Allow redirect URI path to not be normalized. (#1638)

* Allow redirect URI path to not be normalized.

* Introduce DisableRedirectPathNormalizing field to Request

* Use field name as start of comment.

Co-authored-by: Erik Dubbelboer <erik@dubbelboer.com>

---------

Co-authored-by: Erik Dubbelboer <erik@dubbelboer.com>

client.go

@@ -1064,16 +1064,17 @@ func doRequestFollowRedirects(req *Request, resp *Response, url string, maxRedir
 			err = ErrMissingLocation
 			break
 		}
-		url = getRedirectURL(url, location)
+		url = getRedirectURL(url, location, req.DisableRedirectPathNormalizing)
 	}
 
 	return statusCode, body, err
 }
 
-func getRedirectURL(baseURL string, location []byte) string {
+func getRedirectURL(baseURL string, location []byte, disablePathNormalizing bool) string {
 	u := AcquireURI()
 	u.Update(baseURL)
 	u.UpdateBytes(location)
+	u.DisablePathNormalizing = disablePathNormalizing
 	redirectURL := u.String()
 	ReleaseURI(u)
 	return redirectURL

client_test.go

@@ -1589,6 +1589,10 @@ func TestClientFollowRedirects(t *testing.T) {
 				u := ctx.URI()
 				u.Update("/bar")
 				ctx.Redirect(u.String(), StatusFound)
+			case "/abc/*/123":
+				u := ctx.URI()
+				u.Update("/xyz/*/456")
+				ctx.Redirect(u.String(), StatusFound)
 			default:
 				ctx.Success("text/plain", ctx.Path())
 			}
@@ -1710,6 +1714,31 @@ func TestClientFollowRedirects(t *testing.T) {
 		ReleaseResponse(resp)
 	}
 
+	for i := 0; i < 10; i++ {
+		req := AcquireRequest()
+		resp := AcquireResponse()
+
+		req.SetRequestURI("http://xxx/abc/*/123")
+		req.URI().DisablePathNormalizing = true
+		req.DisableRedirectPathNormalizing = true
+
+		err := c.DoRedirects(req, resp, 16)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		if statusCode := resp.StatusCode(); statusCode != StatusOK {
+			t.Fatalf("unexpected status code: %d", statusCode)
+		}
+
+		if body := string(resp.Body()); body != "/xyz/*/456" {
+			t.Fatalf("unexpected response %q. Expecting %q", body, "/xyz/*/456")
+		}
+
+		ReleaseRequest(req)
+		ReleaseResponse(resp)
+	}
+
 	req := AcquireRequest()
 	resp := AcquireResponse()
 
@@ -3306,3 +3335,60 @@ func TestClientTransportEx(t *testing.T) {
 		t.Errorf("round trip count should be: %v", roundTripCount)
 	}
 }
+
+func Test_getRedirectURL(t *testing.T) {
+	type args struct {
+		baseURL                string
+		location               []byte
+		disablePathNormalizing bool
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "Path normalizing enabled, no special characters in path",
+			args: args{
+				baseURL:                "http://foo.example.com/abc",
+				location:               []byte("http://bar.example.com/def"),
+				disablePathNormalizing: false,
+			},
+			want: "http://bar.example.com/def",
+		},
+		{
+			name: "Path normalizing enabled, special characters in path",
+			args: args{
+				baseURL:                "http://foo.example.com/abc/*/def",
+				location:               []byte("http://bar.example.com/123/*/456"),
+				disablePathNormalizing: false,
+			},
+			want: "http://bar.example.com/123/%2A/456",
+		},
+		{
+			name: "Path normalizing disabled, no special characters in path",
+			args: args{
+				baseURL:                "http://foo.example.com/abc",
+				location:               []byte("http://bar.example.com/def"),
+				disablePathNormalizing: true,
+			},
+			want: "http://bar.example.com/def",
+		},
+		{
+			name: "Path normalizing disabled, special characters in path",
+			args: args{
+				baseURL:                "http://foo.example.com/abc/*/def",
+				location:               []byte("http://bar.example.com/123/*/456"),
+				disablePathNormalizing: true,
+			},
+			want: "http://bar.example.com/123/*/456",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := getRedirectURL(tt.args.baseURL, tt.args.location, tt.args.disablePathNormalizing); got != tt.want {
+				t.Errorf("getRedirectURL() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

http.go

@@ -71,6 +71,12 @@ type Request struct {
 
 	// Use Host header (request.Header.SetHost) instead of the host from SetRequestURI, SetHost, or URI().SetHost
 	UseHostHeader bool
+
+	// DisableRedirectPathNormalizing disables redirect path normalization when used with DoRedirects.
+	//
+	// By default redirect path values are normalized, i.e.
+	// extra slashes are removed, special characters are encoded.
+	DisableRedirectPathNormalizing bool
 }
 
 // Response represents HTTP response.
@@ -1080,6 +1086,7 @@ func (req *Request) Reset() {
 	req.resetSkipHeader()
 	req.timeout = 0
 	req.UseHostHeader = false
+	req.DisableRedirectPathNormalizing = false
 }
 
 func (req *Request) resetSkipHeader() {