Avoid setting multiple values for certain headers

internal/git/archive.go

@@ -138,14 +138,14 @@ func (a *archive) Inject(w http.ResponseWriter, r *http.Request, sendData string
 
 func setArchiveHeaders(w http.ResponseWriter, format string, archiveFilename string) {
 	w.Header().Del("Content-Length")
-	w.Header().Add("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, archiveFilename))
+	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, archiveFilename))
 	if format == "zip" {
-		w.Header().Add("Content-Type", "application/zip")
+		w.Header().Set("Content-Type", "application/zip")
 	} else {
-		w.Header().Add("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Type", "application/octet-stream")
 	}
-	w.Header().Add("Content-Transfer-Encoding", "binary")
-	w.Header().Add("Cache-Control", "private")
+	w.Header().Set("Content-Transfer-Encoding", "binary")
+	w.Header().Set("Cache-Control", "private")
 }
 
 func parseArchiveFormat(format string) (*exec.Cmd, string) {

internal/git/archive_test.go

@@ -2,7 +2,10 @@ package git
 
 import (
 	"io/ioutil"
+	"net/http/httptest"
 	"testing"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/testhelper"
 )
 
 func TestParseBasename(t *testing.T) {
@@ -42,3 +45,27 @@ func TestFinalizeArchive(t *testing.T) {
 		t.Fatalf("expected nil from finalizeCachedArchive, received %v", err)
 	}
 }
+
+func TestSetArchiveHeaders(t *testing.T) {
+	for _, testCase := range []struct{ in, out string }{
+		{"zip", "application/zip"},
+		{"zippy", "application/octet-stream"},
+		{"rezip", "application/octet-stream"},
+		{"_anything_", "application/octet-stream"},
+	} {
+		w := httptest.NewRecorder()
+
+		// These should be replaced, not appended to
+		w.Header().Set("Content-Type", "test")
+		w.Header().Set("Content-Length", "test")
+		w.Header().Set("Content-Disposition", "test")
+		w.Header().Set("Cache-Control", "test")
+
+		setArchiveHeaders(w, testCase.in, "filename")
+
+		testhelper.AssertResponseHeader(t, w, "Content-Type", testCase.out)
+		testhelper.AssertResponseHeader(t, w, "Content-Length")
+		testhelper.AssertResponseHeader(t, w, "Content-Disposition", `attachment; filename="filename"`)
+		testhelper.AssertResponseHeader(t, w, "Cache-Control", "private")
+	}
+}

internal/git/git-http.go

@@ -77,8 +77,8 @@ func handleGetInfoRefs(w http.ResponseWriter, r *http.Request, a *api.Response)
 	defer helper.CleanUpProcessGroup(cmd) // Ensure brute force subprocess clean-up
 
 	// Start writing the response
-	w.Header().Add("Content-Type", fmt.Sprintf("application/x-%s-advertisement", rpc))
-	w.Header().Add("Cache-Control", "no-cache")
+	w.Header().Set("Content-Type", fmt.Sprintf("application/x-%s-advertisement", rpc))
+	w.Header().Set("Cache-Control", "no-cache")
 	w.WriteHeader(200) // Don't bother with HTTP 500 from this point on, just return
 	if err := pktLine(w, fmt.Sprintf("# service=%s\n", rpc)); err != nil {
 		helper.LogError(r, fmt.Errorf("handleGetInfoRefs: pktLine: %v", err))
@@ -164,8 +164,8 @@ func handlePostRPC(w http.ResponseWriter, r *http.Request, a *api.Response) {
 	r.Body.Close()
 
 	// Start writing the response
-	w.Header().Add("Content-Type", fmt.Sprintf("application/x-%s-result", action))
-	w.Header().Add("Cache-Control", "no-cache")
+	w.Header().Set("Content-Type", fmt.Sprintf("application/x-%s-result", action))
+	w.Header().Set("Cache-Control", "no-cache")
 	w.WriteHeader(200) // Don't bother with HTTP 500 from this point on, just return
 
 	// This io.Copy may take a long time, both for Git push and pull.

internal/staticpages/servefile_test.go

@@ -116,7 +116,7 @@ func testServingThePregzippedFile(t *testing.T, enableGzip bool) {
 		}
 	} else {
 		testhelper.AssertResponseCode(t, w, 200)
-		testhelper.AssertResponseHeader(t, w, "Content-Encoding", "")
+		testhelper.AssertResponseHeader(t, w, "Content-Encoding")
 		if w.Body.String() != fileContent {
 			t.Error("We should serve the file: ", w.Body.String())
 		}

internal/testhelper/testhelper.go

@@ -63,9 +63,17 @@ func AssertResponseBody(t *testing.T, response *httptest.ResponseRecorder, expec
 	}
 }
 
-func AssertResponseHeader(t *testing.T, response *httptest.ResponseRecorder, header string, expectedValue string) {
-	if response.Header().Get(header) != expectedValue {
-		t.Fatalf("for HTTP request expected to receive the header %q with %q, got %q", header, expectedValue, response.Header().Get(header))
+func AssertResponseHeader(t *testing.T, w http.ResponseWriter, header string, expected ...string) {
+	actual := w.Header()[http.CanonicalHeaderKey(header)]
+
+	if len(expected) != len(actual) {
+		t.Fatalf("for HTTP request expected to receive the header %q with %+v, got %+v", header, expected, actual)
+	}
+
+	for i, value := range expected {
+		if value != actual[i] {
+			t.Fatalf("for HTTP request expected to receive the header %q with %+v, got %+v", header, expected, actual)
+		}
 	}
 }