net/http: skip redirecting in ServeMux when URL path for CONNECT is empty

In 1.21 ServeMux, we had a special-case to skip redirection when a given
path is empty for CONNECT requests:
https://go.googlesource.com/go/+/refs/tags/go1.24.4/src/net/http/servemux121.go#205.

This special case seems to not have been carried over to 1.22 ServeMux.
This causes needless redirection, which this CL fixes.

Fixes #74422

Change-Id: I3cc5b4d195ab0591a9139225b632cbe17f4290db
Reviewed-on: https://go-review.googlesource.com/c/go/+/699915
Reviewed-by: Sean Liao <sean@liao.dev>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: Damien Neil <dneil@google.com>

diff --git a/src/net/http/server.go b/src/net/http/server.go
index cf0bd0a91d762463f7b2a54a666ed1ba0020dc5a..6fdcd51c0a677723145b46ce5d62eda0346e5960 100644 (file)
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -2759,9 +2759,12 @@ func (mux *ServeMux) matchOrRedirect(host, method, path string, u *url.URL) (_ *
        defer mux.mu.RUnlock()
 
        n, matches := mux.tree.match(host, method, path)
-       // If we have an exact match, or we were asked not to try trailing-slash redirection,
-       // or the URL already has a trailing slash, then we're done.
-       if !exactMatch(n, path) && u != nil && !strings.HasSuffix(path, "/") {
+       // We can terminate here if any of the following is true:
+       // - We have an exact match already.
+       // - We were asked not to try trailing slash redirection.
+       // - The URL already has a trailing slash.
+       // - The URL is an empty string.
+       if !exactMatch(n, path) && u != nil && !strings.HasSuffix(path, "/") && path != "" {
                // If there is an exact match with a trailing slash, then redirect.
                path += "/"
                n2, _ := mux.tree.match(host, method, path)

diff --git a/src/net/http/server_test.go b/src/net/http/server_test.go
index f4aafc853bd5d6647d320da600de1f6c2c8522ad..832f9688b63d9c6007272a864a065fda8ffa8448 100644 (file)
--- a/src/net/http/server_test.go
+++ b/src/net/http/server_test.go
@@ -97,6 +97,7 @@ func TestFindHandler(t *testing.T) {
                {"GET", "/foo/x", "&http.handler{i:2}"},
                {"GET", "/bar/x", "&http.handler{i:4}"},
                {"GET", "/bar", `&http.redirectHandler{url:"/bar/", code:301}`},
+               {"CONNECT", "", "(http.HandlerFunc)(.*)"},
                {"CONNECT", "/", "&http.handler{i:1}"},
                {"CONNECT", "//", "&http.handler{i:1}"},
                {"CONNECT", "//foo", "&http.handler{i:5}"},
@@ -112,7 +113,7 @@ func TestFindHandler(t *testing.T) {
                r.URL = &url.URL{Path: test.path}
                gotH, _, _, _ := mux.findHandler(&r)
                got := fmt.Sprintf("%#v", gotH)
-               if got != test.wantHandler {
+               if !regexp.MustCompile(test.wantHandler).MatchString(got) {
                        t.Errorf("%s %q: got %q, want %q", test.method, test.path, got, test.wantHandler)
                }
        }