2007-06-26  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* top.c (gdb_readline_wrapper) Wrap readline() by readline_cleanup().
	(readline_cleanup): New function.

2007-06-26  Jan Kratochvil  <jan.kratochvil@redhat.com>
	    H.J. Lu  <hongjiu.lu@intel.com>

	PR tui/2173
	* readline.c (readline): Save/restore RL_STATE_CALLBACK into STATE_LIST.
	(rl_readline_unwind, struct state, state_list): New.
	* readline.h (rl_readline_unwind): New declaration.

2007-06-26  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* rltech.texi (Readline Signal Handling): Describe rl_readline_unwind().

--- sources-unpatched/gdb/top.c	2007-06-26 13:04:11.000000000 +0200
+++ sources/gdb/top.c	2007-06-26 12:38:43.000000000 +0200
@@ -706,6 +706,13 @@ The filename in which to record the comm
 		    value);
 }
 
+static void
+readline_cleanup (void *unused)
+{
+  /* No need to check for it by autoconf as libreadline is bundled with GDB.  */
+  rl_readline_unwind ();
+}
+
 /* This is like readline(), but it has some gdb-specific behavior.
    gdb can use readline in both the synchronous and async modes during
    a single gdb invocation.  At the ordinary top-level prompt we might
@@ -719,6 +726,9 @@ The filename in which to record the comm
 char *
 gdb_readline_wrapper (char *prompt)
 {
+  char *retval;
+  struct cleanup *cleanups;
+
   /* Set the hook that works in this case.  */
   if (after_char_processing_hook)
     {
@@ -726,7 +736,11 @@ gdb_readline_wrapper (char *prompt)
       after_char_processing_hook = NULL;
     }
 
-  return readline (prompt);
+  cleanups = make_cleanup (readline_cleanup, NULL);
+  retval = readline (prompt);
+  discard_cleanups (cleanups);
+
+  return retval;
 }
 
 
--- sources-unpatched/readline/doc/rltech.texi	2007-06-26 12:54:57.000000000 +0200
+++ sources/readline/doc/rltech.texi	2007-06-26 12:40:50.000000000 +0200
@@ -1336,7 +1336,16 @@ resetting the terminal to its original s
 handler does more than update its idea of the terminal size and return (for
 example, a @code{longjmp} back to a main processing loop), it @emph{must}
 call @code{rl_cleanup_after_signal()} (described below), to restore the
-terminal state. 
+terminal state.  Each @code{longjmp} call must be also protected by
+@code{rl_readline_unwind()}:
+
+@deftypefun void rl_readline_unwind (void)
+Each @code{readline()} call you jump out of by @code{longjmp} must be matched
+by one call of this function.  It is appropriate to call it from your
+@code{catch} part of the C++ exception handler.  This functiona must not be
+called if @code{readline()} returns itself.  If you do not abort
+@code{readline()} by @code{longjmp} you must never call this function.
+@end deftypefun
 
 Readline provides two variables that allow application writers to
 control whether or not it will catch certain signals and act on them
--- sources-unpatched/readline/readline.c	2007-06-26 12:54:52.000000000 +0200
+++ sources/readline/readline.c	2007-06-26 12:33:57.000000000 +0200
@@ -287,7 +287,27 @@ rl_set_prompt (prompt)
   rl_visible_prompt_length = rl_expand_prompt (rl_prompt);
   return 0;
 }
-  
+
+struct state {
+  struct state *next;
+  int in_callback;
+};
+static struct state *state_list;
+
+/* To be called once for each readline () call which you have jumped out of by
+   longjmp() or siglongjmp().  Function needs to be called BEFORE the jump.  */
+void
+rl_readline_unwind ()
+{
+  /* NULL should not happen.  */
+  if (state_list != NULL)
+    {
+      if (state_list->in_callback)
+	RL_SETSTATE (RL_STATE_CALLBACK);
+      state_list = state_list->next;
+    }
+}
+
 /* Read a line of input.  Prompt with PROMPT.  An empty PROMPT means
    none.  A return value of NULL means that EOF was encountered. */
 char *
@@ -295,6 +315,7 @@ readline (prompt)
      const char *prompt;
 {
   char *value;
+  struct state state;
 
   /* If we are at EOF return a NULL string. */
   if (rl_pending_input == EOF)
@@ -303,6 +324,15 @@ readline (prompt)
       return ((char *)NULL);
     }
 
+  /* When we call readline, we have to make sure that readline isn't in
+     the callback state. Otherwise, it will get really confused.
+     PR gdb tui/2173.  */
+  state.next = state_list;
+  state_list = &state;
+  state.in_callback = RL_ISSTATE (RL_STATE_CALLBACK);
+  if (state.in_callback)
+    RL_UNSETSTATE (RL_STATE_CALLBACK);
+
   rl_set_prompt (prompt);
 
   rl_initialize ();
@@ -321,6 +351,8 @@ readline (prompt)
   rl_clear_signals ();
 #endif
 
+  rl_readline_unwind ();
+
   return (value);
 }
 
--- sources-unpatched/readline/readline.h	2007-06-26 12:54:52.000000000 +0200
+++ sources/readline/readline.h	2007-06-26 12:34:00.000000000 +0200
@@ -280,6 +280,10 @@ extern int rl_vi_eword PARAMS((int, int)
 /* Read a line of input.  Prompt with PROMPT.  A NULL PROMPT means none. */
 extern char *readline PARAMS((const char *));
 
+/* To be called once for each readline () call which you have jumped out of by
+   longjmp() or siglongjmp().  Function needs to be called BEFORE the jump.  */
+extern void rl_readline_unwind PARAMS((void));
+
 extern int rl_set_prompt PARAMS((const char *));
 extern int rl_expand_prompt PARAMS((char *));