From 41642e0eb65614d6dea318ffc3bdae0a8c3c255a Mon Sep 17 00:00:00 2001
From: Raviteja Sunkara <raviteja@codeaurora.org>
Date: Fri, 22 Mar 2013 17:03:41 +0530
Subject: [PATCH] add null check to patchset object while creating descendent
 changes.

Without this fix, there had been a NullPointerException due to
database inconsistency(assumed it was caused because of a gerrit crash)

Change-Id: I0f7ac7dd9356afdd9021cd9db9e574edc8bcd1aa
---
 .../gerrit/server/events/EventFactory.java    | 23 +++++++++++++++----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/events/EventFactory.java b/gerrit-server/src/main/java/com/google/gerrit/server/events/EventFactory.java
index bc4d998c40..d556e7337b 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/events/EventFactory.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/events/EventFactory.java
@@ -188,11 +188,24 @@ public class EventFactory {
           }
         }
 
-        final RevId revId = db.patchSets().get(psId).getRevision();
-        for (PatchSetAncestor a : db.patchSetAncestors().descendantsOf(revId)) {
-          final PatchSet p = db.patchSets().get(a.getPatchSet());
-          final Change c = db.changes().get(p.getId().getParentKey());
-          ca.neededBy.add(newNeededBy(c, p));
+        final PatchSet ps = db.patchSets().get(psId);
+        if (ps == null) {
+          log.error("Error while generating the list of descendants for"
+              + " PatchSet " + psId + ": Cannot find PatchSet entry in"
+              + " database.");
+        } else {
+          final RevId revId = ps.getRevision();
+          for (PatchSetAncestor a : db.patchSetAncestors().descendantsOf(revId)) {
+            final PatchSet p = db.patchSets().get(a.getPatchSet());
+            if (p == null) {
+              log.error("Error while generating the list of descendants for"
+                  + " revision " + revId.get() + ": Cannot find PatchSet entry in"
+                  + " database for " + a.getPatchSet());
+              continue;
+            }
+            final Change c = db.changes().get(p.getId().getParentKey());
+            ca.neededBy.add(newNeededBy(c, p));
+          }
         }
       } finally {
         db.close();