Created attachment 396785 [details]
dl.c sample code to demonstrate issue

Description of problem:
Calling dlclose twice with the same handle returns 0 (SUCCESS) despite the library having already been closed. If fact, dlclose will return 0 for all subsequent calls for the same handle.

Version-Release number of selected component (if applicable):
glibc-2.11.1-1

How reproducible:
Always

Steps to Reproduce:
1.Compile attached dl.c
2.Execute dl
3.
  
Actual results:
dlopen returned 153825312
dlclose call 1 returned 0
dlclose call 2 returned 0

Expected results:
dlopen returned 146464800
dlclose call 1 returned 0
dlclose call 2 returned -1
dlclose call 2: ��: shared object not open


Additional info:
The problem occurs on F-12 with glibc-2.11.1-1. The expected results are produced on F-11 using glibc-2.10.2-1.

The above problem stops asterisk initialising, since in main/loader.c, it uses the following code:
while (!dlclose(lib));
On F-11, using glibc-2.10.2-1, the loop terminates once all instances of the library have been closed. On F-12 with glibc-2.11.1-1 the loop never terminates.