GetRelated: Add some debug logs

This makes investigation of issues with this REST endpoint easier.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: Ib165e7c8e188f6f218d70310b840b112978e66d7

java/com/google/gerrit/server/restapi/change/GetRelated.java

diff --git a/java/com/google/gerrit/server/restapi/change/GetRelated.java b/java/com/google/gerrit/server/restapi/change/GetRelated.java
index 5f075f6..6eff9b0 100644
--- a/java/com/google/gerrit/server/restapi/change/GetRelated.java
+++ b/java/com/google/gerrit/server/restapi/change/GetRelated.java
@@ -19,6 +19,7 @@
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.PatchSet;
@@ -52,6 +53,8 @@
 
 @Singleton
 public class GetRelated implements RestReadView<RevisionResource> {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   private final Provider<InternalChangeQuery> queryProvider;
   private final PatchSetUtil psUtil;
   private final RelatedChangesSorter sorter;
@@ -84,6 +87,7 @@
   private List<RelatedChangeAndCommitInfo> getRelated(RevisionResource rsrc)
       throws IOException, PermissionBackendException {
     Set<String> groups = getAllGroups(rsrc.getNotes(), psUtil);
+    logger.atFine().log("groups = %s", groups);
     if (groups.isEmpty()) {
       return Collections.emptyList();
     }
@@ -101,6 +105,7 @@
 
     boolean isEdit = rsrc.getEdit().isPresent();
     PatchSet basePs = isEdit ? rsrc.getEdit().get().getBasePatchSet() : rsrc.getPatchSet();
+    logger.atFine().log("isEdit = %s, basePs = %s", isEdit, basePs);
 
     cds = reloadChangeIfStale(cds, rsrc.getChange(), basePs);
 
@@ -111,6 +116,9 @@
         // Replace base of an edit with the edit itself.
         ps = rsrc.getPatchSet();
         commit = rsrc.getEdit().get().getEditCommit();
+        logger.atFine().log(
+            "Replaced base of edit (patch set %s, commit %s) with edit (patch set %s, commit %s)",
+            d.patchSet().id(), d.commit(), ps.id(), commit);
       } else {
         commit = d.commit();
       }