net/http: simplify http.Request.Clone

By using maps.Clone and omitting nil checks when calling
http.Header.Clone.

I'm not using slices.Clone because the result of slices.Clone
may have additional unused capacity.

Change-Id: I4aed0fea218404c7270e35324e6bd62d855296c7
GitHub-Last-Rev: 9fd5dd59078c69c9a8057f6fc4a90f7c6aac893b
GitHub-Pull-Request: golang/go#69070
Reviewed-on: https://go-review.googlesource.com/c/go/+/608295
Reviewed-by: Damien Neil <dneil@google.com>
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/net/http/request.go b/src/net/http/request.go
index ad1b5a620b07ae1d6145ee1bcc7a1fc0f7158d27..686d53345aebd9393a40069dcb3aa115f04ed40a 100644 (file)
--- a/src/net/http/request.go
+++ b/src/net/http/request.go
@@ -15,6 +15,7 @@ import (
        "errors"
        "fmt"
        "io"
+       "maps"
        "mime"
        "mime/multipart"
        "net/http/httptrace"
@@ -390,12 +391,8 @@ func (r *Request) Clone(ctx context.Context) *Request {
        *r2 = *r
        r2.ctx = ctx
        r2.URL = cloneURL(r.URL)
-       if r.Header != nil {
-               r2.Header = r.Header.Clone()
-       }
-       if r.Trailer != nil {
-               r2.Trailer = r.Trailer.Clone()
-       }
+       r2.Header = r.Header.Clone()
+       r2.Trailer = r.Trailer.Clone()
        if s := r.TransferEncoding; s != nil {
                s2 := make([]string, len(s))
                copy(s2, s)
@@ -411,13 +408,7 @@ func (r *Request) Clone(ctx context.Context) *Request {
                copy(s2, s)
                r2.matches = s2
        }
-       if s := r.otherValues; s != nil {
-               s2 := make(map[string]string, len(s))
-               for k, v := range s {
-                       s2[k] = v
-               }
-               r2.otherValues = s2
-       }
+       r2.otherValues = maps.Clone(r.otherValues)
        return r2
 }