GDB PR 544: gdb.cp/annota2.exp and gdb.cp/annota3.exp sometimes FAIL with:
	FAIL: gdb.cp/annota3.exp: annotate-quit (pattern 1)

One can put `sleep (1)' at the end of _RL_OUTPUT_SOME_CHARS and type
	p 1<enter><ctrl-c>
to abort the prompt printing. Before the patch:
	(gdb) p 1
	$1 = 1
	Quit) (gdb) 
	(gdb) _
After the patch:
	[bash]jkratoch@host0.dyn.jankratochvil.net:/home/jkratoch/redhat/sources/readline# ../gdb/gdb -nx -silent(gdb) p 1
	$1 = 1
	(gdb) Quit
	(gdb) _

The readline patch posted upstream:
	http://sourceware.org/ml/gdb-patches/2008-03/msg00317.html

On Fri, 21 Mar 2008 19:37:31 +0100, Chet Ramey wrote:
> I will add something like your block_sigint/release_sigint changes around
> the guts of rl_redisplay.  That's the right thing to do anyway.  It will
> probably not come out as a patch for readline-5.2; you can use your
> current patch (though the names will change to _rl_block_sigint and
> _rl_release_sigint -- fair warning).

Application cannot easily supply its own RL_REDISPLAY_FUNCTION as a custom
function there changes the readline behavior:
	http://sourceware.org/ml/gdb-patches/2008-03/msg00340.html

BLOCK_SIGINT / RELEASE_SIGINT: Make it public and prefix it by `_rl_'.
RL_REDISPLAY: Wrap it by _RL_BLOCK_SIGINT / _RL_RELEASE_SIGINT.

--- readline-5.2-orig/display.c	2008-03-23 20:52:12.000000000 +0100
+++ readline-5.2/display.c	2008-03-23 20:56:58.000000000 +0100
@@ -472,6 +472,10 @@ rl_redisplay ()
   if (!readline_echoing_p)
     return;
 
+  /* Signals are blocked through this function as the global data structures
+     could get corrupted upon modifications from an invoked signal handler. */
+  _rl_block_sigint ();
+
   if (!rl_display_prompt)
     rl_display_prompt = "";
 
@@ -1180,6 +1184,8 @@ rl_redisplay ()
     else
       visible_wrap_offset = wrap_offset;
   }
+
+  _rl_release_sigint ();
 }
 
 /* PWP: update_line() is based on finding the middle difference of each
--- readline-5.2-orig/rltty.c	2005-12-26 23:21:50.000000000 +0100
+++ readline-5.2/rltty.c	2008-03-23 20:57:26.000000000 +0100
@@ -52,8 +52,8 @@ extern int errno;
 rl_vintfunc_t *rl_prep_term_function = rl_prep_terminal;
 rl_voidfunc_t *rl_deprep_term_function = rl_deprep_terminal;
 
-static void block_sigint PARAMS((void));
-static void release_sigint PARAMS((void));
+void _rl_block_sigint PARAMS((void));
+void _rl_release_sigint PARAMS((void));
 
 static void set_winsize PARAMS((int));
 
@@ -74,9 +74,9 @@ static int sigint_oldmask;
 static int sigint_blocked;
 
 /* Cause SIGINT to not be delivered until the corresponding call to
-   release_sigint(). */
-static void
-block_sigint ()
+   _rl_release_sigint(). */
+void
+_rl_block_sigint ()
 {
   if (sigint_blocked)
     return;
@@ -100,8 +100,8 @@ block_sigint ()
 }
 
 /* Allow SIGINT to be delivered. */
-static void
-release_sigint ()
+void
+_rl_release_sigint ()
 {
   if (sigint_blocked == 0)
     return;
@@ -663,7 +663,7 @@ rl_prep_terminal (meta_flag)
     return;
 
   /* Try to keep this function from being INTerrupted. */
-  block_sigint ();
+  _rl_block_sigint ();
 
   tty = fileno (rl_instream);
 
@@ -676,7 +676,7 @@ rl_prep_terminal (meta_flag)
       if (errno == ENOTTY)
 #endif
 	readline_echoing_p = 1;		/* XXX */
-      release_sigint ();
+      _rl_release_sigint ();
       return;
     }
 
@@ -711,7 +711,7 @@ rl_prep_terminal (meta_flag)
 
   if (set_tty_settings (tty, &tio) < 0)
     {
-      release_sigint ();
+      _rl_release_sigint ();
       return;
     }
 
@@ -722,7 +722,7 @@ rl_prep_terminal (meta_flag)
   terminal_prepped = 1;
   RL_SETSTATE(RL_STATE_TERMPREPPED);
 
-  release_sigint ();
+  _rl_release_sigint ();
 }
 
 /* Restore the terminal's normal settings and modes. */
@@ -735,7 +735,7 @@ rl_deprep_terminal ()
     return;
 
   /* Try to keep this function from being interrupted. */
-  block_sigint ();
+  _rl_block_sigint ();
 
   tty = fileno (rl_instream);
 
@@ -746,14 +746,14 @@ rl_deprep_terminal ()
 
   if (set_tty_settings (tty, &otio) < 0)
     {
-      release_sigint ();
+      _rl_release_sigint ();
       return;
     }
 
   terminal_prepped = 0;
   RL_UNSETSTATE(RL_STATE_TERMPREPPED);
 
-  release_sigint ();
+  _rl_release_sigint ();
 }
 #endif /* !NO_TTY_DRIVER */
 
--- readline-5.2-orig/rltty.h	2003-02-01 04:43:11.000000000 +0100
+++ readline-5.2/rltty.h	2008-03-23 20:57:30.000000000 +0100
@@ -79,4 +79,7 @@ typedef struct _rl_tty_chars {
   unsigned char t_status;
 } _RL_TTY_CHARS;
 
+extern void _rl_block_sigint PARAMS((void));
+extern void _rl_release_sigint PARAMS((void));
+
 #endif /* _RLTTY_H_ */