test "$(sed -e "s/^\(.........\).*/\1/" actual | sort -u)" = 000000000
'
+test_expect_success 'ambiguous 40-hex ref' '
+ TREE=$(git mktree </dev/null) &&
+ REF=$(git rev-parse HEAD) &&
+ VAL=$(git commit-tree $TREE </dev/null) &&
+ git update-ref refs/heads/$REF $VAL &&
+ test $(git rev-parse $REF 2>err) = $REF &&
+ grep "refname.*${REF}.*ambiguous" err
+'
+
+test_expect_success 'ambiguous short sha1 ref' '
+ TREE=$(git mktree </dev/null) &&
+ REF=$(git rev-parse --short HEAD) &&
+ VAL=$(git commit-tree $TREE </dev/null) &&
+ git update-ref refs/heads/$REF $VAL &&
+ test $(git rev-parse $REF 2>err) = $VAL &&
+ grep "refname.*${REF}.*ambiguous" err
+'
+
test_done