X && Y || Z
binds operator precedence-wise as
(X && Y) || Z
not
X && (Y || Z)

so I am a little suspicious about...

vcl/source/window/menu.cxx
if ( ImplIsVisible( i ) && ( pData->eType == MENUITEM_IMAGE ) || ( pData->eType
== MENUITEM_STRINGIMAGE ))
which means
if ( (ImplIsVisible( i ) && ( pData->eType == MENUITEM_IMAGE )) || (
pData->eType == MENUITEM_STRINGIMAGE ))
is that what we really mean, or do we mean
if ( ImplIsVisible( i ) && (( pData->eType == MENUITEM_IMAGE ) || ( pData->eType
== MENUITEM_STRINGIMAGE )))
seeing as both MENUITEMs refer to "image"s of one type of another ?

similarly in unx/gtk/gdi/salnativewidgets-gtk.cxx
there is a confusing sequence of && || where one of them (the menu) section is
slightly different to the other ones, which makes me suspicious that it might be
intended to be the same as the others.

If they're currently correct, then lets just stick some brackets around it to
confirm it, but if not then the following patch might be what was intended. Just
a guess though