net/netip: add test that Compare and reflect.DeepEqual match

Updates #68113

Change-Id: I1107686ef364f77f48f55534ea8ec68d1785e1e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/594375
Auto-Submit: Brad Fitzpatrick <bradfitz@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

diff --git a/src/net/netip/netip_test.go b/src/net/netip/netip_test.go
index 94c70f2290ea4f5fe35cd533383dea56820378fb..e1a0a83f64511d97fc8681e024732bd032fd2abf 100644 (file)
--- a/src/net/netip/netip_test.go
+++ b/src/net/netip/netip_test.go
@@ -893,6 +893,15 @@ func TestAddrLessCompare(t *testing.T) {
                {mustIP("::1%a"), mustIP("::1%b"), true},
                {mustIP("::1%a"), mustIP("::1%a"), false},
                {mustIP("::1%b"), mustIP("::1%a"), false},
+
+               // For Issue 68113, verify that an IPv4 address and a
+               // v4-mapped-IPv6 address differing only in their zone
+               // pointer are unequal via all three of
+               // ==/Compare/reflect.DeepEqual. In Go 1.22 and
+               // earlier, these were accidentally equal via
+               // DeepEqual due to their zone pointers (z) differing
+               // but pointing to identical structures.
+               {mustIP("::ffff:11.1.1.12"), mustIP("11.1.1.12"), false},
        }
        for _, tt := range tests {
                got := tt.a.Less(tt.b)
@@ -920,6 +929,12 @@ func TestAddrLessCompare(t *testing.T) {
                                t.Errorf("Less(%q, %q) was correctly %v, but so was Less(%q, %q)", tt.a, tt.b, got, tt.b, tt.a)
                        }
                }
+
+               // Also check reflect.DeepEqual. See issue 68113.
+               deepEq := reflect.DeepEqual(tt.a, tt.b)
+               if (cmp == 0) != deepEq {
+                       t.Errorf("%q and %q differ in == (%v) vs reflect.DeepEqual (%v)", tt.a, tt.b, cmp == 0, deepEq)
+               }
        }
 
        // And just sort.