[PATCH] stash: prevent warning about null bytes in input

The no_changes function calls the untracked_files function through
command substitution. untracked_files will return null bytes because it
runs ls-files with the '-z' option.

Bash since version 4.4 warns about these null bytes. As they are not
required for the test that is being done, remove null bytes from the
input.

This warning is triggered when running git stash save -u resulting in
two warnings:

    git-stash: line 43: warning: command substitution: ignored null byte
    in input

Signed-off-by: Kevin Daudt <redacted>
---
 git-stash.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-stash.sh b/git-stash.sh
index 9b6c2da7b..0dcca3cd6 100755
--- a/git-stash.sh
+++ b/git-stash.sh

@@ -39,7 +39,7 @@ fi
 no_changes () {
 	git diff-index --quiet --cached HEAD --ignore-submodules -- "$@" &&
 	git diff-files --quiet --ignore-submodules -- "$@" &&
-	(test -z "$untracked" || test -z "$(untracked_files)")
+	(test -z "$untracked" || test -z "$(untracked_files | tr -d '\0')")
 }
 
 untracked_files () {

-- 
2.14.0.rc1.33.g384a8b271c