Add explanation of dummy approvals to ApprovalsUtil
Change-Id: I16643ecc1a647c2f83748ea5e47e35eb6fad80d5
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java
index b87cce3..f33a07b 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java
@@ -34,6 +34,16 @@
import java.util.List;
import java.util.Set;
+/**
+ * Utility functions to manipulate patchset approvals.
+ * <p>
+ * Approvals are overloaded, they represent both approvals and reviewers
+ * which should be CCed on a change. To ensure that reviewers are not lost
+ * there must always be an approval on each patchset for each reviewer,
+ * even if the reviewer hasn't actually given a score to the change. To
+ * mark the "no score" case, a dummy approval, which may live in any of
+ * the available categories, with a score of 0 is used.
+ */
public class ApprovalsUtil {
private final ReviewDb db;
private final ApprovalTypes approvalTypes;
