http.go: Request.SetURI() (Fix #1141)

http.go

@@ -774,6 +774,20 @@ func (req *Request) URI() *URI {
 	return &req.uri
 }
 
+// SetURI initializes request URI
+// Use this method if a single URI may be reused across multiple requests.
+// Otherwise, you can just use SetRequestURI() and it will be parsed as new URI.
+// The URI is copied and can be safely modified later.
+func (req *Request) SetURI(newUri *URI) {
+	if newUri != nil {
+		newUri.CopyTo(&req.uri)
+		req.parsedURI = true
+		return
+	}
+	req.uri.Reset()
+	req.parsedURI = false
+}
+
 func (req *Request) parseURI() error {
 	if req.parsedURI {
 		return nil

http_test.go

@@ -515,6 +515,31 @@ tailfoobar`
 	}
 }
 
+func TestRequestSetURI(t *testing.T) {
+	t.Parallel()
+
+	var r Request
+
+	uri := "/foo/bar?baz"
+	u := &URI{}
+	u.Parse(nil, []byte(uri)) //nolint:errcheck
+	// Set request uri via SetURI()
+	r.SetURI(u) // copies URI
+	// modifying an original URI struct doesn't affect stored URI inside of request
+	u.SetPath("newPath")
+	if string(r.RequestURI()) != uri {
+		t.Fatalf("unexpected request uri %q. Expecting %q", r.RequestURI(), uri)
+	}
+
+	// Set request uri to nil just resets the URI
+	r.Reset()
+	uri = "/"
+	r.SetURI(nil)
+	if string(r.RequestURI()) != uri {
+		t.Fatalf("unexpected request uri %q. Expecting %q", r.RequestURI(), uri)
+	}
+}
+
 func TestRequestRequestURI(t *testing.T) {
 	t.Parallel()