typedef of unspecified type causes friend function documentation to be not documented

[scott-zhong]

Describe the bug
typedef of unspecified type causes friend function documentation to be not documented.

/**
 * \relates A
 *
 * An unspecified type.
 */
typedef unspecified my_type;

/**
 * A docs
 */
class A
{
public:
    friend void fun(my_type);
};

/**
 * fun docs
 */
void fun(my_type);

fun() is not documented and the warning warning: Member fun(my_type) (friend) of class A is not documented. is produced

Screenshots
1.8.9.1 - trunk (85eb55d)

To Reproduce
testcase.zip

Expected behavior
fun() is documented.

[paule32]

you define a type my_type based on unspecified.
so, either unspecified must be exists before you define my_type or you use an already existing type.
the next problem I see is, that you don't give the type an argument for the member declaration.
should it not be void fun(my_type arg1) ?

I think it is a usage problem.

[scott-zhong]

Argument name isn't required, especially if the function doesn't use the argument (you'll get a compiler warning about unused variable if you do).

I don't think this is a usage problem because even if we define unspecified type, Doxygen still thinks that it is an undocumented member. For example

struct unspecified
{
};

/**
 * \relates A
 *
 * An unspecified type.
 */
typedef unspecified my_type;

/**
 * A docs
 */
class A
{
public:
    friend void fun(my_type);
};

/**
 * fun docs
 */
void fun(my_type);

fun() would still be undocumented. Whereas if we switch to an int type then fun() is now documented.

/**
 * A docs
 */
class A
{
public:
    friend void fun(int);
};

/**
 * fun docs
 */
void fun(int);

[doxygen]

@scott-zhong The problem is the \relates command, which makes doxygen treat the typedef as a member of A, but then when resolving the type in fun's declaration it searches for the type in the global scope where it is not found, while for the friend declaration it is found.

In older versions of doxygen, the scope resolution was less strict and the member could still be found (which sometimes led to links to the wrong symbol).

[doxygen]

@scott-zhong Please verify if the referenced commit fixes the problem for you. Do not close the issue, this will be done automatically when the next official release becomes available.

[scott-zhong]

@doxygen verified the fix. Thank you!!!

[doxygen]

This issue was previously marked 'fixed but not released',
which means it should be fixed in doxygen version 1.11.0.
Please verify if this is indeed the case. Reopen the
issue if you think it is not fixed and please include any additional information
that you think can be relevant (preferably in the form of a self-contained example).