This was revealed when I made a cut-paste mistake in an upgrade to virSocketAddrGetRange(), leading to failure to check for the end address being outside of the defined network, but a negative test case that should have caught the error instead returned success. The problem was that testRange in sockettest.c was written so that when it expected a failure, even an "unexpected success" would be considered as an "expected failure" because of the way the check in testRange was done. testRange had this: if (gotsize < 0 || gotsize != size) { return pass ? -1 : 0; } else { return pass ? 0 : -1; } but all the tests that expected a failure give "-1" as the expected size. So in a case where we expect a failure, we would have pass == false and size == -1. If virSocketAddrGetRange() was incorrectly *successful* (returned some positive number), then "gotsize != size" would be, e.g. "276 != -1", so we would take the if clause and, since pass == false, we would return 0 (success i.e. expected failure). The solution is that in the case where we expect failure, we should just ignore size - virSocketAddrGetRange() must return -1 in order for us to report "expected failure == success". --- Here's the email where jferlan points out the typo and asks about the apparent lack of a proper negative test case: https://www.redhat.com/archives/libvir-list/2015-May/msg01166.html tests/sockettest.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/tests/sockettest.c b/tests/sockettest.c index 84170d5..292edb6 100644 --- a/tests/sockettest.c +++ b/tests/sockettest.c @@ -103,10 +103,12 @@ testRange(const char *saddrstr, const char *eaddrstr, int gotsize = virSocketAddrGetRange(&saddr, &eaddr, &netaddr, prefix); VIR_DEBUG("Size want %d vs got %d", size, gotsize); - if (gotsize < 0 || gotsize != size) { - return pass ? -1 : 0; + if (pass) { + /* fail if virSocketAddrGetRange returns failure, or unexpected size */ + return (gotsize < 0 || gotsize != size) ? -1 : 0; } else { - return pass ? 0 : -1; + /* succeed if virSocketAddrGetRange fails, otherwise fail. */ + return gotsize < 0 ? 0 : -1; } } -- 2.1.0