[PATCH 14/16] comctl32/header: Avoid uninitialized memory passed to HDM_INSERTITEM, some fields are always copied

[Nikolay Sivov]

This fixes a valgrind warning http://kegel.com/wine/valgrind/logs/2009-11-27-12.53/vg-comctl32_header.txt

HDM_INSERTITEM has a "feature" to copy some fiels even if mask doesn't contain corresponding flags.

Changelog:
     - avoid uninitialized memory passed to HDM_INSERTITEM, some fields are always copied