Patch 659834 by Magnus Lie Hetland:

Check for readline 2.2 features.  This should make it possible to
compile readline.c again with GNU readline versions 2.0 or 2.1; this
ability was removed in readline.c rev. 2.49.  Apparently the older
versions are still in widespread deployment on older Solaris
installations.  With an older readline, completion behavior is subtly
different (a space is always added).

Modules/readline.c

@@ -574,7 +574,9 @@ setup_readline(void)
 	rl_completer_word_break_characters =
 		strdup(" \t\n`~!@#$%^&*()-=+[{]}\\|;:'\",<>/?");
 		/* All nonalphanums except '.' */
+#ifdef HAVE_RL_COMPLETION_APPEND_CHARACTER
 	rl_completion_append_character ='\0';
+#endif
 
 	begidx = PyInt_FromLong(0L);
 	endidx = PyInt_FromLong(0L);
@@ -626,7 +628,9 @@ call_readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
         if (sys_stdin != rl_instream || sys_stdout != rl_outstream) {
                 rl_instream = sys_stdin;
                 rl_outstream = sys_stdout;
+#ifdef HAVE_RL_COMPLETION_APPEND_CHARACTER
                 rl_prep_terminal (1);
+#endif
         }
         
 	p = readline(prompt);

configure

 #! /bin/sh
-# From configure.in Revision: 1.378 .
+# From configure.in Revision: 1.380 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53 for python 2.3.
 #
@@ -908,7 +908,7 @@ esac
 # Don't blindly perform a `cd "$ac_dir"/$ac_foo && pwd` since $ac_foo can be
 # absolute.
 ac_abs_builddir=`cd "$ac_dir" && cd $ac_builddir && pwd`
-ac_abs_top_builddir=`cd "$ac_dir" && cd ${ac_top_builddir}. && pwd`
+ac_abs_top_builddir=`cd "$ac_dir" && cd $ac_top_builddir && pwd`
 ac_abs_srcdir=`cd "$ac_dir" && cd $ac_srcdir && pwd`
 ac_abs_top_srcdir=`cd "$ac_dir" && cd $ac_top_srcdir && pwd`
 
@@ -16228,6 +16228,56 @@ _ACEOF
 
 fi
 
+# check for readline 2.2
+cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+#include "confdefs.h"
+#include <readline/readline.h>
+_ACEOF
+if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5
+  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
+  ac_status=$?
+  egrep -v '^ *\+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } >/dev/null; then
+  if test -s conftest.err; then
+    ac_cpp_err=$ac_c_preproc_warn_flag
+  else
+    ac_cpp_err=
+  fi
+else
+  ac_cpp_err=yes
+fi
+if test -z "$ac_cpp_err"; then
+  have_readline=yes
+else
+  echo "$as_me: failed program was:" >&5
+  cat conftest.$ac_ext >&5
+  have_readline=no
+fi
+rm -f conftest.err conftest.$ac_ext
+if test $have_readline = yes
+then
+  cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+#include "confdefs.h"
+#include <readline/readline.h>
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  egrep "extern int rl_completion_append_character;" >/dev/null 2>&1; then
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_RL_COMPLETION_APPEND_CHARACTER 1
+_ACEOF
+
+fi
+rm -f conftest*
+
+fi
+
 # check for readline 4.0
 echo "$as_me:$LINENO: checking for rl_pre_input_hook in -lreadline" >&5
 echo $ECHO_N "checking for rl_pre_input_hook in -lreadline... $ECHO_C" >&6
@@ -17418,7 +17468,7 @@ esac
 # Don't blindly perform a `cd "$ac_dir"/$ac_foo && pwd` since $ac_foo can be
 # absolute.
 ac_abs_builddir=`cd "$ac_dir" && cd $ac_builddir && pwd`
-ac_abs_top_builddir=`cd "$ac_dir" && cd ${ac_top_builddir}. && pwd`
+ac_abs_top_builddir=`cd "$ac_dir" && cd $ac_top_builddir && pwd`
 ac_abs_srcdir=`cd "$ac_dir" && cd $ac_srcdir && pwd`
 ac_abs_top_srcdir=`cd "$ac_dir" && cd $ac_top_srcdir && pwd`
 

configure.in

@@ -2381,6 +2381,17 @@ then
   [Define this if you have flockfile(), getc_unlocked(), and funlockfile()])
 fi
 
+# check for readline 2.2
+AC_TRY_CPP([#include <readline/readline.h>],
+have_readline=yes, have_readline=no)
+if test $have_readline = yes
+then
+  AC_EGREP_HEADER([extern int rl_completion_append_character;],
+  [readline/readline.h],
+  AC_DEFINE(HAVE_RL_COMPLETION_APPEND_CHARACTER, 1,
+  [Define if you have readline 2.2]), )
+fi
+
 # check for readline 4.0
 AC_CHECK_LIB(readline, rl_pre_input_hook,
 	AC_DEFINE(HAVE_RL_PRE_INPUT_HOOK, 1,

pyconfig.h.in

@@ -333,6 +333,9 @@
 /* Define to 1 if you have the `readlink' function. */
 #undef HAVE_READLINK
 
+/* Define if you have readline 2.2 */
+#undef HAVE_RL_COMPLETION_APPEND_CHARACTER
+
 /* Define if you have readline 4.2 */
 #undef HAVE_RL_COMPLETION_MATCHES