CORBA25 — Type redefinition in derived interface

The discussion for issue 3525 shows that it is legal to redefine a type
in a derived interface, as in

interface B

;
interface D : B

;

However, I don't think that this legality is obvious from the text. On
page 3-52, it says that "inheritance causes all identifiers defined in
base interfaces to be visible in derived interfaces." Then, on page
3-56, it is said that "once a type has been defined anywhere within
the scope of a module, interface or valuetype, it may not be redefined
except within the scope of a nested module or interface."

Since B::S is not "defined" but only "visible" in D, and D is not a
nested interface but a derived interface, there seems to be a gray
area.

Proposed resolution:

Edit the first paragraph of 3.15.3 (Special Scoping Rules for Type
Names) on p 3-56 to read:

"Once a type has been defined anywhere within the scope of a module,
interface or valuetype, it may not be redefined except within the
scope of a nested module, interface or valuetype, or within the
scope of a derived interface or valuetype."

Edit the following example to include, after interface A, but before
the erroneous redefinition of ArgType,

interface B : A {
typedef long ArgType; // OK, redefined in derived interface
struct S

;
};

Make the suggested change clarifying the inheritance case