Do not get commit info until patchset is plubished

When using inline edit to make a change the revision number is not
available when the publish page is presented.  In that case do not
attempt to get the CommitInfo of the patchset because it will not
be available until after publishing the update.
diff --git a/src/main/java/com/googlesource/gerrit/plugins/chound/client/LabelPanel.java b/src/main/java/com/googlesource/gerrit/plugins/chound/client/LabelPanel.java
index cd3fcfe..9e86e27 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/chound/client/LabelPanel.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/chound/client/LabelPanel.java
@@ -42,30 +42,32 @@
   LabelPanel(final Panel panel) {
     final ChangeInfo change =
         panel.getObject(GerritUiExtensionPoint.Key.CHANGE_INFO).cast();
-    RevisionInfo rev =
+    final RevisionInfo rev =
         panel.getObject(GerritUiExtensionPoint.Key.REVISION_INFO).cast();
 
-    new RestApi("changes").id(change.id()).view("revisions").id(rev.id())
-        .view("commit").get(new AsyncCallback<CommitInfo>() {
-          @Override
-          public void onSuccess(CommitInfo result) {
-            if (result != null) {
-              displayDependsOn(result);
+    // revision might not be available when using inline edit
+    if (rev != null && !rev.isEdit()) {
+      new RestApi("changes").id(change.id()).view("revisions").id(rev.id())
+          .view("commit").get(new AsyncCallback<CommitInfo>() {
+            @Override
+            public void onSuccess(CommitInfo result) {
+              if (result != null) {
+                displayDependsOn(result);
+              }
             }
-          }
 
-          @Override
-          public void onFailure(Throwable caught) {
-            // never invoked
-          }
-        });
-
+            @Override
+            public void onFailure(Throwable caught) {
+              // never invoked
+            }
+          });
+    }
     new RestApi("changes").view("?q=message:" + change.changeId())
         .view("+NOT+change:" + change.changeId())
         .get(new AsyncCallback<NativeMap<ChangeInfo>>() {
           @Override
           public void onSuccess(NativeMap<ChangeInfo> result) {
-            if (!result.isEmpty()) {
+            if (result != null && !result.isEmpty()) {
               displayNeededBy(result);
             }
           }