fix versionId null check in getPresignedObjectUrl properly (#1693)

Author: Paw565pl

api/src/main/java/io/minio/MinioAsyncClient.java

@@ -890,7 +890,7 @@ public String getPresignedObjectUrl(GetPresignedObjectUrlArgs args) throws Minio
     }
 
     Http.QueryParameters queryParams = new Http.QueryParameters();
-    if (args.versionId() == null) queryParams.put("versionId", args.versionId());
+    if (args.versionId() != null) queryParams.put("versionId", args.versionId());
 
     Credentials credentials = provider == null ? null : provider.fetch();
     if (credentials != null && credentials.sessionToken() != null) {

functional/TestMinioClient.java

@@ -126,6 +126,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 import okhttp3.Headers;
+import okhttp3.HttpUrl;
 import okhttp3.MultipartBody;
 import okhttp3.Request;
 import okhttp3.RequestBody;
@@ -1270,6 +1271,23 @@ public void testGetPresignedObjectUrlForGet() throws Exception {
                 .build(),
             expectedChecksum);
 
+        testTags = "[GET, versionId]";
+        String versionId = "dummy-version";
+        String urlString =
+            client.getPresignedObjectUrl(
+                GetPresignedObjectUrlArgs.builder()
+                    .method(Http.Method.GET)
+                    .bucket(bucketName)
+                    .object(objectName)
+                    .versionId(versionId)
+                    .build());
+        HttpUrl url = HttpUrl.parse(urlString);
+        Assertions.assertNotNull(url, "generated url is not valid");
+        Assertions.assertEquals(
+            versionId,
+            url.queryParameter("versionId"),
+            "versionId query param does not match the expected value");
+
         testTags = "[GET, expiry, query params]";
         Map<String, String> queryParams = new HashMap<>();
         queryParams.put("response-content-type", "application/json");