[LyX/master] struct with virtual functions should have virtual destructor

[Stephan Witt]

commit 43d75a0796781ec8f5b9d33bfc544926a07aafd2
Author: Stephan Witt <sw...@lyx.org>
Date:   Wed Apr 30 23:12:41 2014 +0200

    struct with virtual functions should have virtual destructor

diff --git a/src/output_xhtml.h b/src/output_xhtml.h
index ac405cd..76f7bd9 100644
--- a/src/output_xhtml.h
+++ b/src/output_xhtml.h
@@ -45,7 +45,7 @@ struct StartTag
                bool keepempty = false) 
                : tag_(tag), attr_(attr), keepempty_(keepempty) {}
        ///
-       ~StartTag() {}
+       virtual ~StartTag() {}
        /// <tag_ attr_>
        virtual docstring writeTag() const;
        /// </tag_>