net/http: use index.html modtime (not directory) for If-Modified-Since

Thanks to Håvid Falch for finding the problem.

Fixes #3414

R=r, rsc
CC=golang-dev
https://golang.org/cl/6300081

diff --git a/src/pkg/net/http/fs.go b/src/pkg/net/http/fs.go
index f35dd32c3055426cfed876f8af69ff8ea5454440..2ef27a18b4e05b32dd9448a87750a52f6d83b52d 100644 (file)
--- a/src/pkg/net/http/fs.go
+++ b/src/pkg/net/http/fs.go
@@ -243,9 +243,6 @@ func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirec
 
        // use contents of index.html for directory, if present
        if d.IsDir() {
-               if checkLastModified(w, r, d.ModTime()) {
-                       return
-               }
                index := name + indexPage
                ff, err := fs.Open(index)
                if err == nil {
@@ -259,11 +256,16 @@ func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirec
                }
        }
 
+       // Still a directory? (we didn't find an index.html file)
        if d.IsDir() {
+               if checkLastModified(w, r, d.ModTime()) {
+                       return
+               }
                dirList(w, f)
                return
        }
 
+       // serverContent will check modification time
        serveContent(w, r, d.Name(), d.ModTime(), d.Size(), f)
 }
 

diff --git a/src/pkg/net/http/fs_test.go b/src/pkg/net/http/fs_test.go
index 5aa93ce58373d7437b79363e6aa5dab2b0666467..45580cbd2ae3fd102423efaa5773d5d0c7c77012 100644 (file)
--- a/src/pkg/net/http/fs_test.go
+++ b/src/pkg/net/http/fs_test.go
@@ -16,6 +16,7 @@ import (
        "net/url"
        "os"
        "os/exec"
+       "path"
        "path/filepath"
        "regexp"
        "runtime"
@@ -325,6 +326,122 @@ func TestServeIndexHtml(t *testing.T) {
        }
 }
 
+type fakeFileInfo struct {
+       dir      bool
+       basename string
+       modtime  time.Time
+       ents     []*fakeFileInfo
+       contents string
+}
+
+func (f *fakeFileInfo) Name() string       { return f.basename }
+func (f *fakeFileInfo) Sys() interface{}   { return nil }
+func (f *fakeFileInfo) ModTime() time.Time { return f.modtime }
+func (f *fakeFileInfo) IsDir() bool        { return f.dir }
+func (f *fakeFileInfo) Size() int64        { return int64(len(f.contents)) }
+func (f *fakeFileInfo) Mode() os.FileMode {
+       if f.dir {
+               return 0755 | os.ModeDir
+       }
+       return 0644
+}
+
+type fakeFile struct {
+       io.ReadSeeker
+       fi   *fakeFileInfo
+       path string // as opened
+}
+
+func (f *fakeFile) Close() error               { return nil }
+func (f *fakeFile) Stat() (os.FileInfo, error) { return f.fi, nil }
+func (f *fakeFile) Readdir(count int) ([]os.FileInfo, error) {
+       if !f.fi.dir {
+               return nil, os.ErrInvalid
+       }
+       var fis []os.FileInfo
+       for _, fi := range f.fi.ents {
+               fis = append(fis, fi)
+       }
+       return fis, nil
+}
+
+type fakeFS map[string]*fakeFileInfo
+
+func (fs fakeFS) Open(name string) (File, error) {
+       name = path.Clean(name)
+       f, ok := fs[name]
+       if !ok {
+               println("fake filesystem didn't find file", name)
+               return nil, os.ErrNotExist
+       }
+       return &fakeFile{ReadSeeker: strings.NewReader(f.contents), fi: f, path: name}, nil
+}
+
+func TestDirectoryIfNotModified(t *testing.T) {
+       const indexContents = "I am a fake index.html file"
+       fileMod := time.Unix(1000000000, 0).UTC()
+       fileModStr := fileMod.Format(TimeFormat)
+       dirMod := time.Unix(123, 0).UTC()
+       indexFile := &fakeFileInfo{
+               basename: "index.html",
+               modtime:  fileMod,
+               contents: indexContents,
+       }
+       fs := fakeFS{
+               "/": &fakeFileInfo{
+                       dir:     true,
+                       modtime: dirMod,
+                       ents:    []*fakeFileInfo{indexFile},
+               },
+               "/index.html": indexFile,
+       }
+
+       ts := httptest.NewServer(FileServer(fs))
+       defer ts.Close()
+
+       res, err := Get(ts.URL)
+       if err != nil {
+               t.Fatal(err)
+       }
+       b, err := ioutil.ReadAll(res.Body)
+       if err != nil {
+               t.Fatal(err)
+       }
+       if string(b) != indexContents {
+               t.Fatalf("Got body %q; want %q", b, indexContents)
+       }
+       res.Body.Close()
+
+       lastMod := res.Header.Get("Last-Modified")
+       if lastMod != fileModStr {
+               t.Fatalf("initial Last-Modified = %q; want %q", lastMod, fileModStr)
+       }
+
+       req, _ := NewRequest("GET", ts.URL, nil)
+       req.Header.Set("If-Modified-Since", lastMod)
+
+       res, err = DefaultClient.Do(req)
+       if err != nil {
+               t.Fatal(err)
+       }
+       if res.StatusCode != 304 {
+               t.Fatalf("Code after If-Modified-Since request = %v; want 304", res.StatusCode)
+       }
+       res.Body.Close()
+
+       // Advance the index.html file's modtime, but not the directory's.
+       indexFile.modtime = indexFile.modtime.Add(1 * time.Hour)
+
+       res, err = DefaultClient.Do(req)
+       if err != nil {
+               t.Fatal(err)
+       }
+       if res.StatusCode != 200 {
+               t.Fatalf("Code after second If-Modified-Since request = %v; want 200; res is %#v", res.StatusCode, res)
+       }
+       res.Body.Close()
+}
+
 func TestServeContent(t *testing.T) {
        type req struct {
                name    string