ChangeApiImpl: Don't catch RestApiException on rebase

RestApiException (and any subclass of it) is caught and rethrown as
a RestApiException with a generic message. This causes the actual
exception type and message to be lost.

Don't catch RestApiException; allow the original to propagate.

Also add tests in ChangeIT to verify behavior when rebasing with and
without the rebase permission.

Change-Id: Ia303dcf0b7158aafa82adfaeeaabd76a8a980b15

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/change/ChangeIT.java

@@ -383,6 +383,46 @@ public class ChangeIT extends AbstractDaemonTest {
     gApi.changes().id(changeId).current().rebase();
   }
 
+  @Test
+  public void rebaseNotAllowedWithoutPermission() throws Exception {
+    // Create two changes both with the same parent
+    PushOneCommit.Result r = createChange();
+    testRepo.reset("HEAD~1");
+    PushOneCommit.Result r2 = createChange();
+
+    // Approve and submit the first change
+    RevisionApi revision = gApi.changes().id(r.getChangeId()).current();
+    revision.review(ReviewInput.approve());
+    revision.submit();
+
+    // Rebase the second
+    String changeId = r2.getChangeId();
+    setApiUser(user);
+    exception.expect(AuthException.class);
+    exception.expectMessage("rebase not permitted");
+    gApi.changes().id(changeId).rebase();
+  }
+
+  @Test
+  public void rebaseAllowedWithPermission() throws Exception {
+    // Create two changes both with the same parent
+    PushOneCommit.Result r = createChange();
+    testRepo.reset("HEAD~1");
+    PushOneCommit.Result r2 = createChange();
+
+    // Approve and submit the first change
+    RevisionApi revision = gApi.changes().id(r.getChangeId()).current();
+    revision.review(ReviewInput.approve());
+    revision.submit();
+
+    grant(Permission.REBASE, project, "refs/heads/master", false, REGISTERED_USERS);
+
+    // Rebase the second
+    String changeId = r2.getChangeId();
+    setApiUser(user);
+    gApi.changes().id(changeId).rebase();
+  }
+
   @Test
   public void publish() throws Exception {
     PushOneCommit.Result r = createChange("refs/drafts/master");

gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java

@@ -340,7 +340,7 @@ class ChangeApiImpl implements ChangeApi {
   public void rebase(RebaseInput in) throws RestApiException {
     try {
       rebase.apply(change, in);
-    } catch (EmailException | OrmException | UpdateException | RestApiException | IOException e) {
+    } catch (EmailException | OrmException | UpdateException | IOException e) {
       throw new RestApiException("Cannot rebase change", e);
     }
   }