Fix error message when --query and --query2 are both used on GET /groups/

--query and --query2 on GET /groups/ are mutually exclusive. Using
both of these options at the same time already failed because the
QueryGroups REST endpoint was always returned when --query2 was
specified and QueryGroups was rejecting --query with:

  "--query" is not a valid option

Change-Id: I89aa4ea8c7f5ed8e354e0cf42635b96aba7ed93e
Signed-off-by: Edwin Kempin <ekempin@google.com>

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/group/GroupsIT.java

@@ -0,0 +1,32 @@
+// Copyright (C) 2017 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License
+
+package com.google.gerrit.acceptance.rest.group;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.gerrit.acceptance.AbstractDaemonTest;
+import com.google.gerrit.acceptance.RestResponse;
+
+import org.junit.Test;
+
+public class GroupsIT extends AbstractDaemonTest {
+  @Test
+  public void invalidQueryOptions() throws Exception {
+    RestResponse r = adminRestSession.put("/groups/?query=foo&query2=bar");
+    r.assertBadRequest();
+    assertThat(r.getEntityContent())
+        .isEqualTo("\"query\" and \"query2\" options are mutually exclusive");
+  }
+}

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/restapi/NeedsParams.java

@@ -28,5 +28,5 @@ public interface NeedsParams {
    *
    * @param params the request parameter
    */
-  void setParams(Multimap<String, String> params);
+  void setParams(Multimap<String, String> params) throws RestApiException;
 }

gerrit-server/src/main/java/com/google/gerrit/server/group/GroupsCollection.java

@@ -22,6 +22,7 @@ import com.google.gerrit.common.errors.NoSuchGroupException;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.restapi.AcceptsCreate;
 import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.IdString;
 import com.google.gerrit.extensions.restapi.NeedsParams;
 import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
@@ -69,7 +70,13 @@ public class GroupsCollection implements
   }
 
   @Override
-  public void setParams(Multimap<String, String> params) {
+  public void setParams(Multimap<String, String> params)
+      throws BadRequestException {
+    if (params.containsKey("query") && params.containsKey("query2")) {
+      throw new BadRequestException(
+          "\"query\" and \"query2\" options are mutually exclusive");
+    }
+
     // The --query2 option is defined in QueryGroups
     this.hasQuery2 = params.containsKey("query2");
   }