fix(storage): deduplicate x-goog-api-client header in setHeadersFromCtx and adjust emulator read stall test parameters

Author: raj-prince

storage/client_test.go

@@ -3295,7 +3295,7 @@ func TestRetryReadStallEmulated(t *testing.T) {
 	client, err := NewClient(ctx, experimental.WithReadStallTimeout(
 		&experimental.ReadStallTimeoutConfig{
 			TargetPercentile: 0.99,
-			Min:              10 * time.Millisecond,
+			Min:              250 * time.Millisecond,
 		}))
 	if err != nil {
 		t.Fatalf("storage.NewClient: %v", err)
@@ -3361,7 +3361,7 @@ func TestGRPCRetryReadStallEmulated(t *testing.T) {
 				experimental.WithReadStallTimeout(
 					&experimental.ReadStallTimeoutConfig{
 						TargetPercentile: 0.99,
-						Min:              10 * time.Millisecond,
+						Min:              250 * time.Millisecond,
 					}),
 			}
 			if tt.bidiReads {

storage/http_client.go

@@ -1736,14 +1736,18 @@ func setHeadersFromCtx(ctx context.Context, header http.Header) {
 		// Merge x-goog-api-client values into a single space-separated value.
 		if strings.EqualFold(k, xGoogHeaderKey) {
 			alreadySetValues := header.Values(xGoogHeaderKey)
-			vals = append(vals, alreadySetValues...)
-
-			if len(vals) > 0 {
-				xGoogHeader := vals[0]
-				for _, v := range vals[1:] {
-					xGoogHeader = strings.Join([]string{xGoogHeader, v}, " ")
+			var uniqueVals []string
+			seenVals := make(map[string]bool)
+			for _, v := range append(vals, alreadySetValues...) {
+				for _, part := range strings.Split(v, " ") {
+					if part != "" && !seenVals[part] {
+						seenVals[part] = true
+						uniqueVals = append(uniqueVals, part)
+					}
 				}
-				header.Set(k, xGoogHeader)
+			}
+			if len(uniqueVals) > 0 {
+				header.Set(k, strings.Join(uniqueVals, " "))
 			}
 		} else {
 			for _, v := range vals {