On AIX, USE_IPV6 is set to 1 by default. It is not possible to unset USE_IPV6 by passing --disable-ipv6 to mozilla/nsprpub/configure.
Created attachment 82581 [details] [diff] [review] Proposed patch. Also remove _aix32in6.cfg. I also found that it is no longer necessary to have two separate files _aix32.cfg and _aix32in6.cfg, so I remove _aix32in6.cfg and keep _aix32.cfg.
wtc: This patch works fine for me on AIX 4.3.3. I used it in my Mozilla 1.0rc2 build, and it works as expected.
*** Bug 139449 has been marked as a duplicate of this bug. ***
I must clarify that the --disable-ipv6 option is for NSPR *developers*. NSPR *clients* should not configure NSPR with the --disable-ipv6 option. If the --disable-ipv6 option is specified, the NSPR build is nonstandard and will not be supported by the NSPR group.
Patch checked into the tip and NSPRPUB_PRE_4_2_CLIENT_BRANCH of NSPR. Note that the correct fix for the slow IPv6 DNS problem on AIX is in bug 144886. Do not solve that problem by configuring NSPR with --disable-ipv6. Please apply the patch in bug 144886.