dlclose blocked by static-initialized member of templated class

[Jan Engelhardt <jengelh at inai dot de>]

Given the two snippets below, I observe that dlclose behaves like a no-op
under Linux x86_64 glibc-2.19.

1. Build module.cpp into module.so, build loader.c as a program.
2. Run the loader.
3. Observed behavior:
	xxinit
	#1 dlopen 0xwhatever
	#2 dlopen 0xwhatever
	Program done
	xxexit

4. What was expected:
	xxinit
	#1 dlopen 0xwhatever
	xxexit
	xxinit
	#2 dlopen 0xwhatever
	xxexit
	Program done

I can imagine that there is a justified reason related to libdl keeping 
the reference count artificially higher, turning dlclose into a no-op, 
though what exactly is going on?

-----8<-----(module.cpp)-----
#include <cstdio>
class nothing {};
template<typename _T> struct wrap {
	static const int foo;
};
template<typename _T> const int wrap<_T>::foo(42);
static __attribute__((constructor)) void xxinit(void) { printf("xxinit\n"); }
static __attribute__((destructor)) void xxexit(void) { printf("xxexit\n"); }
void magic(wrap<nothing> p)
{
	printf("%p\n", &p.foo); /* &p.foo causes the hold-up */
}
----->8------

-----8<------(loader.c)-----
#include <dlfcn.h>
#include <stdio.h>
int main(int argc, const char **argv)
{
	void *h;
	h = dlopen("./module.so", RTLD_NOW);
	printf("#1 dlopen %p\n", h);
	if (h != NULL)
		dlclose(h);
	h = dlopen("./module.so", RTLD_NOW);
	printf("#2 dlopen %p\n", h);
	if (h != NULL)
		dlclose(h);
	printf("Program done\n");
	return 0;
}
----->8-----