Merge "Fix displaying diff for commit message"
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/Files.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/Files.java
index 1034c99c..1631d48 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/Files.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/Files.java
@@ -29,6 +29,7 @@
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -92,6 +93,9 @@
   @Override
   public FileResource parse(RevisionResource rev, IdString id)
       throws ResourceNotFoundException, IOException {
+    if (Patch.COMMIT_MSG.equals(id.get())) {
+      return new FileResource(rev, id.get());
+    }
     try (Repository repo = repoManager.openRepository(rev.getProject());
         RevWalk rw = new RevWalk(repo)) {
       RevTree tree = rw.parseTree(
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/FilesInCommitCollection.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/FilesInCommitCollection.java
index 736fe5d..64a5fb2 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/FilesInCommitCollection.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/FilesInCommitCollection.java
@@ -19,6 +19,7 @@
 import com.google.gerrit.extensions.restapi.IdString;
 import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestView;
+import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -46,6 +47,10 @@
   @Override
   public FileResource parse(CommitResource parent, IdString id)
       throws ResourceNotFoundException, IOException {
+    if (Patch.COMMIT_MSG.equals(id.get())) {
+      return new FileResource(parent.getProject(), parent.getCommit(),
+          id.get());
+    }
     return FileResource.create(repoManager, parent.getProject(),
         parent.getCommit(), id.get());
   }