[Pidgin] #4537: [libpurple]unportable use of resolver library

[Pidgin]

#4537: [libpurple]unportable use of resolver library
----------------------------+-----------------------------------------------
 Reporter:  francois        |       Type:  defect
   Status:  new             |   Priority:  minor 
Component:  libpurple       |    Version:  2.3.1 
 Keywords:  BIND, resolver  |    Pending:  0     
----------------------------+-----------------------------------------------
 == Problem ==
 libpurple won't compile against a BIND 8 compatible resolver library

 == How to reproduce ==
 trying to add a CFLAGS=-DBIND_8_COMPAT and compilation will fail for
 libpurple/network.c and libpurple/dnssrv.c

 == Cause ==
 those two files badly include headers for the resolver library.
 As stated in the man page of resolver, headers should be included in this
 order :
 {{{
 #!c
      #include <arpa/nameser.h>
      #include <resolv.h>
 }}}
 and not
 {{{
 #!c
      #include <resolv.h>
      #include <arpa/nameser.h>
 }}}
 nor
 {{{
 #!c
      #include <resolv.h>
 }}}

 == Full story ==
 When linking libpurple/example/nullclient against a static libresolv.a, I
 got an error message claiming unresolved dependencies for _res_9_dn_expand
 and _res_9_query.  After unluckily looking for those symbols in my
 library, I realized it wasn't compiled against BIND 9, so I needed to
 define BIND_8_COMPAT.

 == Workaround ==
 {{{
 --- libpurple/dnssrv.c
 +++ libpurple/dnssrv.c
 @@ -25,11 +25,13 @@
  #include "util.h"

  #ifndef _WIN32
 -#include <resolv.h>
  #include <arpa/nameser.h>
 +#include <resolv.h>
 +#ifndef BIND_8_COMPAT
  #ifdef HAVE_ARPA_NAMESER_COMPAT_H
  #include <arpa/nameser_compat.h>
  #endif
 +#endif
  #ifndef T_SRV
  #define T_SRV  33
  #endif


 --- libpurple/network.c
 +++ libpurple/network.c
 @@ -27,6 +27,7 @@
  #include "internal.h"

  #ifndef _WIN32
 +#include <arpa/nameser.h>
  #include <resolv.h>
  #include <netinet/in.h>
  #include <arpa/nameser.h>
 }}}

 == Note ==
 arpa/nameser8_compat.h is automatically included by arpa/nameser.h when
 BIND_8_COMPAT is defined.

-- 
Ticket URL: <http://developer.pidgin.im/ticket/4537>
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