net/url: fix missing handling for opaque value in ResolveReference method

The current implementation doesn't resolve as per spec RFC 3986 the case
where the base URL has an opaque value, and the reference doesn't have
either a scheme, authority or path. Currently, this specific case falls
back to the "abs_path" or "rel_path" cases, where the final path results
of the base_path being resolved relatively to the reference's, but since
the opaque value is stored independently, it needs a case of its own.

The algorith for resolving references is defined in RFC 3986 section 5.2.2:
https://www.rfc-editor.org/rfc/rfc3986.html#section-5.2.2

Fixes #66084

Change-Id: I82813e2333d8f2c4433c742f10e8c941888b55ac
GitHub-Last-Rev: cb96626988f4bd4546ee840ba50e2b4efa1e23f1
GitHub-Pull-Request: golang/go#66415
Reviewed-on: https://go-review.googlesource.com/c/go/+/572915
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>

diff --git a/src/net/url/url.go b/src/net/url/url.go
index 7cd6913ad7e3f794cff301ae1ca709c335023add..6c74f3fbf98a424a940656d69da20d08ad14db07 100644 (file)
--- a/src/net/url/url.go
+++ b/src/net/url/url.go
@@ -1124,6 +1124,13 @@ func (u *URL) ResolveReference(ref *URL) *URL {
                        url.RawFragment = u.RawFragment
                }
        }
+       if ref.Path == "" && u.Opaque != "" {
+               url.Opaque = u.Opaque
+               url.User = nil
+               url.Host = ""
+               url.Path = ""
+               return &url
+       }
        // The "abs_path" or "rel_path" cases.
        url.Host = u.Host
        url.User = u.User

diff --git a/src/net/url/url_test.go b/src/net/url/url_test.go
index 4aa20bb95feb0bdf2cb5cba2f3e7330e55588e89..68219c3df1081d6aa792cbb86ef5999a21e8edc8 100644 (file)
--- a/src/net/url/url_test.go
+++ b/src/net/url/url_test.go
@@ -1248,6 +1248,14 @@ var resolveReferenceTests = []struct {
 
        // Empty path and query but with ForceQuery (issue 46033).
        {"https://a/b/c/d;p?q#s", "?", "https://a/b/c/d;p?"},
+
+       // Opaque URLs (issue 66084).
+       {"https://foo.com/bar?a=b", "http:opaque", "http:opaque"},
+       {"http:opaque?x=y#zzz", "https:/foo?a=b#frag", "https:/foo?a=b#frag"},
+       {"http:opaque?x=y#zzz", "https:foo:bar", "https:foo:bar"},
+       {"http:opaque?x=y#zzz", "https:bar/baz?a=b#frag", "https:bar/baz?a=b#frag"},
+       {"http:opaque?x=y#zzz", "https://user@host:1234?a=b#frag", "https://user@host:1234?a=b#frag"},
+       {"http:opaque?x=y#zzz", "?a=b#frag", "http:opaque?a=b#frag"},
 }
 
 func TestResolveReference(t *testing.T) {