[Bug 55457] New: Robot Battle 1.4 crashes on startup after commit 08dc691d

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=55457

Bug ID: 55457
           Summary: Robot Battle 1.4 crashes on startup after commit
                    08dc691d
           Product: Wine
           Version: 8.13
          Hardware: x86-64
               URL: https://web.archive.org/web/20130317061354/http://www.
                    robotbattle.com/download/latest.php
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: mshtml
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail]
   Regression SHA1: 08dc691dfb410de7115db3f9c34b225327e21f67
      Distribution: ---

Created attachment 75018
  --> https://bugs.winehq.org/attachment.cgi?id=75018
Backtrace Log

Robot Battle 1.4 crashes on startup. A bisect found commit 08dc691d ("mshtml:
Explicitly hold ref to the plugin host in NPP_New.") is the cause.

I've set the URL field here to a working link for the installer.

It looks like a NULL dereference at IOleClientSite_AddRef when
container->plugin_host is failed to be created.

A simple patch that fixes this for me is to check for err before attempting
IOleClientSite_AddRef.