Misleading PathConflictException when Rebasing

Since Gerrit nowadays handles Path Conflicts and (depending
on the Project Settings) tries to resolve them with a content
merge, there will also be failing rebases due to content merge
conflicts.

A user getting an error message pointing towards a path
conflict could obviously be confused, since (s)he is used to
Gerrit normally handling them or since it might not even be a
path conflict that caused the error.

Change-Id: I8574a78efbf130abfe0da8fc6ae65decbf6872a1

gerrit-server/src/main/java/com/google/gerrit/server/changedetail/PathConflictException.java

@@ -1,24 +0,0 @@
-// Copyright (C) 2012 The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.gerrit.server.changedetail;
-
-/** Indicates a path conflict during rebase or merge */
-public class PathConflictException extends Exception {
-  private static final long serialVersionUID = 1L;
-
-  public PathConflictException(String msg) {
-    super(msg);
-  }
-}

gerrit-server/src/main/java/com/google/gerrit/server/changedetail/RebaseChange.java

@@ -31,6 +31,7 @@ import com.google.gerrit.server.change.PatchSetInserter;
 import com.google.gerrit.server.change.PatchSetInserter.ValidatePolicy;
 import com.google.gerrit.server.change.RevisionResource;
 import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.git.MergeConflictException;
 import com.google.gerrit.server.git.MergeUtil;
 import com.google.gerrit.server.project.ChangeControl;
 import com.google.gerrit.server.project.InvalidChangeOperationException;
@@ -138,7 +139,7 @@ public class RebaseChange {
           uploader, baseCommit, mergeUtilFactory.create(
               changeControl.getProjectControl().getProjectState(), true),
           committerIdent, true, true, ValidatePolicy.GERRIT);
-    } catch (PathConflictException e) {
+    } catch (MergeConflictException e) {
       throw new IOException(e.getMessage());
     } finally {
       if (inserter != null) {
@@ -281,7 +282,7 @@ public class RebaseChange {
       boolean sendMail, boolean runHooks, ValidatePolicy validate)
           throws NoSuchChangeException,
       OrmException, IOException, InvalidChangeOperationException,
-      PathConflictException {
+      MergeConflictException {
     if (!change.currentPatchSetId().equals(patchSetId)) {
       throw new InvalidChangeOperationException("patch set is not current");
     }
@@ -338,7 +339,7 @@ public class RebaseChange {
       final ObjectInserter inserter, final RevCommit original,
       final RevCommit base, final MergeUtil mergeUtil,
       final PersonIdent committerIdent) throws IOException,
-      PathConflictException {
+      MergeConflictException {
 
     final RevCommit parentCommit = original.getParent(0);
 
@@ -351,8 +352,8 @@ public class RebaseChange {
     merger.merge(original, base);
 
     if (merger.getResultTreeId() == null) {
-      throw new PathConflictException(
+      throw new MergeConflictException(
-          "The change could not be rebased due to a path conflict during merge.");
+          "The change could not be rebased due to a conflict during merge.");
     }
 
     final CommitBuilder cb = new CommitBuilder();

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

@@ -32,6 +32,12 @@ public enum CommitMergeStatus {
                   + "\n"
                   + "Please rebase the change locally and upload the rebased commit for review."),
 
+  /** */
+  REBASE_MERGE_CONFLICT(
+      "The change could not be merged due to a conflict.\n"
+          + "\n"
+          + "Please rebase the change locally and upload the rebased commit for review."),
+
   /** */
   MISSING_DEPENDENCY(""),
 

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

@@ -20,10 +20,10 @@ import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.PatchSetApproval;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.change.PatchSetInserter.ValidatePolicy;
-import com.google.gerrit.server.changedetail.PathConflictException;
 import com.google.gerrit.server.changedetail.RebaseChange;
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CommitMergeStatus;
+import com.google.gerrit.server.git.MergeConflictException;
 import com.google.gerrit.server.git.MergeException;
 import com.google.gerrit.server.git.RebaseSorter;
 import com.google.gerrit.server.patch.PatchSetInfoFactory;
@@ -109,8 +109,8 @@ public class RebaseIfNecessary extends SubmitStrategy {
             newMergeTip.setStatusCode(CommitMergeStatus.CLEAN_REBASE);
             newCommits.put(newPatchSet.getId().getParentKey(), newMergeTip);
             setRefLogIdent(args.mergeUtil.getSubmitter(n));
-          } catch (PathConflictException e) {
+          } catch (MergeConflictException e) {
-            n.setStatusCode(CommitMergeStatus.PATH_CONFLICT);
+            n.setStatusCode(CommitMergeStatus.REBASE_MERGE_CONFLICT);
           } catch (NoSuchChangeException | OrmException | IOException
               | InvalidChangeOperationException e) {
             throw new MergeException("Cannot rebase " + n.name(), e);