Fix suggest reviewers when requested without limit option

According to documentation default limit is used when limit is not
passed (rest-api-changes.txt):
"If result limit is not passed, then the default 10 is used."

Without this change, limit field got not initialized properly when
in an empty result in any case.

Change-Id: I2fddcd589cb9c39d73499e6eaa927cacd21d33d7

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/SuggestReviewersIT.java

@@ -191,6 +191,21 @@ public class SuggestReviewersIT extends AbstractDaemonTest {
     assertEquals(2, reviewers.size());
   }
 
+  @Test
+  public void suggestReviewersWithoutLimitOptionSpecified() throws Exception {
+    String changeId = createChange().getChangeId();
+    String query = "users3";
+    List<SuggestedReviewerInfo> suggestedReviewerInfos = newGson().fromJson(
+        adminSession.get("/changes/"
+            + changeId
+            + "/suggest_reviewers?q="
+            + query)
+            .getReader(),
+        new TypeToken<List<SuggestedReviewerInfo>>() {}
+        .getType());
+    assertEquals(1, suggestedReviewerInfos.size());
+  }
+
   private List<SuggestedReviewerInfo> suggestReviewers(RestSession session,
       String changeId, String query, int n) throws IOException {
     return newGson().fromJson(

gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestReviewers.java

@@ -115,6 +115,7 @@ public class SuggestReviewers implements RestReadView<ChangeResource> {
     this.reviewerSuggestionCache = reviewerSuggestionCache;
     this.maxSuggestedReviewers =
         cfg.getInt("suggest", "maxSuggestedReviewers", DEFAULT_MAX_SUGGESTED);
+    this.limit = this.maxSuggestedReviewers;
     this.fullTextMaxMatches =
         cfg.getInt("suggest", "fullTextSearchMaxMatches",
             DEFAULT_MAX_MATCHES);