Error out with more useful message on "push :refs/changes/nnn"

Instead of logging an error in the server log, give a
message to the client letting them know that the usage
wasn't correct.

Bug: GERRIT-79
Signed-off-by: Shawn O. Pearce <sop@google.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/main/java/com/google/gerrit/server/ssh/Receive.java b/src/main/java/com/google/gerrit/server/ssh/Receive.java
index 91f9107a4c..132476f803 100644
--- a/src/main/java/com/google/gerrit/server/ssh/Receive.java
+++ b/src/main/java/com/google/gerrit/server/ssh/Receive.java
@@ -497,6 +497,11 @@ class Receive extends AbstractGitCommand {
 
   private void parseNewPatchSetCommand(final ReceiveCommand cmd,
       final Change.Id changeId) {
+    if (cmd.getType() != ReceiveCommand.Type.CREATE) {
+      reject(cmd, "invalid usage");
+      return;
+    }
+
     final Change changeEnt;
     try {
       changeEnt = db.changes().get(changeId);