test_cmp expect actual
'
+# b---bc
+# / \ /
+# a X
+# \ / \
+# c---cb
+#
+# All refnames prefixed with 'x' to avoid confusion with the tags
+# generated by test_commit on case-insensitive systems.
+test_expect_success 'setup criss-cross' '
+ mkdir criss-cross &&
+ (cd criss-cross &&
+ git init &&
+ test_commit A &&
+ git checkout -b xb master &&
+ test_commit B &&
+ git checkout -b xc master &&
+ test_commit C &&
+ git checkout -b xbc xb -- &&
+ git merge xc &&
+ git checkout -b xcb xc -- &&
+ git merge xb &&
+ git checkout master)
+'
+
+# no commits in bc descend from cb
+test_expect_success 'criss-cross: rev-list --ancestry-path cb..bc' '
+ (cd criss-cross &&
+ git rev-list --ancestry-path xcb..xbc > actual &&
+ test -z "$(cat actual)")
+'
+
+# no commits in repository descend from cb
+test_expect_success 'criss-cross: rev-list --ancestry-path --all ^cb' '
+ (cd criss-cross &&
+ git rev-list --ancestry-path --all ^xcb > actual &&
+ test -z "$(cat actual)")
+'
+
test_done