Don't unnecessarily NUL-terminate wxCharBuffer contents.

wxCharBuffer already initializes the last byte of the buffer it allocates to 0
so there is no need to do it explicitly.

Also don't allocate an extra byte, wxCharBuffer already adds one to the length
passed to it for the trailing NUL.

See #13885.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73141 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/html/htmlfilt.cpp

@@ -154,9 +154,8 @@ wxString wxHtmlFilterHTML::ReadFile(const wxFSFile& file) const
     else
     {
         size_t size = s->GetSize();
-        wxCharBuffer buf( size+1 );
+        wxCharBuffer buf( size );
         s->Read( buf.data(), size );
-        *(buf.data() + size) = 0;
         wxString tmpdoc( buf, wxConvISO8859_1);
 
         wxString charset = wxHtmlParser::ExtractCharsetInformation(tmpdoc);