* NEWS: Updated.

* event-loop.c (start_event_loop): Call
	after_char_processing_hook.
	* event-top.h (after_char_processing_hook): Declare.
	* event-top.c (rl_callback_read_char_wrapper): Call
	after_char_processing_hook.
	(after_char_processing_hook): New global.
	* top.c (operate_saved_history): New global.
	(gdb_rl_operate_and_get_next): New function.
	(init_main): Add the operate-and-get-next defun.
	(gdb_rl_operate_and_get_next_completion): New function.

gdb/ChangeLog

@@ -1,3 +1,17 @@
+2001-11-26  Tom Tromey  <tromey@redhat.com>
+
+	* NEWS: Updated.
+	* event-loop.c (start_event_loop): Call
+	after_char_processing_hook.
+	* event-top.h (after_char_processing_hook): Declare.
+	* event-top.c (rl_callback_read_char_wrapper): Call
+	after_char_processing_hook.
+	(after_char_processing_hook): New global.
+	* top.c (operate_saved_history): New global.
+	(gdb_rl_operate_and_get_next): New function.
+	(init_main): Add the operate-and-get-next defun.
+	(gdb_rl_operate_and_get_next_completion): New function.
+
 2001-11-26  Tom Tromey  <tromey@redhat.com>
 
 	* NEWS: Update for --args.

gdb/NEWS

@@ -12,6 +12,10 @@ x86 OpenBSD					i[3456]86-*-openbsd*
 The new `--args' feature can be used to specify command-line arguments
 for the inferior from gdb's command line.
 
+* Changes to key bindings
+
+There is a new `operate-and-get-next' function bound to `C-o'.
+
 *** Changes in GDB 5.1:
 
 * New native configurations

gdb/event-loop.c

@@ -402,6 +402,14 @@ start_event_loop (void)
 	     interface specific, because interfaces can display the
 	     prompt in their own way. */
 	  display_gdb_prompt (0);
+	  /* This call looks bizarre, but it is required.  If the user
+	     entered a command that caused an error,
+	     after_char_processing_hook won't be called from
+	     rl_callback_read_char_wrapper.  Using a cleanup there
+	     won't work, since we want this function to be called
+	     after a new prompt is printed.  */
+	  if (after_char_processing_hook)
+	    (*after_char_processing_hook) ();
 	  /* Maybe better to set a flag to be checked somewhere as to
 	     whether display the prompt or not. */
 	}

gdb/event-top.c

@@ -153,6 +153,10 @@ struct readline_input_state
     char *linebuffer_ptr;
   }
 readline_input_state;
+
+/* This hook is called by rl_callback_read_char_wrapper after each
+   character is processed.  */
+void (*after_char_processing_hook) ();
 
 
 /* Wrapper function for calling into the readline library. The event
@@ -162,6 +166,8 @@ static void
 rl_callback_read_char_wrapper (gdb_client_data client_data)
 {
   rl_callback_read_char ();
+  if (after_char_processing_hook)
+    (*after_char_processing_hook) ();
 }
 
 /* Initialize all the necessary variables, start the event loop,

gdb/event-top.h

@@ -108,3 +108,4 @@ extern struct prompts the_prompts;
 extern void (*call_readline) (void *);
 extern void (*input_handler) (char *);
 extern int input_fd;
+extern void (*after_char_processing_hook) (void);

gdb/top.c

@@ -1035,6 +1035,52 @@ init_signals (void)
 #endif
 }
 
+/* The current saved history number from operate-and-get-next.
+   This is -1 if not valid.  */
+static int operate_saved_history = -1;
+
+/* This is put on the appropriate hook and helps operate-and-get-next
+   do its work.  */
+void
+gdb_rl_operate_and_get_next_completion ()
+{
+  int delta = where_history () - operate_saved_history;
+  /* The `key' argument to rl_get_previous_history is ignored.  */
+  rl_get_previous_history (delta, 0);
+  operate_saved_history = -1;
+
+  /* readline doesn't automatically update the display for us.  */
+  rl_redisplay ();
+
+  after_char_processing_hook = NULL;
+  rl_pre_input_hook = NULL;
+}
+
+/* This is a gdb-local readline command handler.  It accepts the
+   current command line (like RET does) and, if this command was taken
+   from the history, arranges for the next command in the history to
+   appear on the command line when the prompt returns.
+   We ignore the arguments.  */
+static int
+gdb_rl_operate_and_get_next (int count, int key)
+{
+  if (event_loop_p)
+    {
+      /* Use the async hook.  */
+      after_char_processing_hook = gdb_rl_operate_and_get_next_completion;
+    }
+  else
+    {
+      /* This hook only works correctly when we are using the
+	 synchronous readline.  */
+      rl_pre_input_hook = (Function *) gdb_rl_operate_and_get_next_completion;
+    }
+
+  /* Add 1 because we eventually want the next line.  */
+  operate_saved_history = where_history () + 1;
+  return rl_newline (1, key);
+}
+
 /* Read one line from the command input stream `instream'
    into the local static buffer `linebuffer' (whose current length
    is `linelength').
@@ -1880,6 +1926,10 @@ init_main (void)
   rl_completer_quote_characters = get_gdb_completer_quote_characters ();
   rl_readline_name = "gdb";
 
+  /* The name for this defun comes from Bash, where it originated.
+     15 is Control-o, the same binding this function has in Bash.  */
+  rl_add_defun ("operate-and-get-next", gdb_rl_operate_and_get_next, 15);
+
   /* The set prompt command is different depending whether or not the
      async version is run. NOTE: this difference is going to
      disappear as we make the event loop be the default engine of