Merge branch 'jk/test-z-n-unquoted'

t9xxx series has been updated primarily for readability, while
fixing small bugs in it.  A few scripted Porcelains have also been
updated to fix possible bugs around their use of "test -z" and
"test -n".

* jk/test-z-n-unquoted:
always quote shell arguments to test -z/-n
t9103: modernize test style
t9107: switch inverted single/double quotes in test
t9107: use "return 1" instead of "exit 1"
t9100,t3419: enclose all test code in single-quotes
t/lib-git-svn: drop $remote_git_svn and $git_svn_id

diff --combined git-rebase--interactive.sh
index 1c6dfb6d5618f43eaac1c279332d33e6a913c2d9,470413b9f9b603b8f9fe8718607bf66f6c794cdf..9d2bfb7a16afc10c1a52fe80e718d6199df0e331
--- 1/git-rebase--interactive.sh
--- 2/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@@ -82,7 -82,6 +82,7 @@@ rewritten_pending="$state_dir"/rewritte
  cr=$(printf "\015")
  
  strategy_args=${strategy:+--strategy=$strategy}
 +test -n "$strategy_opts" &&
  eval '
        for strategy_opt in '"$strategy_opts"'
        do
@@@ -867,12 -866,12 +867,12 @@@ add_exec_commands () 
  # $3: the input filename
  check_commit_sha () {
        badsha=0
-       if test -z $1
+       if test -z "$1"
        then
                badsha=1
        else
                sha1_verif="$(git rev-parse --verify --quiet $1^{commit})"
-               if test -z $sha1_verif
+               if test -z "$sha1_verif"
                then
                        badsha=1
                fi