Fix API link header

modules/context/api.go

@@ -7,6 +7,7 @@ package context
 
 import (
 	"fmt"
+	"net/url"
 	"strings"
 
 	"github.com/go-macaron/csrf"
@@ -77,23 +78,49 @@ func (ctx *APIContext) Error(status int, title string, obj interface{}) {
 	})
 }
 
-// SetLinkHeader sets pagination link header by given total number and page size.
-func (ctx *APIContext) SetLinkHeader(total, pageSize int) {
-	page := NewPagination(total, pageSize, ctx.QueryInt("page"), 0)
+func genAPILinks(curURL *url.URL, total, pageSize, curPage int) []string {
+	page := NewPagination(total, pageSize, curPage, 0)
 	paginater := page.Paginater
 	links := make([]string, 0, 4)
+
 	if paginater.HasNext() {
-		links = append(links, fmt.Sprintf("<%s%s?page=%d>; rel=\"next\"", setting.AppURL, ctx.Req.URL.Path[1:], paginater.Next()))
+		u := *curURL
+		queries := u.Query()
+		queries.Set("page", fmt.Sprintf("%d", paginater.Next()))
+		u.RawQuery = queries.Encode()
+
+		links = append(links, fmt.Sprintf("<%s%s>; rel=\"next\"", setting.AppURL, u.RequestURI()[1:]))
 	}
 	if !paginater.IsLast() {
-		links = append(links, fmt.Sprintf("<%s%s?page=%d>; rel=\"last\"", setting.AppURL, ctx.Req.URL.Path[1:], paginater.TotalPages()))
+		u := *curURL
+		queries := u.Query()
+		queries.Set("page", fmt.Sprintf("%d", paginater.TotalPages()))
+		u.RawQuery = queries.Encode()
+
+		links = append(links, fmt.Sprintf("<%s%s>; rel=\"last\"", setting.AppURL, u.RequestURI()[1:]))
 	}
 	if !paginater.IsFirst() {
-		links = append(links, fmt.Sprintf("<%s%s?page=1>; rel=\"first\"", setting.AppURL, ctx.Req.URL.Path[1:]))
+		u := *curURL
+		queries := u.Query()
+		queries.Set("page", "1")
+		u.RawQuery = queries.Encode()
+
+		links = append(links, fmt.Sprintf("<%s%s>; rel=\"first\"", setting.AppURL, u.RequestURI()[1:]))
 	}
 	if paginater.HasPrevious() {
-		links = append(links, fmt.Sprintf("<%s%s?page=%d>; rel=\"prev\"", setting.AppURL, ctx.Req.URL.Path[1:], paginater.Previous()))
+		u := *curURL
+		queries := u.Query()
+		queries.Set("page", fmt.Sprintf("%d", paginater.Previous()))
+		u.RawQuery = queries.Encode()
+
+		links = append(links, fmt.Sprintf("<%s%s>; rel=\"prev\"", setting.AppURL, u.RequestURI()[1:]))
 	}
+	return links
+}
+
+// SetLinkHeader sets pagination link header by given total number and page size.
+func (ctx *APIContext) SetLinkHeader(total, pageSize int) {
+	links := genAPILinks(ctx.Req.URL, total, pageSize, ctx.QueryInt("page"))
 
 	if len(links) > 0 {
 		ctx.Header().Set("Link", strings.Join(links, ","))

modules/context/api_test.go

@@ -0,0 +1,51 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package context
+
+import (
+	"net/url"
+	"strconv"
+	"testing"
+
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGenAPILinks(t *testing.T) {
+	setting.AppURL = "http://localhost:3000/"
+	var kases = map[string][]string{
+		"api/v1/repos/jerrykan/example-repo/issues?state=all": {
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=2&state=all>; rel="next"`,
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=5&state=all>; rel="last"`,
+		},
+		"api/v1/repos/jerrykan/example-repo/issues?state=all&page=1": {
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=2&state=all>; rel="next"`,
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=5&state=all>; rel="last"`,
+		},
+		"api/v1/repos/jerrykan/example-repo/issues?state=all&page=2": {
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=3&state=all>; rel="next"`,
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=5&state=all>; rel="last"`,
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=1&state=all>; rel="first"`,
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=1&state=all>; rel="prev"`,
+		},
+		"api/v1/repos/jerrykan/example-repo/issues?state=all&page=5": {
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=1&state=all>; rel="first"`,
+			`<http://localhost:3000/api/v1/repos/jerrykan/example-repo/issues?page=4&state=all>; rel="prev"`,
+		},
+	}
+
+	for req, response := range kases {
+		u, err := url.Parse(setting.AppURL + req)
+		assert.NoError(t, err)
+
+		p := u.Query().Get("page")
+		curPage, _ := strconv.Atoi(p)
+
+		links := genAPILinks(u, 100, 20, curPage)
+
+		assert.EqualValues(t, links, response)
+	}
+}