Index: Makefile.in
===================================================================
--- Makefile.in	(revision 37263)
+++ Makefile.in	(working copy)
@@ -43,6 +43,7 @@ SVN_APRUTIL_LIBS = @SVN_APRUTIL_LIBS@
 SVN_APR_MEMCACHE_LIBS = @SVN_APR_MEMCACHE_LIBS@
 SVN_DB_LIBS = @SVN_DB_LIBS@
 SVN_GNOME_KEYRING_LIBS = @SVN_GNOME_KEYRING_LIBS@
+SVN_GSSAPI_LIBS = @SVN_GSSAPI_LIBS@
 SVN_KWALLET_LIBS = @SVN_KWALLET_LIBS@
 SVN_SASL_LIBS = @SVN_SASL_LIBS@
 SVN_SERF_LIBS = @SVN_SERF_LIBS@
@@ -58,6 +59,7 @@ fsmod_libdir = @libdir@
 ramod_libdir = @libdir@
 bdb_libdir = @libdir@
 gnome_keyring_libdir = @libdir@
+gssapi_libdir = @libdir@
 kwallet_libdir = @libdir@
 neon_libdir = @libdir@
 serf_libdir = @libdir@
@@ -112,7 +114,9 @@ LT_CXX_LIBADD = @LT_CXX_LIBADD@
 
 INCLUDES = -I$(top_srcdir)/subversion/include -I$(top_builddir)/subversion \
            @SVN_APR_INCLUDES@ @SVN_APRUTIL_INCLUDES@ @SVN_APR_MEMCACHE_INCLUDES@ \
-           @SVN_DB_INCLUDES@ @SVN_GNOME_KEYRING_INCLUDES@ @SVN_KWALLET_INCLUDES@ \
+           @SVN_DB_INCLUDES@ @SVN_GNOME_KEYRING_INCLUDES@ \
+           @SVN_GSSAPI_INCLUDES@ \
+           @SVN_KWALLET_INCLUDES@ \
            @SVN_NEON_INCLUDES@ @SVN_SASL_INCLUDES@ @SVN_SERF_INCLUDES@ \
            @SVN_SQLITE_INCLUDES@ @SVN_ZLIB_INCLUDES@
 
@@ -208,6 +212,7 @@ INSTALL_RAMOD_LIB = $(INSTALL_LIB)
 INSTALL_APR_MEMCACHE_LIB = $(INSTALL_LIB)
 INSTALL_BDB_LIB = $(INSTALL_LIB)
 INSTALL_GNOME_KEYRING_LIB = $(INSTALL_LIB)
+INSTALL_GSSAPI_LIB = $(INSTALL_LIB)
 INSTALL_KWALLET_LIB = $(INSTALL_LIB)
 INSTALL_NEON_LIB = $(INSTALL_LIB)
 INSTALL_SERF_LIB = $(INSTALL_LIB)
Index: build.conf
===================================================================
--- build.conf	(revision 37263)
+++ build.conf	(working copy)
@@ -935,6 +935,10 @@ external-lib = $(SVN_DB_LIBS)
 type = lib
 external-lib = $(SVN_GNOME_KEYRING_LIBS)
 
+[gssapi]
+type = lib
+external-lib = $(SVN_GSSAPI_LIBS)
+
 [kwallet]
 type = lib
 external-lib = $(SVN_KWALLET_LIBS)
Index: build/ac-macros/gssapi.m4
===================================================================
--- build/ac-macros/gssapi.m4	(revision 0)
+++ build/ac-macros/gssapi.m4	(revision 0)
@@ -0,0 +1,37 @@
+dnl
+dnl  SVN_LIB_GSSAPI
+dnl
+dnl  Check configure options and assign variables related to
+dnl  the gssapi library.
+dnl
+
+AC_DEFUN(SVN_LIB_RA_SERF_GSSAPI,
+[
+  gssapi_found=no
+
+  AC_ARG_WITH(gssapi,AS_HELP_STRING([--with-gssapi=PREFIX],
+                                  [GSSAPI (Kerberos) support]),
+  [
+    if test "$withval" = "yes" ; then
+      AC_MSG_ERROR([--with-gssapi requires an argument.])
+    elif test "$withval" != "no" ; then
+      AC_MSG_NOTICE([GSSAPI configuration])
+      gssapi_prefix=$withval
+      save_cppflags="$CPPFLAGS"
+      CPPFLAGS="$CPPFLAGS -I$gssapi_prefix/include/gssapi"
+      AC_CHECK_HEADERS(gssapi.h, [
+        save_ldflags="$LDFLAGS"
+        LDFLAGS="$LDFLAGS -L$gssapi_prefix/lib"
+        AC_CHECK_LIB(gssapi_krb5, gss_init_sec_context, [gssapi_found="yes"])
+        LDFLAGS="$save_ldflags"])
+      CPPFLAGS="$save_cppflags"
+    fi
+  ])
+
+  svn_lib_gssapi=$gssapi_found
+
+  AC_SUBST(SVN_GSSAPI_PREFIX)
+  AC_SUBST(SVN_GSSAPI_INCLUDES)
+  AC_SUBST(SVN_GSSAPI_LIBS)
+  AC_SUBST(SVN_GSSAPI_EXPORT_LIBS)
+])
Index: subversion/libsvn_ra_serf/auth.c
===================================================================
--- subversion/libsvn_ra_serf/auth.c	(revision 37263)
+++ subversion/libsvn_ra_serf/auth.c	(working copy)
@@ -119,7 +119,7 @@ static const svn_ra_serf__auth_protocol_t serf_aut
     svn_ra_serf__setup_request_digest_auth,
     svn_ra_serf__validate_response_digest_auth,
   },
-#if SVN_RA_SERF_GSSAPI_ENABLED
+#if SVN_RA_SERF_HAVE_GSSAPI
   {
     401,
     "Negotiate",
@@ -128,7 +128,7 @@ static const svn_ra_serf__auth_protocol_t serf_aut
     svn_ra_serf__setup_request_kerb_auth,
     svn_ra_serf__validate_response_kerb_auth,    
   },
-#endif /* SVN_RA_SERF_GSSAPI_ENABLED */
+#endif /* SVN_RA_SERF_HAVE_GSSAPI */
 
   /* ADD NEW AUTHENTICATION IMPLEMENTATIONS HERE (as they're written) */
 
Index: subversion/libsvn_ra_serf/auth_kerb.c
===================================================================
--- subversion/libsvn_ra_serf/auth_kerb.c	(revision 37263)
+++ subversion/libsvn_ra_serf/auth_kerb.c	(working copy)
@@ -16,15 +16,15 @@
  * ====================================================================
  */
 
-#ifdef SVN_RA_SERF_GSSAPI_ENABLED
+#include "svn_private_config.h"
 
+#ifdef SVN_RA_SERF_HAVE_GSSAPI
+
 #include <string.h>
-
 #include <apr.h>
 #include <apr_base64.h>
 #include <gssapi/gssapi.h>
 #include "svn_error.h"
-#include "svn_private_config.h"
 #include "ra_serf.h"
 #include "auth_kerb.h"
 
@@ -301,4 +301,4 @@ svn_ra_serf__validate_response_kerb_auth(svn_ra_se
   return SVN_NO_ERROR;
 }
 
-#endif /* SVN_RA_SERF_GSSAPI_ENABLED */
+#endif /* SVN_RA_SERF_HAVE_GSSAPI */
Index: configure.ac
===================================================================
--- configure.ac	(revision 37263)
+++ configure.ac	(working copy)
@@ -110,6 +110,14 @@ if test "$svn_lib_serf" = "yes"; then
             [Defined if support for Serf is enabled])
 fi
 
+dnl Search for GSSAPI
+SVN_LIB_RA_SERF_GSSAPI
+
+if test "$svn_lib_gssapi" = "yes"; then
+  AC_DEFINE([SVN_RA_SERF_HAVE_GSSAPI], 1,
+            [Defined if support for GSSAPI is enabled])
+fi
+
 dnl Search for apr_memcache (only affects fs_fs)
 SVN_LIB_APR_MEMCACHE
 
Index: aclocal.m4
===================================================================
--- aclocal.m4	(revision 37263)
+++ aclocal.m4	(working copy)
@@ -17,6 +17,7 @@ sinclude(build/ac-macros/aprutil.m4)
 sinclude(build/ac-macros/apr_memcache.m4)
 sinclude(build/ac-macros/berkeley-db.m4)
 sinclude(build/ac-macros/ctypesgen.m4)
+sinclude(build/ac-macros/gssapi.m4)
 sinclude(build/ac-macros/java.m4)
 sinclude(build/ac-macros/neon.m4)
 sinclude(build/ac-macros/sasl.m4)