[PATCH] tests/socket-helpers: Only fail socket protocol check if it is really necessary

[Thomas Huth <thuth@redhat.com>]

The tests/test-char test is currently always failing on my system since
socket_can_bind_connect("::1", PF_INET6) fails with EINVAL and thus
socket_check_protocol_support() is returning -1 for an error. But IPv4
is working fine. The logic in socket_check_protocol_support() seems to
be wrong here, if either IPv6 or IPv4 is working, we should not return
an error here. Thus rework the function to only return errors if both
checks failed.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 tests/socket-helpers.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/tests/socket-helpers.c b/tests/socket-helpers.c
index 19a51e887e..62a0e0f2d9 100644
--- a/tests/socket-helpers.c
+++ b/tests/socket-helpers.c
@@ -136,22 +136,17 @@ static int socket_can_bind_connect(const char *hostname, int family)
 
 int socket_check_protocol_support(bool *has_ipv4, bool *has_ipv6)
 {
-    *has_ipv4 = *has_ipv6 = false;
+    int errv4, errv6;
 
-    if (socket_can_bind_connect("127.0.0.1", PF_INET) < 0) {
-        if (errno != EADDRNOTAVAIL) {
-            return -1;
-        }
-    } else {
-        *has_ipv4 = true;
-    }
+    errv4 = socket_can_bind_connect("127.0.0.1", PF_INET);
+    *has_ipv4 = (errv4 == 0);
 
-    if (socket_can_bind_connect("::1", PF_INET6) < 0) {
-        if (errno != EADDRNOTAVAIL) {
-            return -1;
-        }
-    } else {
-        *has_ipv6 = true;
+    errv6 = socket_can_bind_connect("::1", PF_INET6);
+    *has_ipv6 = (errv6 == 0);
+
+    if (!*has_ipv4 && !*has_ipv6 &&
+        (errv4 != EADDRNOTAVAIL || errv6 != EADDRNOTAVAIL)) {
+        return -1;
     }
 
     return 0;
-- 
2.18.2