net/http: return ErrNoCookie from Request.Cookie when name is ""

Request.Cookie(name string) will return the first cookie
when cookie name is "". Since readCookies in
file net/http/cookie.go at line 247 return all cookies
when second parameter is a empty string.

To fix it, Return ErrNoCookie from Request.Cookie(""),
instead of the first cookie in the request.

Fixes #53181

Change-Id: Ie623ca4c53da64ef7623a7863292a2d771f76832
GitHub-Last-Rev: 01098cd5dbcc8d65e9c0893e0586601584e5f8b9
GitHub-Pull-Request: golang/go#53183
Reviewed-on: https://go-review.googlesource.com/c/go/+/409754
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Damien Neil <dneil@google.com>

diff --git a/src/net/http/request.go b/src/net/http/request.go
index 5439cb364661565d2a03816bd23713d8bcdadb29..a03a54b9437870e4cacf865033afd51cde277009 100644 (file)
--- a/src/net/http/request.go
+++ b/src/net/http/request.go
@@ -416,6 +416,9 @@ var ErrNoCookie = errors.New("http: named cookie not present")
 // If multiple cookies match the given name, only one cookie will
 // be returned.
 func (r *Request) Cookie(name string) (*Cookie, error) {
+       if name == "" {
+               return nil, ErrNoCookie
+       }
        for _, c := range readCookies(r.Header, name) {
                return c, nil
        }

diff --git a/src/net/http/request_test.go b/src/net/http/request_test.go
index d285840c1cec424e80a1ba45989d1c006605d75d..ce673d34a232856ae6fa6a7332312e79ef4cfb7e 100644 (file)
--- a/src/net/http/request_test.go
+++ b/src/net/http/request_test.go
@@ -1177,6 +1177,47 @@ func testMultipartFile(t *testing.T, req *Request, key, expectFilename, expectCo
        return f
 }
 
+// Issue 53181: verify Request.Cookie return the correct Cookie.
+// Return ErrNoCookie instead of the first cookie when name is "".
+func TestRequestCookie(t *testing.T) {
+       for _, tt := range []struct {
+               name        string
+               value       string
+               expectedErr error
+       }{
+               {
+                       name:        "foo",
+                       value:       "bar",
+                       expectedErr: nil,
+               },
+               {
+                       name:        "",
+                       expectedErr: ErrNoCookie,
+               },
+       } {
+               req, err := NewRequest("GET", "http://example.com/", nil)
+               if err != nil {
+                       t.Fatal(err)
+               }
+               req.AddCookie(&Cookie{Name: tt.name, Value: tt.value})
+               c, err := req.Cookie(tt.name)
+               if err != tt.expectedErr {
+                       t.Errorf("got %v, want %v", err, tt.expectedErr)
+               }
+
+               // skip if error occured.
+               if err != nil {
+                       continue
+               }
+               if c.Value != tt.value {
+                       t.Errorf("got %v, want %v", c.Value, tt.value)
+               }
+               if c.Name != tt.name {
+                       t.Errorf("got %s, want %v", tt.name, c.Name)
+               }
+       }
+}
+
 const (
        fileaContents = "This is a test file."
        filebContents = "Another test file."