -111,7 +115,7 @@ __git_ps1 ()
  			fi
  		fi

-		if [ -n "$1" ]; then
+		if [ $# -gt 0 ] && [ -n "$1" ]; then
  			printf "$1" "${b##refs/heads/}$r"
  		else
  			printf " (%s)" "${b##refs/heads/}$r"
@@ -119,6 +123,7 @@ __git_ps1 ()
  	fi
  }

+# __gitcomp_1 requires 2 arguments
  __gitcomp_1 ()
  {
  	local c IFS=' '$'\t'$'\n'
@@ -131,11 +136,22 @@ __gitcomp_1 ()
  	done
  }

+# __gitcomp accepts 1, 2, 3, or 4 arguments
+# generates completion reply with compgen
  __gitcomp ()
  {
-	local cur="${COMP_WORDS[COMP_CWORD]}"
-	if [ $# -gt 2 ]; then
-		cur="$3"
+	local one two cur="${COMP_WORDS[COMP_CWORD]}" four
+	if [ $# -gt 0 ]; then
+		one="$1"
+		if [ $# -gt 1 ]; then
+			two="$2"
+			if [ $# -gt 2 ]; then
+				cur="$3"
+				if [ $# -gt 3 ]; then
+					four="$4"
+				fi
+			fi
+		fi
  	fi
  	case "$cur" in
  	--*=)
@@ -143,22 +159,27 @@ __gitcomp ()
  		;;
  	*)
  		local IFS=$'\n'
-		COMPREPLY=($(compgen -P "$2" \
-			-W "$(__gitcomp_1 "$1" "$4")" \
+		COMPREPLY=($(compgen -P "$two" \
+			-W "$(__gitcomp_1 "$one" "$four")" \
  			-- "$cur"))
  		;;
  	esac
  }

+# __git_heads accepts 0 or 1 arguments (to pass to __gitdir)
  __git_heads ()
  {
-	local cmd i is_hash=y dir="$(__gitdir "$1")"
+	local one
+	if [ $# -gt 0 ]; then
+		one="$1"
+	fi
+	local cmd i is_hash=y dir="$(__gitdir "$one")"
  	if [ -d "$dir" ]; then
  		git --git-dir="$dir" for-each-ref --format='%(refname:short)' \
  			refs/heads
  		return
  	fi
-	for i in $(git ls-remote "$1" 2>/dev/null); do
+	for i in $(git ls-remote "$one" 2>/dev/null); do
  		case "$is_hash,$i" in
  		y,*) is_hash=n ;;
  		n,*^{}) is_hash=y ;;
@@ -168,15 +189,20 @@ __git_heads ()
  	done
  }

+# __git_tags accepts 0 or 1 arguments (to pass to __gitdir)
  __git_tags ()
  {
-	local cmd i is_hash=y dir="$(__gitdir "$1")"
+	local one
+	if [ $# -gt 0 ]; then
+		one="$1"
+	fi
+	local cmd i is_hash=y dir="$(__gitdir "$one")"
  	if [ -d "$dir" ]; then
  		git --git-dir="$dir" for-each-ref --format='%(refname:short)' \
  			refs/tags
  		return
  	fi
-	for i in $(git ls-remote "$1" 2>/dev/null); do
+	for i in $(git ls-remote "$one" 2>/dev/null); do
  		case "$is_hash,$i" in
  		y,*) is_hash=n ;;
  		n,*^{}) is_hash=y ;;
@@ -186,9 +212,14 @@ __git_tags ()
  	done
  }

+# __git_refs accepts 0 or 1 arguments (to pass to __gitdir)
  __git_refs ()
  {
-	local i is_hash=y dir="$(__gitdir "$1")"
+	local one
+	if [ $# -gt 0 ]; then
+		one="$1"
+	fi
+	local i is_hash=y dir="$(__gitdir "$one")"
  	local cur="${COMP_WORDS[COMP_CWORD]}" format refs
  	if [ -d "$dir" ]; then
  		case "$cur" in
@@ -218,6 +249,7 @@ __git_refs ()
  	done
  }

+# __git_refs2 requires 1 argument (to pass to __git_refs)
  __git_refs2 ()
  {
  	local i
@@ -226,6 +258,7 @@ __git_refs2 ()
  	done
  }

+# __git_refs_remotes requires 1 argument (to pass to ls-remote)
  __git_refs_remotes ()
  {
  	local cmd i is_hash=y
@@ -470,6 +503,7 @@ __git_aliases ()
  	done
  }

+# __git_aliased_command requires 1 argument
  __git_aliased_command ()
  {
  	local word cmdline=$(git --git-dir="$(__gitdir)" \
@@ -482,6 +516,7 @@ __git_aliased_command ()
  	done
  }

+# __git_find_subcommand requires 1 argument
  __git_find_subcommand ()
  {
  	local word subcommand c=1
@@ -1766,13 +1801,18 @@ _gitk ()
  	__git_complete_revlist
  }

-complete -o default -o nospace -F _git git
-complete -o default -o nospace -F _gitk gitk
+complete -o bashdefault -o default -o nospace -F _git git 2>/dev/null \
+	|| complete -o default -o nospace -F _git git
+complete -o bashdefault -o default -o nospace -F _gitk gitk 2>/dev/null \
+	|| complete -o default -o nospace -F _gitk gitk

  # The following are necessary only for Cygwin, and only are needed
  # when the user has tab-completed the executable name and consequently
  # included the '.exe' suffix.
  #
  if [ Cygwin = "$(uname -o 2>/dev/null)" ]; then
-complete -o default -o nospace -F _git git.exe
+complete -o bashdefault -o default -o nospace -F _git git.exe 2>/dev/null \
+	|| complete -o default -o nospace -F _git git.exe
  fi
+
+# vim:ft=sh:fdm=marker:ff=unix:noet:ts=4:sw=4
-- 
1.6.1.87.g15624