[PATCH] bash-completion: Support running with set -u in bash 4.0

[Jonathan Nieder <jrnieder@gmail.com>]

From: Thomas Nilsson <thomas.nilsson@unixangst.com>
Date: Tue, 23 Feb 2010 12:13:00 +0100

Starting with bash 4.0-beta, under "set -u" semantics, accessing
undefined local variables is now an error.  Some user environments
enable this setting in the interactive shell, with unpleasant results:

 knirch@traktor:~/source/external/git (master)$ set -o unset
 bash: w: unbound variable
 knirch@traktor:~/source/external/git$ git ^Ibash: command: unbound variable
 bash: w: unbound variable
 knirch@traktor:~/source/external/git$
 bash: w: unbound variable
 knirch@traktor:~/source/external/git$

Most of these variables should be bound to "".  In contexts where the
completion functions should access an undefined variable, accessing a
default empty string (as in "${1-}" instead of "$1") is a reasonable
way to cope, as it silences the undefined variable error while still
supplying an empty string.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Sent by Thomas to <http://bugs.debian.org/571087> (thanks!).  One
might use 'set -u' in an interactive shell while manually
single-stepping through a shell script, perhaps.

 contrib/completion/git-completion.bash |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index fe93747..d97467e 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -84,8 +84,8 @@ __git_ps1 ()
 {
 	local g="$(__gitdir)"
 	if [ -n "$g" ]; then
-		local r
-		local b
+		local r=""
+		local b=""
 		if [ -f "$g/rebase-merge/interactive" ]; then
 			r="|REBASE-i"
 			b="$(cat "$g/rebase-merge/head-name")"
@@ -127,11 +127,11 @@ __git_ps1 ()
 			}
 		fi
 
-		local w
-		local i
-		local s
-		local u
-		local c
+		local w=""
+		local i=""
+		local s=""
+		local u=""
+		local c=""
 
 		if [ "true" = "$(git rev-parse --is-inside-git-dir 2>/dev/null)" ]; then
 			if [ "true" = "$(git rev-parse --is-bare-repository 2>/dev/null)" ]; then
@@ -2181,7 +2181,7 @@ _git ()
 		c=$((++c))
 	done
 
-	if [ -z "$command" ]; then
+	if [ -z "${command-}" ]; then
 		case "${COMP_WORDS[COMP_CWORD]}" in
 		--*)   __gitcomp "
 			--paginate
-- 
1.7.0