Reviewed by John.

    Reviewed by John.

        - fixed <rdar://problem/4034603> REGRESSION (185-188): RadarWeb can't send enclosures anymore

        * WebView.subproj/WebFormDataStream.m:
        (closeCurrentStream): Release currentData when closing the stream.
        (advanceCurrentStream): Set up and retain currentData when the current stream is reading that data, so the
        data won't be released while in use.
        (formCreate): Initialize currentData to NULL.

        - fixed <rdar://problem/4037562> Tiger8A402: Help Viewer crashed when viewing help for iChat (infinite recursion in WebView)

        * WebView.subproj/WebView.m: (-[WebView _responderValidateUserInterfaceItem:]):
        Check for the case where we ourselves are the responder. This avoids an infinite loop.
        The actual code to perform operations avoids this with a global variable, but this lighter weight
        solution is sufficient here because validate operations don't call through to the next responder.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8793 268f45cc-cd09-0410-ab3c-d52691b4dbfc