t3404 static check of bad SHA-1 failure

Hello,

in t3404 test 91 - static check of bad SHA-1 fails (with ksh) with a syntax error in git-rebase. git-rebase[6]: test: argument expected

Reason is, again, a test -z without quotes in git-rebase--interactive:
*** ../git-rebase--interactive.orig     Tue May 10 17:36:59 2016
--- ../git-rebase--interactive  Fri May 13 17:57:27 2016
***************
*** 870,876 ****
                badsha=1
        else
                sha1_verif="$(git rev-parse --verify --quiet $1^{commit})"
!               if test -z $sha1_verif
                then
                        badsha=1
                fi
--- 870,876 ----
                badsha=1
        else
                sha1_verif="$(git rev-parse --verify --quiet $1^{commit})"
!               if test -z "$sha1_verif"
                then
                        badsha=1
                fi

Maybe it would be a good idea, to quote the test -z $1 in the same function check_commit_sha too. The test completes successfully without it, but since it's an user option, I think it should be quoted. Then there would be no more unquoted test -z anymore :-)

Armin