test_cmp expect actual
'
+# b---bc
+# / \ /
+# a X
+# \ / \
+# c---cb
+test_expect_success 'setup criss-cross' '
+ mkdir criss-cross &&
+ (cd criss-cross &&
+ git init &&
+ test_commit A &&
+ git checkout -b b master &&
+ test_commit B &&
+ git checkout -b c master &&
+ test_commit C &&
+ git checkout -b bc b -- &&
+ git merge c &&
+ git checkout -b cb c -- &&
+ git merge b &&
+ 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 cb..bc > actual &&
+ test -z "$(cat actual)")
+'
+
+# no commits in repository descend from cb
+test_expect_failure 'criss-cross: rev-list --ancestry-path --all ^cb' '
+ (cd criss-cross &&
+ git rev-list --ancestry-path --all ^cb > actual &&
+ test -z "$(cat actual)")
+'
+
test_done