Rename MergeException to IntegrationException

It's confusing to have MergeException and MergeConflictException be
two different types that don't share a hierarchy: if I have a merge
conflict, which one should I throw?

We've already started using the term "integrate" to mean "submit a
change and make it a part of the target branch". This is specifically
the situation in which MergeException was used, so let's just rename
it to IntegrationException.

Change-Id: I344c70bf8ffeb3a2823a65b5fcf09ea9bff82e72

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

@@ -25,7 +25,7 @@ import com.google.gerrit.extensions.webui.UiAction;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.reviewdb.server.ReviewDb;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.UpdateException;
 import com.google.gerrit.server.project.ChangeControl;
 import com.google.gerrit.server.project.InvalidChangeOperationException;
@@ -87,7 +87,7 @@ public class CherryPick implements RestModifyView<RevisionResource, CherryPickIn
       return json.create(ChangeJson.NO_OPTIONS).format(cherryPickedChangeId);
     } catch (InvalidChangeOperationException e) {
       throw new BadRequestException(e.getMessage());
-    } catch (MergeException | NoSuchChangeException e) {
+    } catch (IntegrationException | NoSuchChangeException e) {
       throw new ResourceConflictException(e.getMessage());
     }
   }

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

@@ -34,7 +34,7 @@ import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
 import com.google.gerrit.server.git.GitRepositoryManager;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeIdenticalTreeException;
 import com.google.gerrit.server.git.MergeUtil;
 import com.google.gerrit.server.git.UpdateException;
@@ -112,7 +112,7 @@ public class CherryPickChange {
       final RefControl refControl) throws NoSuchChangeException,
       OrmException, MissingObjectException,
       IncorrectObjectTypeException, IOException,
-      InvalidChangeOperationException, MergeException, UpdateException,
+      InvalidChangeOperationException, IntegrationException, UpdateException,
       RestApiException {
 
     if (Strings.isNullOrEmpty(ref)) {
@@ -195,7 +195,7 @@ public class CherryPickChange {
           return newChange.getId();
         }
       } catch (MergeIdenticalTreeException | MergeConflictException e) {
-        throw new MergeException("Cherry pick failed: " + e.getMessage());
+        throw new IntegrationException("Cherry pick failed: " + e.getMessage());
       }
     } catch (RepositoryNotFoundException e) {
       throw new NoSuchChangeException(change.getId(), e);

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

@@ -34,7 +34,7 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.cache.CacheModule;
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.strategy.SubmitStrategyFactory;
 import com.google.gerrit.server.project.NoSuchProjectException;
 import com.google.inject.Inject;
@@ -199,7 +199,7 @@ public class MergeabilityCacheImpl implements MergeabilityCache {
 
     @Override
     public Boolean call()
-        throws NoSuchProjectException, MergeException, IOException {
+        throws NoSuchProjectException, IntegrationException, IOException {
       if (key.into.equals(ObjectId.zeroId())) {
         return true; // Assume yes on new branch.
       }

gerrit-server/src/main/java/com/google/gerrit/server/git/IntegrationException.java

@@ -14,19 +14,19 @@
 
 package com.google.gerrit.server.git;
 
-/** Indicates the current branch's queue cannot be processed at this time. */
+/** Indicates an integration operation (see {@link MergeOp}) failed. */
-public class MergeException extends Exception {
+public class IntegrationException extends Exception {
   private static final long serialVersionUID = 1L;
 
-  public MergeException(String msg) {
+  public IntegrationException(String msg) {
     super(msg);
   }
 
-  public MergeException(Throwable why) {
+  public IntegrationException(Throwable why) {
     super(why);
   }
 
-  public MergeException(String msg, Throwable why) {
+  public IntegrationException(String msg, Throwable why) {
     super(msg, why);
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeOp.java

@@ -226,10 +226,12 @@ public class MergeOp {
     mergeTips = new HashMap<>();
   }
 
-  private void setDestProject(Branch.NameKey destBranch) throws MergeException {
+  private void setDestProject(Branch.NameKey destBranch)
+      throws IntegrationException {
     destProject = projectCache.get(destBranch.getParentKey());
     if (destProject == null) {
-      throw new MergeException("No such project: " + destBranch.getParentKey());
+      throw new IntegrationException(
+          "No such project: " + destBranch.getParentKey());
     }
   }
 
@@ -376,7 +378,7 @@ public class MergeOp {
       }
       try {
         integrateIntoHistory(cs, caller);
-      } catch (MergeException e) {
+      } catch (IntegrationException e) {
         logError("Merge Conflict", e);
         throw new ResourceConflictException("Merge Conflict", e);
       }
@@ -387,7 +389,8 @@ public class MergeOp {
   }
 
   private void integrateIntoHistory(ChangeSet cs, IdentifiedUser caller)
-      throws MergeException, NoSuchChangeException, ResourceConflictException {
+      throws IntegrationException, NoSuchChangeException,
+      ResourceConflictException {
     logDebug("Beginning merge attempt on {}", cs);
     Map<Branch.NameKey, ListMultimap<SubmitType, ChangeData>> toSubmit =
         new HashMap<>();
@@ -450,9 +453,9 @@ public class MergeOp {
           + "abandoning open changes");
       abandonAllOpenChanges(noProject.project());
     } catch (OrmException e) {
-      throw new MergeException("Cannot query the database", e);
+      throw new IntegrationException("Cannot query the database", e);
     } catch (IOException e) {
-      throw new MergeException("Cannot query the database", e);
+      throw new IntegrationException("Cannot query the database", e);
     } finally {
       closeRepository();
     }
@@ -460,7 +463,7 @@ public class MergeOp {
 
   private MergeTip preMerge(SubmitStrategy strategy,
       List<ChangeData> submitted, CodeReviewCommit branchTip)
-      throws MergeException, OrmException {
+      throws IntegrationException, OrmException {
     logDebug("Running submit strategy {} for {} commits {}",
         strategy.getClass().getSimpleName(), submitted.size(), submitted);
     List<CodeReviewCommit> toMerge = new ArrayList<>(submitted.size());
@@ -479,20 +482,20 @@ public class MergeOp {
 
   private SubmitStrategy createStrategy(Branch.NameKey destBranch,
       SubmitType submitType, CodeReviewCommit branchTip, IdentifiedUser caller)
-      throws MergeException, NoSuchProjectException {
+      throws IntegrationException, NoSuchProjectException {
     return submitStrategyFactory.create(submitType, db, repo, rw, inserter,
         canMergeFlag, getAlreadyAccepted(branchTip), destBranch, caller);
   }
 
   private void openRepository(Project.NameKey name)
-      throws MergeException, NoSuchProjectException {
+      throws IntegrationException, NoSuchProjectException {
     try {
       repo = repoManager.openRepository(name);
     } catch (RepositoryNotFoundException notFound) {
       throw new NoSuchProjectException(name, notFound);
     } catch (IOException err) {
       String m = "Error opening repository \"" + name.get() + '"';
-      throw new MergeException(m, err);
+      throw new IntegrationException(m, err);
     }
 
     rw = CodeReviewCommit.newRevWalk(repo);
@@ -517,7 +520,7 @@ public class MergeOp {
   }
 
   private RefUpdate getPendingRefUpdate(Branch.NameKey destBranch)
-      throws MergeException {
+      throws IntegrationException {
 
     if (pendingRefUpdates.containsKey(destBranch)) {
       logDebug("Access cached open branch {}: {}", destBranch.get(),
@@ -534,8 +537,8 @@ public class MergeOp {
         branchTip = null;
         branchUpdate.setExpectedOldObjectId(ObjectId.zeroId());
       } else {
-        throw new MergeException("The destination branch " + destBranch.get()
+        throw new IntegrationException("The destination branch "
-            + " does not exist anymore.");
+            + destBranch.get() + " does not exist anymore.");
       }
 
       logDebug("Opened branch {}: {}", destBranch.get(), branchTip);
@@ -543,12 +546,12 @@ public class MergeOp {
       openBranches.put(destBranch, branchTip);
       return branchUpdate;
     } catch (IOException e) {
-      throw new MergeException("Cannot open branch", e);
+      throw new IntegrationException("Cannot open branch", e);
     }
   }
 
   private CodeReviewCommit getBranchTip(Branch.NameKey destBranch)
-      throws MergeException {
+      throws IntegrationException {
     if (openBranches.containsKey(destBranch)) {
       return openBranches.get(destBranch);
     } else {
@@ -558,7 +561,7 @@ public class MergeOp {
   }
 
   private Set<RevCommit> getAlreadyAccepted(CodeReviewCommit branchTip)
-      throws MergeException {
+      throws IntegrationException {
     Set<RevCommit> alreadyAccepted = new HashSet<>();
 
     if (branchTip != null) {
@@ -574,7 +577,7 @@ public class MergeOp {
         }
       }
     } catch (IOException e) {
-      throw new MergeException(
+      throw new IntegrationException(
           "Failed to determine already accepted commits.", e);
     }
 
@@ -583,7 +586,7 @@ public class MergeOp {
   }
 
   private ListMultimap<SubmitType, ChangeData> validateChangeList(
-      Collection<ChangeData> submitted) throws MergeException {
+      Collection<ChangeData> submitted) throws IntegrationException {
     logDebug("Validating {} changes", submitted.size());
     ListMultimap<SubmitType, ChangeData> toSubmit = ArrayListMultimap.create();
 
@@ -591,7 +594,7 @@ public class MergeOp {
     try {
       allRefs = repo.getRefDatabase().getRefs(ALL);
     } catch (IOException e) {
-      throw new MergeException(e.getMessage(), e);
+      throw new IntegrationException(e.getMessage(), e);
     }
 
     Set<ObjectId> tips = new HashSet<>();
@@ -607,7 +610,7 @@ public class MergeOp {
         // Reload change in case index was stale.
         chg = cd.reloadChange();
       } catch (OrmException e) {
-        throw new MergeException("Failed to validate changes", e);
+        throw new IntegrationException("Failed to validate changes", e);
       }
       Change.Id changeId = cd.getId();
       if (chg.getStatus() != Change.Status.NEW) {
@@ -625,7 +628,7 @@ public class MergeOp {
       try {
         ps = cd.currentPatchSet();
       } catch (OrmException e) {
-        throw new MergeException("Cannot query the database", e);
+        throw new IntegrationException("Cannot query the database", e);
       }
       if (ps == null || ps.getRevision() == null
           || ps.getRevision().get() == null) {
@@ -718,7 +721,7 @@ public class MergeOp {
   }
 
   private RefUpdate updateBranch(Branch.NameKey destBranch)
-      throws MergeException {
+      throws IntegrationException {
     RefUpdate branchUpdate = getPendingRefUpdate(destBranch);
     CodeReviewCommit branchTip = getBranchTip(destBranch);
 
@@ -746,7 +749,7 @@ public class MergeOp {
             new ProjectConfig(destProject.getProject().getNameKey());
         cfg.load(repo, currentTip);
       } catch (Exception e) {
-        throw new MergeException("Submit would store invalid"
+        throw new IntegrationException("Submit would store invalid"
             + " project configuration " + currentTip.name() + " for "
             + destProject.getProject().getName(), e);
       }
@@ -782,13 +785,13 @@ public class MergeOp {
           return branchUpdate;
 
         case LOCK_FAILURE:
-          throw new MergeException("Failed to lock " + branchUpdate.getName());
+          throw new IntegrationException("Failed to lock " + branchUpdate.getName());
         default:
           throw new IOException(branchUpdate.getResult().name()
               + '\n' + branchUpdate);
       }
     } catch (IOException e) {
-      throw new MergeException("Cannot update " + branchUpdate.getName(), e);
+      throw new IntegrationException("Cannot update " + branchUpdate.getName(), e);
     }
   }
 
@@ -820,7 +823,7 @@ public class MergeOp {
 
   private void updateChangeStatus(List<ChangeData> submitted,
       Branch.NameKey destBranch, boolean dryRun, IdentifiedUser caller)
-      throws NoSuchChangeException, MergeException, ResourceConflictException,
+      throws NoSuchChangeException, IntegrationException, ResourceConflictException,
       OrmException {
     if (!dryRun) {
       logDebug("Updating change status for {} changes", submitted.size());
@@ -896,8 +899,8 @@ public class MergeOp {
 
           case MISSING_DEPENDENCY:
             logDebug("Change {} is missing dependency", c.getId());
-            throw new MergeException("Cannot merge " + commit.name() + "\n"
+            throw new IntegrationException(
-                + s.getMessage());
+                "Cannot merge " + commit.name() + "\n" + s.getMessage());
 
           case REVISION_GONE:
             logDebug("Commit not found for change {}", c.getId());
@@ -910,12 +913,12 @@ public class MergeOp {
                 c.currentPatchSetId());
             msg.setMessage("Failed to read commit for this patch set");
             setNew(commit.notes(), msg);
-            throw new MergeException(msg.getMessage());
+            throw new IntegrationException(msg.getMessage());
 
           default:
             msg = message(c, "Unspecified merge failure: " + s.name());
             setNew(commit.notes(), msg);
-            throw new MergeException(msg.getMessage());
+            throw new IntegrationException(msg.getMessage());
         }
       } catch (OrmException | IOException err) {
         logWarn("Error updating change status for " + c.getId(), err);

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeUtil.java

@@ -139,7 +139,7 @@ public class MergeUtil {
 
   public CodeReviewCommit getFirstFastForward(
       final CodeReviewCommit mergeTip, final RevWalk rw,
-      final List<CodeReviewCommit> toMerge) throws MergeException {
+      final List<CodeReviewCommit> toMerge) throws IntegrationException {
     for (final Iterator<CodeReviewCommit> i = toMerge.iterator(); i.hasNext();) {
       try {
         final CodeReviewCommit n = i.next();
@@ -148,19 +148,20 @@ public class MergeUtil {
           return n;
         }
       } catch (IOException e) {
-        throw new MergeException("Cannot fast-forward test during merge", e);
+        throw new IntegrationException(
+            "Cannot fast-forward test during merge", e);
       }
     }
     return mergeTip;
   }
 
   public List<CodeReviewCommit> reduceToMinimalMerge(MergeSorter mergeSorter,
-      Collection<CodeReviewCommit> toSort) throws MergeException {
+      Collection<CodeReviewCommit> toSort) throws IntegrationException {
     List<CodeReviewCommit> result = new ArrayList<>();
     try {
       result.addAll(mergeSorter.sort(toSort));
     } catch (IOException e) {
-      throw new MergeException("Branch head sorting failed", e);
+      throw new IntegrationException("Branch head sorting failed", e);
     }
     Collections.sort(result, CodeReviewCommit.ORDER);
     return result;
@@ -346,7 +347,7 @@ public class MergeUtil {
   public boolean canMerge(final MergeSorter mergeSorter,
       final Repository repo, final CodeReviewCommit mergeTip,
       final CodeReviewCommit toMerge)
-      throws MergeException {
+      throws IntegrationException {
     if (hasMissingDependencies(mergeSorter, toMerge)) {
       return false;
     }
@@ -360,13 +361,13 @@ public class MergeUtil {
     } catch (NoMergeBaseException e) {
       return false;
     } catch (IOException e) {
-      throw new MergeException("Cannot merge " + toMerge.name(), e);
+      throw new IntegrationException("Cannot merge " + toMerge.name(), e);
     }
   }
 
   public boolean canFastForward(MergeSorter mergeSorter,
       CodeReviewCommit mergeTip, CodeReviewRevWalk rw, CodeReviewCommit toMerge)
-      throws MergeException {
+      throws IntegrationException {
     if (hasMissingDependencies(mergeSorter, toMerge)) {
       return false;
     }
@@ -374,13 +375,13 @@ public class MergeUtil {
     try {
       return mergeTip == null || rw.isMergedInto(mergeTip, toMerge);
     } catch (IOException e) {
-      throw new MergeException("Cannot fast-forward test during merge", e);
+      throw new IntegrationException("Cannot fast-forward test during merge", e);
     }
   }
 
   public boolean canCherryPick(MergeSorter mergeSorter, Repository repo,
       CodeReviewCommit mergeTip, CodeReviewRevWalk rw, CodeReviewCommit toMerge)
-      throws MergeException {
+      throws IntegrationException {
     if (mergeTip == null) {
       // The branch is unborn. Fast-forward is possible.
       //
@@ -404,7 +405,7 @@ public class MergeUtil {
         m.setBase(toMerge.getParent(0));
         return m.merge(mergeTip, toMerge);
       } catch (IOException e) {
-        throw new MergeException("Cannot merge " + toMerge.name(), e);
+        throw new IntegrationException("Cannot merge " + toMerge.name(), e);
       }
     }
 
@@ -419,11 +420,11 @@ public class MergeUtil {
   }
 
   public boolean hasMissingDependencies(final MergeSorter mergeSorter,
-      final CodeReviewCommit toMerge) throws MergeException {
+      final CodeReviewCommit toMerge) throws IntegrationException {
     try {
       return !mergeSorter.sort(Collections.singleton(toMerge)).contains(toMerge);
     } catch (IOException e) {
-      throw new MergeException("Branch head sorting failed", e);
+      throw new IntegrationException("Branch head sorting failed", e);
     }
   }
 
@@ -450,7 +451,8 @@ public class MergeUtil {
   public CodeReviewCommit mergeOneCommit(PersonIdent author,
       PersonIdent committer, Repository repo, CodeReviewRevWalk rw,
       ObjectInserter inserter, RevFlag canMergeFlag, Branch.NameKey destBranch,
-      CodeReviewCommit mergeTip, CodeReviewCommit n) throws MergeException {
+      CodeReviewCommit mergeTip, CodeReviewCommit n)
+      throws IntegrationException {
     final ThreeWayMerger m = newThreeWayMerger(repo, inserter);
     try {
       if (m.merge(new AnyObjectId[] {mergeTip, n})) {
@@ -464,10 +466,10 @@ public class MergeUtil {
         failed(rw, canMergeFlag, mergeTip, n,
             getCommitMergeStatus(e.getReason()));
       } catch (IOException e2) {
-        throw new MergeException("Cannot merge " + n.name(), e);
+        throw new IntegrationException("Cannot merge " + n.name(), e);
       }
     } catch (IOException e) {
-      throw new MergeException("Cannot merge " + n.name(), e);
+      throw new IntegrationException("Cannot merge " + n.name(), e);
     }
     return mergeTip;
   }
@@ -640,7 +642,7 @@ public class MergeUtil {
 
   public void markCleanMerges(final RevWalk rw,
       final RevFlag canMergeFlag, final CodeReviewCommit mergeTip,
-      final Set<RevCommit> alreadyAccepted) throws MergeException {
+      final Set<RevCommit> alreadyAccepted) throws IntegrationException {
     if (mergeTip == null) {
       // If mergeTip is null here, branchTip was null, indicating a new branch
       // at the start of the merge process. We also elected to merge nothing,
@@ -665,7 +667,7 @@ public class MergeUtil {
         }
       }
     } catch (IOException e) {
-      throw new MergeException("Cannot mark clean merges", e);
+      throw new IntegrationException("Cannot mark clean merges", e);
     }
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/CherryPick.java

@@ -30,7 +30,7 @@ import com.google.gerrit.server.git.BatchUpdate.RepoContext;
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CommitMergeStatus;
 import com.google.gerrit.server.git.GroupCollector;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeIdenticalTreeException;
 import com.google.gerrit.server.git.MergeTip;
 import com.google.gerrit.server.git.UpdateException;
@@ -62,7 +62,7 @@ public class CherryPick extends SubmitStrategy {
 
   @Override
   protected MergeTip _run(CodeReviewCommit branchTip,
-      Collection<CodeReviewCommit> toMerge) throws MergeException {
+      Collection<CodeReviewCommit> toMerge) throws IntegrationException {
     MergeTip mergeTip = new MergeTip(branchTip, toMerge);
     List<CodeReviewCommit> sorted = CodeReviewCommit.ORDER.sortedCopy(toMerge);
     boolean first = true;
@@ -83,7 +83,8 @@ public class CherryPick extends SubmitStrategy {
       }
       u.execute();
     } catch (UpdateException | RestApiException e) {
-      throw new MergeException("Cannot cherry-pick onto " + args.destBranch);
+      throw new IntegrationException(
+          "Cannot cherry-pick onto " + args.destBranch);
     }
     // TODO(dborowitz): When BatchUpdate is hoisted out of CherryPick,
     // SubmitStrategy should probably no longer return MergeTip, instead just
@@ -214,7 +215,8 @@ public class CherryPick extends SubmitStrategy {
     }
 
     @Override
-    public void updateRepo(RepoContext ctx) throws MergeException, IOException {
+    public void updateRepo(RepoContext ctx)
+        throws IntegrationException, IOException {
       if (args.mergeUtil.hasMissingDependencies(args.mergeSorter, toMerge)) {
         // One or more dependencies were not met. The status was already marked
         // on the commit so we have nothing further to perform at this time.
@@ -249,7 +251,7 @@ public class CherryPick extends SubmitStrategy {
 
   @Override
   public boolean dryRun(CodeReviewCommit mergeTip, CodeReviewCommit toMerge)
-      throws MergeException {
+      throws IntegrationException {
     return args.mergeUtil.canCherryPick(args.mergeSorter, args.repo,
         mergeTip, args.rw, toMerge);
   }

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/FastForwardOnly.java

@@ -16,7 +16,7 @@ package com.google.gerrit.server.git.strategy;
 
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CommitMergeStatus;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeTip;
 
 import java.util.Collection;
@@ -29,7 +29,7 @@ public class FastForwardOnly extends SubmitStrategy {
 
   @Override
   protected MergeTip _run(final CodeReviewCommit branchTip,
-      final Collection<CodeReviewCommit> toMerge) throws MergeException {
+      final Collection<CodeReviewCommit> toMerge) throws IntegrationException {
     MergeTip mergeTip = new MergeTip(branchTip, toMerge);
     List<CodeReviewCommit> sorted = args.mergeUtil.reduceToMinimalMerge(
         args.mergeSorter, toMerge);
@@ -56,7 +56,7 @@ public class FastForwardOnly extends SubmitStrategy {
 
   @Override
   public boolean dryRun(CodeReviewCommit mergeTip,
-      CodeReviewCommit toMerge) throws MergeException {
+      CodeReviewCommit toMerge) throws IntegrationException {
     return args.mergeUtil.canFastForward(args.mergeSorter, mergeTip, args.rw,
         toMerge);
   }

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/MergeAlways.java

@@ -15,7 +15,7 @@
 package com.google.gerrit.server.git.strategy;
 
 import com.google.gerrit.server.git.CodeReviewCommit;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeTip;
 
 import org.eclipse.jgit.lib.PersonIdent;
@@ -30,7 +30,7 @@ public class MergeAlways extends SubmitStrategy {
 
   @Override
   protected MergeTip _run(CodeReviewCommit branchTip,
-      Collection<CodeReviewCommit> toMerge) throws MergeException {
+      Collection<CodeReviewCommit> toMerge) throws IntegrationException {
   List<CodeReviewCommit> sorted = args.mergeUtil.reduceToMinimalMerge(args.mergeSorter, toMerge);
     MergeTip mergeTip;
     if (branchTip == null) {
@@ -62,7 +62,7 @@ public class MergeAlways extends SubmitStrategy {
 
   @Override
   public boolean dryRun(CodeReviewCommit mergeTip, CodeReviewCommit toMerge)
-      throws MergeException {
+      throws IntegrationException {
     return args.mergeUtil.canMerge(args.mergeSorter, args.repo, mergeTip,
         toMerge);
   }

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/MergeIfNecessary.java

@@ -15,7 +15,7 @@
 package com.google.gerrit.server.git.strategy;
 
 import com.google.gerrit.server.git.CodeReviewCommit;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeTip;
 
 import org.eclipse.jgit.lib.PersonIdent;
@@ -30,7 +30,7 @@ public class MergeIfNecessary extends SubmitStrategy {
 
   @Override
   protected MergeTip _run(CodeReviewCommit branchTip,
-      Collection<CodeReviewCommit> toMerge) throws MergeException {
+      Collection<CodeReviewCommit> toMerge) throws IntegrationException {
     List<CodeReviewCommit> sorted =
         args.mergeUtil.reduceToMinimalMerge(args.mergeSorter, toMerge);
     MergeTip mergeTip;
@@ -67,7 +67,7 @@ public class MergeIfNecessary extends SubmitStrategy {
 
   @Override
   public boolean dryRun(CodeReviewCommit mergeTip, CodeReviewCommit toMerge)
-      throws MergeException {
+      throws IntegrationException {
     return args.mergeUtil.canFastForward(
           args.mergeSorter, mergeTip, args.rw, toMerge)
         || args.mergeUtil.canMerge(

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/RebaseIfNecessary.java

@@ -25,7 +25,7 @@ import com.google.gerrit.server.change.RebaseChangeOp;
 import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CommitMergeStatus;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeTip;
 import com.google.gerrit.server.git.RebaseSorter;
 import com.google.gerrit.server.git.UpdateException;
@@ -60,7 +60,7 @@ public class RebaseIfNecessary extends SubmitStrategy {
 
   @Override
   protected MergeTip _run(final CodeReviewCommit branchTip,
-      final Collection<CodeReviewCommit> toMerge) throws MergeException {
+      final Collection<CodeReviewCommit> toMerge) throws IntegrationException {
     MergeTip mergeTip = new MergeTip(branchTip, toMerge);
     List<CodeReviewCommit> sorted = sort(toMerge);
     while (!sorted.isEmpty()) {
@@ -113,11 +113,11 @@ public class RebaseIfNecessary extends SubmitStrategy {
             setRefLogIdent();
           } catch (MergeConflictException e) {
             n.setStatusCode(CommitMergeStatus.REBASE_MERGE_CONFLICT);
-            throw new MergeException(
+            throw new IntegrationException(
                 "Cannot rebase " + n.name() + ": " + e.getMessage(), e);
           } catch (NoSuchChangeException | OrmException | IOException
               | RestApiException | UpdateException e) {
-            throw new MergeException("Cannot rebase " + n.name(), e);
+            throw new IntegrationException("Cannot rebase " + n.name(), e);
           }
         }
 
@@ -142,7 +142,7 @@ public class RebaseIfNecessary extends SubmitStrategy {
               mergeTip.getCurrentTip(), args.alreadyAccepted);
           setRefLogIdent();
         } catch (IOException e) {
-          throw new MergeException("Cannot merge " + n.name(), e);
+          throw new IntegrationException("Cannot merge " + n.name(), e);
         }
       }
 
@@ -153,14 +153,14 @@ public class RebaseIfNecessary extends SubmitStrategy {
   }
 
   private List<CodeReviewCommit> sort(Collection<CodeReviewCommit> toSort)
-      throws MergeException {
+      throws IntegrationException {
     try {
       List<CodeReviewCommit> result = new RebaseSorter(
           args.rw, args.alreadyAccepted, args.canMergeFlag).sort(toSort);
       Collections.sort(result, CodeReviewCommit.ORDER);
       return result;
     } catch (IOException e) {
-      throw new MergeException("Commit sorting failed", e);
+      throw new IntegrationException("Commit sorting failed", e);
     }
   }
 
@@ -187,7 +187,7 @@ public class RebaseIfNecessary extends SubmitStrategy {
 
   @Override
   public boolean dryRun(CodeReviewCommit mergeTip, CodeReviewCommit toMerge)
-      throws MergeException {
+      throws IntegrationException {
     return !args.mergeUtil.hasMissingDependencies(args.mergeSorter, toMerge)
         && args.mergeUtil.canCherryPick(args.mergeSorter, args.repo, mergeTip,
             args.rw, toMerge);

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/SubmitStrategy.java

@@ -25,7 +25,7 @@ import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeSorter;
 import com.google.gerrit.server.git.MergeTip;
 import com.google.gerrit.server.git.MergeUtil;
@@ -124,10 +124,10 @@ public abstract class SubmitStrategy {
    *        this submit strategy. Implementations are responsible for ordering
    *        of commits, and should not modify the input in place.
    * @return the new merge tip.
-   * @throws MergeException
+   * @throws IntegrationException
    */
   public final MergeTip run(final CodeReviewCommit currentTip,
-      final Collection<CodeReviewCommit> toMerge) throws MergeException {
+      final Collection<CodeReviewCommit> toMerge) throws IntegrationException {
     refLogIdent = null;
     checkState(args.caller != null);
     return _run(currentTip, toMerge);
@@ -135,7 +135,7 @@ public abstract class SubmitStrategy {
 
   /** @see #run(CodeReviewCommit, Collection) */
   protected abstract MergeTip _run(CodeReviewCommit currentTip,
-      Collection<CodeReviewCommit> toMerge) throws MergeException;
+      Collection<CodeReviewCommit> toMerge) throws IntegrationException;
 
   /**
    * Checks whether the given commit can be merged.
@@ -147,10 +147,10 @@ public abstract class SubmitStrategy {
    * @param toMerge the commit that should be checked.
    * @return {@code true} if the given commit can be merged, otherwise
    *         {@code false}
-   * @throws MergeException
+   * @throws IntegrationException
    */
   public abstract boolean dryRun(CodeReviewCommit mergeTip,
-      CodeReviewCommit toMerge) throws MergeException;
+      CodeReviewCommit toMerge) throws IntegrationException;
 
   /**
    * Returns the identity that should be used for reflog entries when updating

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/SubmitStrategyFactory.java

@@ -23,7 +23,7 @@ import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.change.RebaseChangeOp;
 import com.google.gerrit.server.git.BatchUpdate;
 import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.MergeUtil;
 import com.google.gerrit.server.index.ChangeIndexer;
 import com.google.gerrit.server.patch.PatchSetInfoFactory;
@@ -90,7 +90,7 @@ public class SubmitStrategyFactory {
       Repository repo, CodeReviewRevWalk rw, ObjectInserter inserter,
       RevFlag canMergeFlag, Set<RevCommit> alreadyAccepted,
       Branch.NameKey destBranch, IdentifiedUser caller)
-      throws MergeException, NoSuchProjectException {
+      throws IntegrationException, NoSuchProjectException {
     ProjectState project = getProject(destBranch);
     SubmitStrategy.Arguments args = new SubmitStrategy.Arguments(
         identifiedUserFactory, myIdent, db, batchUpdateFactory,
@@ -111,7 +111,7 @@ public class SubmitStrategyFactory {
       default:
         final String errorMsg = "No submit strategy for: " + submitType;
         log.error(errorMsg);
-        throw new MergeException(errorMsg);
+        throw new IntegrationException(errorMsg);
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ConflictsPredicate.java

@@ -22,7 +22,7 @@ import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
-import com.google.gerrit.server.git.MergeException;
+import com.google.gerrit.server.git.IntegrationException;
 import com.google.gerrit.server.git.strategy.SubmitStrategy;
 import com.google.gerrit.server.project.NoSuchProjectException;
 import com.google.gerrit.server.project.ProjectCache;
@@ -129,7 +129,8 @@ class ConflictsPredicate extends OrPredicate<ChangeData> {
             conflicts = !strategy.dryRun(commit, otherCommit);
             args.conflictsCache.put(conflictsKey, conflicts);
             return conflicts;
-          } catch (MergeException | NoSuchProjectException | IOException e) {
+          } catch (IntegrationException | NoSuchProjectException
+              | IOException e) {
             throw new IllegalStateException(e);
           }
         }
@@ -148,7 +149,7 @@ class ConflictsPredicate extends OrPredicate<ChangeData> {
         }
 
         private Set<RevCommit> getAlreadyAccepted(Repository repo, RevWalk rw,
-            CodeReviewCommit tip) throws MergeException {
+            CodeReviewCommit tip) throws IntegrationException {
           Set<RevCommit> alreadyAccepted = Sets.newHashSet();
 
           if (tip != null) {
@@ -164,7 +165,7 @@ class ConflictsPredicate extends OrPredicate<ChangeData> {
               }
             }
           } catch (IOException e) {
-            throw new MergeException(
+            throw new IntegrationException(
                 "Failed to determine already accepted commits.", e);
           }