* Ignore services in nsswitch.conf that cannot be found (like

"mdns4_mininal" on Ubuntu).  This is a fix for NIXPKGS-79.  It
  doesn't *quite* fix the problem in all cases (there might be people
  actually using mDNS; they should just run the "nscd" daemon) but at
  least it should keep curl from failing in Nixpkgs downloads.

svn path=/nixpkgs/branches/stdenv-updates/; revision=11487

pkgs/development/libraries/glibc-2.7/default.nix

@@ -16,6 +16,31 @@ stdenv.mkDerivation {
 
   inherit (stdenv) is64bit;
 
+  patches = [
+    /* Fix for NIXPKGS-79: when doing host name lookups, when
+       nsswitch.conf contains a line like
+       
+         hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
+
+       don't return an error when mdns4_minimal can't be found.  This
+       is a bug in Glibc: when a service can't be found, NSS should
+       continue to the next service unless "UNAVAIL=return" is set.
+       ("NOTFOUND=return" refers to the service returning a NOTFOUND
+       error, not the service itself not being found.)  The reason is
+       that the "status" variable (while initialised to UNAVAIL) is
+       outside of the loop that iterates over the services, the
+       "files" service sets status to NOTFOUND.  So when the call to
+       find "mdns4_minimal" fails, "status" will still be NOTFOUND,
+       and it will return instead of continuing to "dns".  Thus, the
+       line
+       
+         hosts: mdns4_minimal [NOTFOUND=return] dns mdns4
+
+       does work because "status" will contain UNAVAIL after the
+       failure to find mdns4_minimal. */
+    ./nss-skip-unavail.patch
+  ];
+
   # `--with-tls --without-__thread' enables support for TLS but causes
   # it not to be used.  Required if we don't want to barf on 2.4
   # kernels.  Or something.

pkgs/development/libraries/glibc-2.7/nss-skip-unavail.patch

@@ -0,0 +1,25 @@
+diff -rc glibc-2.7-orig/sysdeps/posix/getaddrinfo.c glibc-2.7/sysdeps/posix/getaddrinfo.c
+*** glibc-2.7-orig/sysdeps/posix/getaddrinfo.c	2007-10-17 18:05:12.000000000 +0200
+--- glibc-2.7/sysdeps/posix/getaddrinfo.c	2008-04-08 12:17:09.000000000 +0200
+***************
+*** 498,505 ****
+  	  int no_data = 0;
+  	  int no_inet6_data = 0;
+  	  service_user *nip = NULL;
+- 	  enum nss_status inet6_status = NSS_STATUS_UNAVAIL;
+- 	  enum nss_status status = NSS_STATUS_UNAVAIL;
+  	  int no_more;
+  	  int old_res_options;
+  
+--- 498,503 ----
+***************
+*** 689,694 ****
+--- 687,694 ----
+  
+  	  while (!no_more)
+  	    {
++               enum nss_status inet6_status = NSS_STATUS_UNAVAIL;
++               enum nss_status status = NSS_STATUS_UNAVAIL;
+  	      nss_gethostbyname3_r fct = NULL;
+  	      if (req->ai_flags & AI_CANONNAME)
+  		/* No need to use this function if we do not look for