[binutils-gdb] Make isearch change readline prompt in TUI

[gdb-buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 364d710448e607e4ae9cb338583179dd6e734f0b ***

commit 364d710448e607e4ae9cb338583179dd6e734f0b
Author:     Tom Tromey <tom@tromey.com>
AuthorDate: Wed Nov 20 16:39:44 2019 -0700
Commit:     Tom Tromey <tom@tromey.com>
CommitDate: Fri Dec 20 08:49:52 2019 -0700

    Make isearch change readline prompt in TUI
    
    PR tui/23619 points out that isearch changes the prompt in the CLI gdb
    (and in Bash) -- but not in the TUI.  This turns out to be easily
    fixed by removing tui_rl_saved_prompt and instead using the prompt
    that readline computes.
    
    This is stored in rl_display_prompt, which according to git was added
    in readline 6.2.
    
    gdb/ChangeLog
    2019-12-20  Tom Tromey  <tom@tromey.com>
    
            PR tui/23619:
            * tui/tui-io.c (tui_rl_saved_prompt): Remove.
            (tui_redisplay_readline): Use rl_display_prompt.
            (tui_prep_terminal): Update.
    
    Change-Id: Iae97e9776a5540bbe52c73b05e4707941d9cd11a

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f7c84c01c9..1b838b9189 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2019-12-20  Tom Tromey  <tom@tromey.com>
+
+	PR tui/23619:
+	* tui/tui-io.c (tui_rl_saved_prompt): Remove.
+	(tui_redisplay_readline): Use rl_display_prompt.
+	(tui_prep_terminal): Update.
+
 2019-12-19  Christian Biesinger  <cbiesinger@google.com>
 
 	* configure: Regenerate.
diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c
index 2eef288bdb..d902d9e920 100644
--- a/gdb/tui/tui-io.c
+++ b/gdb/tui/tui-io.c
@@ -131,10 +131,6 @@ static FILE *tui_old_rl_outstream;
 static int tui_readline_pipe[2];
 #endif
 
-/* The last gdb prompt that was registered in readline.
-   This may be the main gdb prompt or a secondary prompt.  */
-static char *tui_rl_saved_prompt;
-
 /* Print a character in the curses command window.  The output is
    buffered.  It is up to the caller to refresh the screen if
    necessary.  */
@@ -538,7 +534,7 @@ tui_redisplay_readline (void)
   if (tui_current_key_mode == TUI_SINGLE_KEY_MODE)
     prompt = "";
   else
-    prompt = tui_rl_saved_prompt;
+    prompt = rl_display_prompt;
   
   c_pos = -1;
   c_line = -1;
@@ -606,11 +602,6 @@ tui_redisplay_readline (void)
 static void
 tui_prep_terminal (int notused1)
 {
-  /* Save the prompt registered in readline to correctly display it.
-     (we can't use gdb_prompt() due to secondary prompts and can't use
-     rl_prompt because it points to an alloca buffer).  */
-  xfree (tui_rl_saved_prompt);
-  tui_rl_saved_prompt = rl_prompt != NULL ? xstrdup (rl_prompt) : NULL;
 }
 
 /* Readline callback to restore the terminal.  It is called once each