Make sure terminal settings are restored before exiting

When exiting GDB -- whether it's via the "quit" command, via a SIGTERM,
or otherwise -- we should leave the terminal in the state we acquired
it.  To that end, we have to undo any modifications that may have been
made by the TUI (ncurses) or by the CLI (readline).

Tested on x86_64 Debian Stretch.

gdb/ChangeLog:

	* top.c: Include "tui/tui.h".
	(undo_terminal_modifications_before_exit): New static function.
	(quit_force): Use it.

gdb/testsuite/ChangeLog:

	* gdb.base/batch-preserve-term-settings.exp
	(test_terminal_settings_preserved_after_cli_exit): New test.

1 files changed, 21 insertions, 0 deletions

diff --git a/gdb/top.c b/gdb/top.c
index 1e30b1c..3e88ac6 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -67,6 +67,10 @@
 #include "tracepoint.h"
 #include "inf-loop.h"
 
+#if defined(TUI)
+# include "tui/tui.h"
+#endif
+
 extern void initialize_all_files (void);
 
 #define PROMPT(X) the_prompts.prompt_stack[the_prompts.top + X].prompt
@@ -1486,6 +1490,21 @@ quit_confirm (void)
   return qr;
 }
 
+/* Prepare to exit GDB cleanly by undoing any changes made to the
+   terminal so that we leave the terminal in the state we acquired it.  */
+
+static void
+undo_terminal_modifications_before_exit (void)
+{
+  target_terminal_ours ();
+#if defined(TUI)
+  tui_disable ();
+#endif
+  if (async_command_editing_p)
+    gdb_disable_readline ();
+}
+
+
 /* Quit without asking for confirmation.  */
 
 void
@@ -1494,6 +1513,8 @@ quit_force (char *args, int from_tty)
   int exit_code = 0;
   struct qt_args qt;
 
+  undo_terminal_modifications_before_exit ();
+
   /* An optional expression may be used to cause gdb to terminate with the 
      value of that expression.  */
   if (args)