Give a name to the TUI SingleKey keymap

Readline 8.0 has a feature that lets an application name a keymap.
This in turn makes it simpler for users to bind keys in keymaps in
their .inputrc.

This patch gives a name to the TUI SingleKey keymap, so that
additional bindings can be made there.  For example:

    $if gdb
    set keymap SingleKey
    "X": "echo hello\\n\n"
    $endif

The call to rl_initialize, in tui_initialize_readline, had to be
removed so that .inputrc was not read too early.  Note that Readline
explicitly documents that this call is not needed.

gdb/ChangeLog
2019-09-18  Tom Tromey  <tom@tromey.com>

	* NEWS: Add entry.
	* tui/tui.c (tui_initialize_readline): Set name of keymap.  Do not
	call rl_initialize.
	(tui_enable): Do not call rl_initialize.

gdb/doc/ChangeLog
2019-09-18  Tom Tromey  <tom@tromey.com>

	* gdb.texinfo (Editing): Document readline application name.
	(TUI Single Key Mode): Document TUI SingleKey keymap name.

1 files changed, 6 insertions, 3 deletions

diff --git a/gdb/tui/tui.c b/gdb/tui/tui.c
index db34e0c..5d6b9f3 100644
--- a/gdb/tui/tui.c
+++ b/gdb/tui/tui.c
@@ -329,13 +329,17 @@ tui_initialize_readline (void)
   int i;
   Keymap tui_ctlx_keymap;
 
-  rl_initialize ();
-
   rl_add_defun ("tui-switch-mode", tui_rl_switch_mode, -1);
   rl_add_defun ("gdb-command", tui_rl_command_key, -1);
   rl_add_defun ("next-keymap", tui_rl_next_keymap, -1);
 
   tui_keymap = rl_make_bare_keymap ();
+
+  /* The named keymap feature was added in Readline 8.0.  */
+#if RL_READLINE_VERSION >= 0x800
+  rl_set_keymap_name ("SingleKey", tui_keymap);
+#endif
+
   tui_ctlx_keymap = rl_make_bare_keymap ();
   tui_readline_standard_keymap = rl_get_keymap ();
 
@@ -467,7 +471,6 @@ tui_enable (void)
       nodelay(w, FALSE);
       nl();
       keypad (w, TRUE);
-      rl_initialize ();
       tui_set_term_height_to (LINES);
       tui_set_term_width_to (COLS);
       def_prog_mode ();