[Bug-readline] Re: PATCH: PR tui/2173: Arrow keys no longer works in breakpoint command list

[H. J. Lu]

On Tue, Nov 28, 2006 at 08:58:44AM -0800, H. J. Lu wrote:
> On Tue, Nov 28, 2006 at 11:46:58AM -0500, Daniel Jacobowitz wrote:
> > On Tue, Nov 21, 2006 at 01:32:05PM -0800, H. J. Lu wrote:
> > > The problem is callback in readline 5.1 is changed. When gdb readline
> > > callback calls readline (), readline is really confused since although
> > > it is called from gdb callback, it isn't really in callback state. This
> > > kludge seems to work for me.
> > 
> > I'm pretty sure this isn't right.  I got as far as figuring out that we
> > should be calling rl_callback_handler_install and
> > rl_callback_handler_remove at different times, always removing the
> > handler before calling readline recursively, but I couldn't quite work
> > out the right conditions.
> 
> I assume by "this isn't right",  you mean my patch may break something.
> Do you have a testcase? It may get into readline:
> 
> http://lists.gnu.org/archive/html/bug-readline/2006-11/msg00011.html
> 
> 

Here is the updated patch for readline.

(gdb) define foo
> <Control-C>

works with it.


H.J.
----
2006-12-02  H.J. Lu  <address@hidden>
            Jan Kratochvil <address@hidden>

        PR tui/2173
        * readline.c (readline): Unset and reset RL_STATE_CALLBACK if
        needed.

Index: readline/readline.c
===================================================================
RCS file: /cvs/src/src/readline/readline.c,v
retrieving revision 1.10
diff -u -p -r1.10 readline.c
--- readline/readline.c 5 May 2006 18:26:12 -0000       1.10
+++ readline/readline.c 22 Nov 2006 19:40:17 -0000
@@ -295,6 +295,7 @@ readline (prompt)
      const char *prompt;
 {
   char *value;
+  int in_callback;
 
   /* If we are at EOF return a NULL string. */
   if (rl_pending_input == EOF)
@@ -303,6 +304,13 @@ 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.  */
+  in_callback = RL_ISSTATE (RL_STATE_CALLBACK);
+  if (in_callback)
+    RL_UNSETSTATE (RL_STATE_CALLBACK);
+
   rl_set_prompt (prompt);
 
   rl_initialize ();
@@ -321,6 +329,9 @@ readline (prompt)
   rl_clear_signals ();
 #endif
 
+  if (in_callback)
+    RL_SETSTATE (RL_STATE_CALLBACK);
+
   return (value);
 }