Created attachment 341177 [details]
minimal example

Version-Release number of selected component (if applicable):
nspr-4.7.3-2.fc10

How reproducible:
100%

Steps to Reproduce:
1. run the attached minimal example
  
Actual results:
[root@xen86 ~]# ./test.c
==4354== Memcheck, a memory error detector.
==4354== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al.
==4354== Using LibVEX rev 1804, a library for dynamic binary translation.
==4354== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP.
==4354== Using valgrind-3.3.0, a dynamic binary instrumentation framework.
==4354== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al.
==4354== For more details, rerun with: -v
==4354==
==4354==
==4354== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 1)
==4354== malloc/free: in use at exit: 7,864 bytes in 80 blocks.
==4354== malloc/free: 83 allocs, 3 frees, 8,258 bytes allocated.
==4354== For counts of detected errors, rerun with: -v
==4354== searching for pointers to 80 not-freed blocks.
==4354== checked 121,232 bytes.
==4354==
==4354== 48 bytes in 1 blocks are possibly lost in loss record 8 of 19
==4354==    at 0x4A0739E: malloc (vg_replace_malloc.c:207)
==4354==    by 0x4C2C4A9: _PR_Getfd (prfdcach.c:141)
==4354==    by 0x4C44004: pt_SetMethods (ptio.c:3319)
==4354==    by 0x4C4527D: PR_Socket (ptio.c:3499)
==4354==    by 0x400634: main (in /root/a.out)
==4354==
==4354== LEAK SUMMARY:
==4354==    definitely lost: 0 bytes in 0 blocks.
==4354==      possibly lost: 48 bytes in 1 blocks.
==4354==    still reachable: 7,816 bytes in 79 blocks.
==4354==         suppressed: 0 bytes in 0 blocks.
==4354== Reachable blocks (those to which a pointer was found) are not shown.
==4354== To see them, rerun with: --leak-check=full --show-reachable=yes

Additional info:
encountered while investigating Bug 453612