From 1bf57848252863f30af3eed9b4aecdb4ce4b0635 Mon Sep 17 00:00:00 2001
From: Marco Miller <marco.miller@ericsson.com>
Date: Tue, 12 Jul 2016 11:40:36 -0400
Subject: [PATCH] Mergeability: handle UncheckedExecutionException like
 ExecutionException

Before this fix, UncheckedExecution exceptions caused by IllegalState
exceptions like "Duplicate stages not allowed" from jgit DirCacheBuilder
used to fail re-indexing. The stack trace available from the below
linked Issue is our recently noticed example of this.

This fix treats such exceptions the same way as Execution exceptions are
currently handled in MergeabilityCacheImpl. Should an
UncheckedExecutionException be thrown within checking mergeability from
re-indexing (or other threads), then the mergeability flag gets set to
false -as for a checked ExecutionException.

Bug: Issue 4249
Change-Id: I270db012c2796a7bebeb66ffe2969d7564daebe0
---
 .../com/google/gerrit/server/change/MergeabilityCacheImpl.java | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/MergeabilityCacheImpl.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/MergeabilityCacheImpl.java
index 826ebdd438..0f55e587c5 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/MergeabilityCacheImpl.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/MergeabilityCacheImpl.java
@@ -28,6 +28,7 @@ import com.google.common.collect.BiMap;
 import com.google.common.collect.ImmutableBiMap;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Sets;
+import com.google.common.util.concurrent.UncheckedExecutionException;
 import com.google.gerrit.extensions.client.SubmitType;
 import com.google.gerrit.reviewdb.client.Branch;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -269,7 +270,7 @@ public class MergeabilityCacheImpl implements MergeabilityCache {
     EntryKey key = new EntryKey(commit, into, submitType, mergeStrategy);
     try {
       return cache.get(key, new Loader(key, dest, repo, db));
-    } catch (ExecutionException e) {
+    } catch (ExecutionException | UncheckedExecutionException e) {
       log.error(String.format("Error checking mergeability of %s into %s (%s)",
             key.commit.name(), key.into.name(), key.submitType.name()),
           e.getCause());